Immediate vs Delayed Left Bundle Branch Block after Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation

Immediate vs Delayed Left Bundle Branch Block after Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Immediate vs Delayed Left Bundle Branch Block after Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation Maayan Shrem, Oholi Tovia-Brodie, Moshe Rav Acha, Ziv Dadon, Maxime Zabern, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8121179/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 19 Feb, 2026 Read the published version in Journal of Interventional Cardiac Electrophysiology → Version 1 posted You are reading this latest preprint version Abstract Background : Characteristics of patients with delayed compared to immediate new onset left bundle branch block (LBBB) after trans catheter aortic valve replacement (TAVR) are poorly defined. Objectives : To describe the incidence and features of patients with delayed post TAVR LBBB as well as risk factors for permanent pacemaker implantation (PPI). Methods : 1469 consecutive TAVR patients were screened for the occurrence of new onset LBBB. ECG was performed within 1 week before the procedure, immediately post procedure, and daily thereafter until discharge. According to the immediate post TAVR ECG, patients were divided into 2 groups, immediate and delayed new onset LBBB. Both groups were followed for the occurrence of PPI and mortality Results : Among patients who underwent TAVR, 296 (20.1%) developed new-onset LBBB, of whom, 282 were included the present study. LBBB occurred immediately after the procedure in 249 patients (88.3%) and was delayed in 33 patients (11.7%). Rates of both early PPI within 2 weeks as well as long term PPI and mortality were comparable between patients with immediate vs. delayed onset LBBB. In patients with immediate LBBB, QRS width correlated with a need for PPI, while in patients with delayed LBBB, PR prolongation of ≥ 115 ms differentiated between patients with and without PPI. Conclusions : The appearance of new onset post TAVR LBBB may be delayed in ~12% of patients. These patients exhibit similar rates of PPI need and mortality; however different ECG parameters signify high risk for PPI need among these patients. Left Bunder Branch Block transcatheter aortic valve replacement (TAVR) permanent pacemaker implantation (PPI) delayed immediate Figures Figure 1 Figure 2 Figure 3 Introduction Left bundle branch block (LBBB) is the most common conduction abnormality occurring after trans catheter aortic valve replacement (TAVR). 1 – 5 Multiple studies have examined its predictive value for the development of advanced atrioventricular block (AVB) and need for permanent pacemaker implantation (PPI), as well as its long-term effect on left ventricular function and patients’ overall survival. 6 , 7 Most commonly, new-onset TAVR related LBBB occurs during the procedure and is recorded immediately on the first post-TAVR ECG. 8 , 9 Nevertheless, few studies have shown that the appearance of post-TAVR new-onset LBBB may be delayed. Houthuizen et al reported 12% incidence of subacute LBBB, 10 defined as occurring more than 24 hours after TAVR, while Urena et al described an incidence of 6.5%, with delayed onset LBBB occurring in 4 out 61 cases of new-onset post-TAVR LBBB. 6 The above-mentioned studies focus was on the persistence of LBBB during hospitalization and during follow-up and its relation to prognosis. 6 , 7 , 10 Other studies demonstrated that post-TAVR conduction abnormalities are dynamic and may progress or regress during the first post procedural days. 1 , 11 , 12 Nevertheless, the characteristics and clinical significance of immediate versus delayed post TAVR new-onset LBBB have not been studied. The current study sought to define the incidence, characteristics, and clinical significance of immediate versus delayed post-TAVR new-onset LBBB. Methods Patient Population This study included patients who underwent TAVR between 2010 and 2022 and had new-onset LBBB documented on electrocardiogram (ECG). Patients were excluded if they had: (i) pre-existing bundle branch block (BBB) prior to TAVR; (ii) a history of prior TAVR or surgical aortic valve replacement (SAVR); (iii) a pre-existing permanent pacemaker; (iv) missing documentation of LBBB post-TAVR; or (v) newly developed right bundle branch block (RBBB) after the procedure. Clinical, procedural, electrocardiographic, and echocardiographic data were obtained through manual review of electronic medical records. The study protocol was approved by the institutional ethics committees, and the requirement for written informed consent was waived due to the retrospective nature of the analysis and the use of deidentified data. Collected baseline and post-procedure ECG parameters included: rhythm, electrical axis, PR interval, QRS morphology and duration. Post-TAVR ECGs were reviewed from the time of post procedure admission to the cardiac intensive care unit or cardiology department (first post-TAVR ECG) and daily thereafter until discharge. Patients were included if they had documented new-onset LBBB at any point during the index hospitalization. They were then stratified into two groups based on the timing of LBBB onset: immediate LBBB was defined as the documentation of a new post-TAVR LBBB on the first post-TAVR ECG, and delayed LBBB , when the first post-TAVR ECG demonstrated narrow QRS and LBBB was documented on subsequent ECGs during hospitalization. The incidence of in hospital AVB, alternating BBB, performance of electro-physiological study (EPS) and the need for PPI were recorded. Definitions of BBB and fascicular blocks followed the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society recommendations 13 and the 2021 European Society of Cardiology guidelines on cardiac pacing and resynchronization therapy. 3 Follow-Up Patients were followed for the need of PPI, including clinical indications, as well as all-cause mortality. For the analysis of PPI as an adverse event, only patients with a relevant clinical indication were included. These indications comprised complete or high-degree AVB, alternating BBB, or a PPI indication established by EPS. 3 Device implantation due to sick sinus syndrome (SSS), ventricular arrhythmias, or heart failure (i.e., implantable cardioverter defibrillator or cardiac resynchronization therapy implantation) were not considered TAVR related PPI. Follow-up was conducted via electronic health records and phone call when needed. Statistical Analysis Continuous variables were assessed for distribution using histograms and are reported as means with standard deviations. Categorical variables are presented as frequencies and percentages. Comparisons between groups (immediate and delayed LBBB post-TAVR) were made using the Chi-square or Fisher’s exact test for categorical variables, and the Mann–Whitney U test for continuous variables. Kaplan–Meier survival analyses were performed to estimate the cumulative incidence of all-cause mortality and PPI and log rank test was used to compare between the various groups. The area under the receiver-operating characteristic (ROC) curve was used to evaluate the discriminating ability of maximal Δ PR on the occurrence of PPI in patients with immediate and delayed post-TAVR LBBB. Maximal Youden index was applied to identify the optimal cutoff value. A two-sided p-value < 0.05 was considered statistically significant. All statistical analyses were conducted using IBM SPSS Statistics, version 29.0.2.0 (Chicago, IL, USA). Results Study Population Between May 2010 and December 2022, a total of 1469 TAVR procedures were performed at our institution, among which, 107 patients already had a permanent pacemaker in place and 62 had baseline BBB before the TAVR. Three hundred and nine (21%) patients developed new BBB following the procedure. Of these, the following were excluded; 13 developed RBBB, 5 7 had previous TAVR/ SAVR and underwent valve in valve procedure and 7 underwent TAVR for aortic insufficiency. Therefore, 282 patients were eligible for analysis in the current study. These were categorized based on the timing of new-onset LBBB detection: 249 patients (88.3%) as the immediate LBBB group and 33 (11.7%) as the delayed LBBB group. Of note, 1 (3%) patient from the delayed-LBBB group had axis change on his first post TAVR ECG before developing LBBB. Median follow-up was 3.4 years (IQR 2.1–5.2 years). As detailed in Table 1 , baseline clinical characteristics were comparable between patients with delayed versus immediate post TAVR LBBB. However, few procedural details were different; valve size was marginally larger (p = 0.058) and use of temporary pacemaker was lower in patients with delayed-onset post-TAVR LBBB (p < 0.001). Use of balloon-expandable vs. self-expandable valves were similar (p = 0.55). Eight (24%) patients from the delayed LBBB group had transient QRS widening during the TAVR, however their first post TAVR ECG demonstrated narrow QRS. Post procedurally rates of in hospital, AVB, PPI and death were comparable between the 2 groups, however, hospitalization duration was longer in patients with delayed post TAVR LBBB [7.7 days (IQR 3–9) versus 6.2 days (IQR 3–6), respectively, p = 0.014]. Table 1 Baseline Clinical Characteristics Immediate LBBB Delayed LBBB p Value (n = 249) (n = 33) Age (years) 80.58 ± 7.2 80.76 ± 7.9 0.656 Female sex (%) 125 (50.2) 18 (54.5) 0.639 BMI (Kg/m 2 ) 27.7 ± 5.1 29.5 ± 5.1 0.052 Diabetes Mellitus (%) 103 (41.4) 15 (45.5) 0.655 Hypertension (%) 214 (85.9) 29 (87.9) > 0.99 Hyperlipidemia (%) 178 (71.5) 27 (81.8) 0.211 Chronic Renal Failure (%) 55 (22.1) 4 (12.2) 0.186 Atrial Fib/Flutter (%) 65 (26.1) 13 (39.4) 0.109 Prior IHD (%) 128 (51.4) 16 (48.5) 0.752 Beta-blockers (%) 143 (57.4) 23 (69.7) 0.178 ACE inhibitors/ARB (%) 150 (60.2) 18 (54.5) 0.531 Amiodarone (%) 31 (12.4) 4 (12.1) > 0.99 LVEF (%) 55.6 ± 7.9 57.1 ± 6.1 0.371 Aortic valve area (cm 2 ) 0.63 ± 0.15 0.59 ± 0.14 0.122 Peak gradient (mmHg) 81.5 ± 25.2 81.3 ± 26.4 0.977 Mean gradient (mmHg) 48.2 ± 15.5 48.7 ± 17.1 0.907 Calcium score (HU) 2568 ± 1674.9 2467 ± 1435.2 0.898 Procedural characteristics Trans femoral access 247 (99.2) 33 (100.0) > 0.99 Valve mechanism (BEV/SEV) 107(43.0)/142(57.0) 16(48.5)/17(51.5) 0.548 Valve size 26.4 ± 2.4 27.4 ± 2.9 0.058 Transient CAVB during TAVR 14 (5.6) 1 (3.0) > 0.99 Transient QRS widening during TAVR 0 (0) 8 (24.2) < 0.001 Temporary pacemaker 185 (74.3) 10 (30.3)* < 0.001 In hospital post procedure events/ management EPS 29 (11.6) 6 (18.2) 0.269 CAVB or HDAVB during hospitalization 22 (8.8) 5 (15.2) 0.347 In hospital PPI 31 (12.4) 7 (21.2) 0.176 Days to in hospital PPI 3 (1–6) 3 (2–6) 0.97 Death in hospital 2 (0.8) 2 (6.1) 0.069 Hospitalization time (days), median (IQR) 6.2 (3–6) 7.7 (3–9) 0.014 AADs = anti arrhythmic drugs; ARB = angiotensin II receptor blocker; ACE = angiotensin converting enzyme; BEV = balloon-expandable valve; BMI = body mass index; CAVB = complete atrioventricular block; EPS = electrophysiological study; HDAVB = high-degree atrioventricular block; IHD = heart ischemic disease; LVEF = left ventricular ejection fraction, PPI = permanent pacemaker implantation; SEV = self-expandable valve; TAVR = Transcatheter aortic valve replacement. * 7 patients were left with temporary pacemaker immediately post TAVR due to: transient AVB (n = 1), transient QRS widening (n = 4), cardio pulmonary resuscitation during TAVR (n = 1), and junctional rhythm during TAVR (n = 1). Another 3 received temporary pacemaker post procedure due to development of delayed post TAVR LBBB. Electrocardiograms (ECGs) were available for all 282 patients, including baseline, daily post-procedural recordings, and ECGs performed prior to hospital discharge. Table 2 outlines the pre- and post-TAVR ECG parameter of the 2 patients’ groups. A significant difference was observed in pre-TAVR QRS axis distribution, with a higher proportion of patients in the immediate LBBB group exhibiting a normal axis compared to the delayed LBBB group [66.7% vs. 54.5%, respectively; p = 0.044]. The immediate LBBB group also demonstrated a trend toward longer pre-TAVR PR intervals compared to the delayed group [188.9 (IQR 160-212ms) vs. 174.1 (IQR 154-188ms); p = 0.056]. Table 2 Pre and post TAVR ECG parameters of patients with immediate and delayed LBBB Immediate LBBB Delayed LBBB p Value (n = 249) (n = 33) Pre TAVR ECG Sinus rhythm 228 (91.6) 27 (81.8) 0.106 QRS axis (N/L/R) 166 (66.7)/83 (33.3)/0 (0.0) 18 (54.5)/ 14 (42.4)/ 1(3.0) 0.044 PR duration* (ms) 188.9 ± 38.6 174.1 ± 27.3 0.056 QRS duration (ms) 92.8 ± 12.7 92.9 ± 11.8 0.811 Post TAVR ECG Sinus rhythm 227 (91.2) 27 (81.8) 0.115 QRS axis (N/L/R) 57 (22.9)/ 189 (75.9)/ 3 (1.2) 5 (15.2)/ 28 (84.8)/ 0 (0.0) 0.571 Axis change (%) 120 (48.2) 14 (42.4) 0.533 Post TAVR PR duration (ms) *,$ 202.9 ± 37.6 200.4 ± 49.9 0.427 Post TAVR QRS duration (ms) $ 145.3 ± 15.3 142.2 ± 14 0.329 Maximal PR duration (ms)* ,# 227.68 ± 42.7 239.5 ± 45.6 0.16 Maximal QRS duration (ms) # 149.9 ± 16.2 146.8 ± 16.2 0.392 Δ PR (ms)* 14.3 ± 34.5 23.8 ± 46.1 0.829 Maximal Δ PR* (ms) & 39.1 ± 34.4 65.5 ± 48.3 0.005 Δ QRS (ms) 52.4 ± 16.5 49.3 ± 15.3 0.276 Maximal Δ QRS (ms) & 57.06 ± 16.6 53.8 ± 15.9 0.292 Days to LBBB 0 1.88 (1-2.5) < 0.001 Day of maximal PR duration* 1.63 (0–3) 3.54 (2-4.75) < 0.001 Day of maximal QRS duration 0.88 (0–1) 2.58 (1-3.5) < 0.001 Persistent LBBB upon discharge^ 142 (57) 24 (72.7) 0.09 LBBB = left bundle branch block; N/L/R = normal/left/right; PPI = permanent pacemaker implantation; TAVR = transcatheter aortic valve replacement * Data not available for 25 patients with atrial fibrillation (20 with immediate LBBB and 5 with delayed LBBB) $ In first ECG documentation of LBBB after TAVR # Longest documented PR/QRS during hospital follow-up & Δ between maximal PR/QRS to pre-TAVR PR/QRS ^ Persistent to discharge or to in hospital pacemaker implantation or mortality. As per inclusion criteria (new-onset LBBB), QRS duration increased post-procedurally, from 92.8ms (IQR 82–101ms) to 145.3ms (IQR 134–155ms) in the immediate LBBB group and from 92.9ms (IQR 84–100ms) to 142.2ms (IQR 132–157ms) in the delayed LBBB group (p = 0.329). In addition, as expected, the median day of LBBB onset differed significantly between the groups, occurring on day 0 (same day as the TAVR) in the immediate group and on day 1.88 (IQR 1-2.5) in the delayed group (p < 0.001). The timing of maximal PR prolongation and QRS widening also differed, with earlier peaks in the immediate LBBB group compared to the delayed group: 1.63 (IQR 0–3) vs. 3.54 (IQR 2-4.75) days for PR interval and 0.88 (IQR 0–1) vs. 2.58 (IQR 1-2.5) days for QRS duration, respectively (p < 0.001 for both). The change in PR interval from baseline to maximum post-TAVR was significantly greater in the delayed LBBB group (65.5ms ± 48.3 vs. 39.1 ± 34.4ms; p = 0.005). Other ECG parameters did not differ significantly between the two groups. PPI and mortality during follow-up During the first-year post TAVR, 32 (12.8%) and 7 (21%) patients underwent PPI (p = 0.19) due to relevant indication from the immediate and delayed post-TAVR LBBB groups, respectively. All these PPIs occurred during the first 2 weeks post-TAVR except for 1 PPI from the immediate LBBB group that occurred 41 days post-TAVR. PPI indications during the first 2-weeks post TAVR, included AVB in 24 (77.4%) vs 5 (71.4%), alternating BBB in 3 (9.7%) vs 1 (14.3%) and EPS demonstrating prolonged HV > 70 ms in 4 (12.9%) vs 1 (14.3%), p = 0.93; in the immediate and delayed LBBB subgroups, respectively. Mortality events during this period of one year, occurred in 50 (20%) and 11 (33.3%), p = 0.11, from the immediate and delayed post TAVR LBBB groups, respectively. KM curves of 1- and 5-years follow-up, for PPI, mortality and the combined endpoint of PPI and mortality are presented in Fig. 1 and Supplementary Fig. 1, respectively. Patients in the delayed LBBB group had a nonsignificant worse outcomes during 1- and 5-years follow-up of both need for PPI and mortality. Predictors for PPI in patients with immediate vs. delayed post TAVR LBBB Table 3 and Supplementary Table 1 demonstrate separate comparisons for patients with immediate and delayed post-TAVR LBBB. In each patients’ group, a comparison is made between those with and without PPI within 2-weeks post-TAVR. In patients with immediate -onset LBBB, baseline, post procedural and maximal QRS width were significantly wider in patients who underwent PPI compared to those who did not. Maximal Δ PR was marginally longer in patients with PPI (p = 0.052). In addition, persistence of LBBB was more common among patients who underwent PPI. In contrast, in patients with delayed-onset LBBB, neither QRS width (baseline, post procedural and maximal QRS width), nor LBBB persistence to discharge, were significantly different between patients with and without PPI. Rather, baseline PR was shorter and maximal Δ PR was longer in patients with PPI compared to those without PPI. Of note, among patients with delayed-onset LBBB, PPI was more common among men compared to woman. An example of sequential ECG changes in a patient with post-TAVR delayed-onset LBBB is presented in Fig. 2 . Table 3 ECG parameters of patients with immediate and delayed LBBB with and without early PPI within 2 weeks Immediate LBBB p Value Delayed LBBB p Value (n = 247) * (n = 32) * No PPI (n = 216) PPI (n = 31) No PPI (n = 25) PPI (n = 7) Pre TAVR ECG Sinus Rhythm 199 (92.1) 27 (87.1) 0.313 21 (84.0) 5 (71.4) 0.59 QRS axis (N/L/R) 150(69.4)/66(30.6)/0(0) 15(48.4)/16(51.6)/0(0) 0.02 14 (56)/11(44)/0(0) 3(42.9)/3(42.9)/1(14.3) 0.292 PR duration ** (ms) 189.1 ± 38.9 189.6 ± 37.6 0.613 180.8 ± 26.7 150.8 ± 14.3 0.019 QRS duration (ms) 92.31 ± 12.8 97.16 ± 11.3 0.048 94.32 ± 11.9 89.43 ± 11.5 0.324 Post TAVR ECG Sinus rhythm 197 (91.2) 28 (90.3) 0.745 21 (84.0) 5 (71.4) 0.59 QRS axis (N/L/R) 51(23.6)/163(75.5)/2(0.9) 6(19.4)/25(80.6)/0(0.0) 0.196 3(12)/22(88)/0(0) 2(28.6)/5(71.4)/0(0) 0.296 Axis change (%) 105 (48.6) 14 (45.2) 0.719 11 (44) 2 (28.6) 0.671 Post TAVR PR duration (ms) **,$ 201.7 ± 37.4 212.2 ± 39.6 0.174 197.8 ± 43.7 219.2 ± 76.0 0.569 Post TAVR QRS duration (ms) $ 144.5 ± 15.2 150.9 ± 15.0 0.021 141.3 ± 14.3 143.2 ± 13.0 0.688 Maximal PR duration (ms) **,# 226.4 ± 43.3 238.4 ± 36.2 0.136 235.9 ± 46.1 265.0 ± 26.8 0.195 Maximal QRS duration (ms) # 148.7 ± 15.8 158.2 ± 16.8 0.003 145.08 ± 16.2 151.5 ± 17.2 0.503 Δ PR (ms) ** 13.1 ± 34.7 22.5 ± 32.6 0.206 16.9 ± 38.2 63 ± 74.5 0.496 Maximal Δ PR (ms) **,& 37.8 ± 34.6 49.7 ± 32.6 0.052 55.09 ± 43.4 120 ± 27.2 0.003 Δ QRS (ms) 52.2 ± 16.5 53.7 ± 15.9 0.648 47.0 ± 13.8 53.8 ± 18.4 0.755 Maximal Δ QRS (ms) & 56.4 ± 16.5 61.09 ± 16.9 0.22 50.7 ± 14.9 62.1 ± 16.5 0.191 Days to LBBB 0 0 > 0.99 1 (1-2.5) 2 (1–3) 0.72 Day of maximal PR duration ** 0 (0–3) 2 (0–4) 0.19 4 (2–5) 3 (1.5-3) 0.25 Day of maximal QRS duration 0 (0–1) 1 (0–2) 0.2 2 (1–5) 3 (2–3) 0.97 Persistent LBBB upon discharge^ 112 (51.8) 30 (96.7) < 0.001 17 (68) 7 (100) 0.15 LBBB = left bundle branch block; N/L/R = normal/left/right; PPI = permanent pacemaker implantation; TAVR = transcatheter aortic valve replacement * 2 patients from the immediate and 1 from the delayed LBBB groups, who died on days 0, 1 and 4 post TAVR were excluded from this analysis. ** Data not available for 25 patients with atrial fibrillation (20 with immediate LBBB and 5 with delayed LBBB) $ In first ECG documentation of LBBB after TAVR # Longest documented PR/QRS during hospital follow-up & Δ between maximal PR/QRS to pre-TAVR PR/QRS ^ Persistent to discharge or to in hospital pacemaker implantation or mortality. ROC analysis was conducted to define the best cutoff of maximal Δ PR differentiating the need for PPI among patients with delayed and with immediate-onset post TAVR LBBB. An area under the curve of 0.92 (95% CI 0.79–1.05, p < 0.001) and 0.62 (95% CI 0.52–0.72, p = 0.02), respectively was found (Fig. 3 ). Among patients with delayed-onset post-TAVR LBBB, a cutoff of maximal Δ PR of 115 ms had a specificity of 91% and a sensitivity of 80% in predicting the need for PPI. While, in patients with immediate post TAVR LBBB, a cutoff of maximal Δ PR of 20.5 ms had a specificity of 34% and a sensitivity of 93% in predicting a need for PPI. Discussion Main findings Our study which was conducted on a cohort of 1469 consecutive TAVR patients exhibited, in accordance with previous reports, 1–3, 14 that post-TAVR new onset LBBB occurs in ~ 20% of patients. However, it demonstrated that in 11.7% of patients with new-onset LBBB, appearance of LBBB may be delayed and not manifest immediately post TAVR. The clinical consequences of delayed compared to immediate post-TAVR LBBB were shown for the first time, to be comparable, with similar rates of PPI need and mortality, both early and during long term follow-up. Nevertheless, different ECG abnormalities correlated with a need for PPI, while in patients with immediate post TAVR LBBB, QRS width was the dominant discriminating factor, in patients with delayed post TAVR LBBB, the maximal Δ PR differentiated between patients with and without need for PPI. In the delayed post TAVR LBBB group, a cutoff of Δ PR of 115 ms had a sensitivity and specificity of 80% and 91%, respectively for need of PPI. Previous studies Most studies on post TAVR new onset LBBB focused on either, the best approach to risk stratify these patients, 1–3, 15 or on LBBB persistence in relation to clinical endpoints, including PPI need, LV function deterioration, and mortality. 2 , 6 , 7 , 10 , 14 Few of these studies showed that the appearance of post TAVR new onset LBBB may be delayed in 6.5–15% of patients. 6 , 10 , 16 , 17 Massoullie et al studied a cohort of 183 patients with post TAVR new onset LBBB. 16 In ~ 15% the appearance of LBBB was delayed (median 2 days, range 1–3 days post TAVR). Urena et al studied, 61 cases of new-onset post-TAVR LBBB, using balloon- expandable valve. Fifty-seven (93.4%) new-onset LBBB cases were seen immediately on the first post-TAVR ECG, however, in 4 (6.5%), the LBBB appearance was not immediate. 6 Of note, in only 1 of these 4 cases, no conduction abnormality was seen on the first post-TAVR ECG. The other 3 had either, new left anterior hemiblock or incomplete LBBB on their first ECG before developing LBBB. Houthuizen et al reported an incidence of 12% (21 cases out of 175 new onset post TAVR LBBB) of subacute LBBB, defined as occurring more than 24 hours post TAVR. 10 Finally, Testa et al reported an incidence of 10.1% delayed LBBB (40 out of 394 new onset LBBB cases), based on immediate and predischarge post TAVR ECGs. 17 Of note, rate of LBBB persistence to discharge in patients with delayed onset LBBB, was either not specifically reported, 6, 16 or was lower in 1 study reaching 43% in the delayed LBBB group compared to 65% in the immediate LBBB group. 10 In the study by Testa et al, LBBB persistence to discharge was 100% by definition, as only the immediate and predischarge ECGs were analyzed. 17 None of these studies defined the specific characteristics, risk factors for PPI need and prognosis of the delayed post TAVR LBBB patient population. Possible mechanism of delayed onset LBBB and clinical implications TAVR related insult to the conduction system may occur as a consequence of direct trauma during different stages of the procedure, causing immediately manifested conduction abnormality. 1 , 8 Post procedurally, continued mechanical pressure, valve self-expansion and development of edema inflammation and fibrosis may further compromise the conduction system 1 manifesting as further worsening of an immediately manifested conduction abnormality or development of new delayed conduction abnormality. Interestingly, in the current study, patients with delayed onset LBBB could be stratified into high and low likelihood of PPI need within 2 weeks post TAVR, using maximal Δ PR which was mostly > 115 ms in those who underwent PPI. It is possible that insult to different parts along the conduction system accounts for the appearance of delayed LBBB with or without continued conduction worsening and PPI need. In those with delayed LBBB and no significant PR change the insult may be confined to the LBB while in those with significant PR prolongation the insult may involve the His bundle and fibers that are destined to form the LBB or involve both bundles with more pronounced damage to the LBB and thus manifests with both LBBB and PR prolongation with increased risk for developing AV block. The finding that maximal Δ PR was longer in patients with delayed compared to immediate LBBB, regardless of PPI (Table 2 ), suggests that as a group the average insult to the conduction system was more proximal manifesting with both PR prolongation and LBBB. Clinically, the current study suggests that patients with delayed LBBB and especially those with significant PR interval prolongation should be monitored for longer times, with extended hospitalization and possibly even monitored post discharge. In addition, EPS maybe be used as per treating physician practice. 15 , 16 Notably, while we have previously published that PR prolongation per se in patients with narrow QRS, is not predictive of the need for PPI, 4 its combination with LBBB and especially delayed LBBB may warrant further attention and prolonged monitoring. Limitations An inherent study limitation is related to its observational retrospective design. ECGs were performed daily and were meticulously analyzed. However, continuous telemetry data, both during and post TAVR, was not available for analysis and therefore we cannot rule out the occurrence of few transient LBBB or AVB cases that went unnoticed. Despite analyzing a large database of almost 1500 TAVR cases, the ultimate number of patients with delayed LBBB and especially those who needed PPI was relatively small, precluding performance of multivariate analysis, and enabling type II error due to small numbers (notably, there was a nonsignificant trend to worse outcomes in the delayed LBBB group). Further larger studies may clarify this point. Finally, according to the study design the cause of delayed versus immediate post TAVR LBBB was not explored, however, our main goal was to describe the phenomenon of delayed LBBB and possible risk factors for PPI once it occurred. Conclusion Around 12% of post-TAVR new onset LBBB cases are delayed and not seen immediately after the procedure. Prognosis of these patients, in terms of PPI need and mortality, is not significantly different from patients with immediate post TAVR-LBBB. However, ECG parameters that correspond to higher PPI risk are different. While QRS duration correlates with PPI need in patients with immediate LBBB, Δ PR > 115 ms correlates with PPI need in patients with delayed LBBB. Abbreviations AVB = atrio-ventricular block ECG = electrocardiogram EPS = electrophysiological study LBBB = left bundle branch block PPI = permanent pacemaker implantation RBBB = right bundle branch block ROC = receiver operator characteristics SAVR = surgical aortic valve replacement SSS = sick sinus syndrome TAVR = transcatheter aortic valve replacement Declarations Disclosures: YM : Consultant for Edwards Lifesciences (Irvine, California); DD : Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); MG advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest. Competing Interests YM: Consultant for Edwards Lifesciences (Irvine, California); DD: Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); MG advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest. Funding: Eisenberg R&D authority, Shaare Zedek Medical Center. Author Contribution MS, OTB and YM wrote the main manuscript and prepared the figures and Tables. MZ and NP helped with data acquisition. All authors reviewed the manuscript. Data Availability The data underlying this article will be shared on reasonable request to the corresponding author. References Auffret V, Puri R, Urena M, et al. Conduction Disturbances After Transcatheter Aortic Valve Replacement: Current Status and Future Perspectives. Circulation Sep. 2017;12:136:1049–69. Rodes-Cabau J, Ellenbogen KA, Krahn AD, et al. Management of Conduction Disturbances Associated With Transcatheter Aortic Valve Replacement: JACC Scientific Expert Panel. J Am Coll Cardiol Aug. 2019;27:74:1086–106. Glikson M, Nielsen JC, Kronborg MB, et al. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. Europace Jan. 2022;4:24:71–164. Perel N, Tovia-Brodie O, Schnur A, et al. Post-transcatheter aortic valve implantation isolated PR prolongation: incidence and clinical significance. Europace Dec. 2023;28:26. Michowitz Y, Yagel O, Shrem M et al. New-Onset RBBB After Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation. JACC Clin Electrophysiol Jul 29 2025. Urena M, Mok M, Serra V, et al. Predictive factors and long-term clinical consequences of persistent left bundle branch block following transcatheter aortic valve implantation with a balloon-expandable valve. J Am Coll Cardiol Oct. 2012;30:60:1743–52. Urena M, Webb JG, Cheema A, et al. Impact of new-onset persistent left bundle branch block on late clinical outcomes in patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve. JACC Cardiovasc Interv Feb. 2014;7:128–36. Nuis RJ, Van Mieghem NM, Schultz CJ, et al. Timing and potential mechanisms of new conduction abnormalities during the implantation of the Medtronic CoreValve System in patients with aortic stenosis. Eur Heart J Aug. 2011;32:2067–74. Reiter C, Lambert T, Kellermair J, et al. Intraprocedural dynamics of cardiac conduction during transcatheter aortic valve implantation: Assessment by simultaneous electrophysiological testing. Heart Rhythm Mar. 2021;18:419–25. Houthuizen P, van der Boon RM, Urena M, et al. Occurrence, fate and consequences of ventricular conduction abnormalities after transcatheter aortic valve implantation. EuroIntervention Feb. 2014;9:1142–50. van Gils L, Baart S, Kroon H, et al. Conduction dynamics after transcatheter aortic valve implantation and implications for permanent pacemaker implantation and early discharge: the CONDUCT-study. Europace Dec. 2018;1:20:1981–8. Chua AP, Myagmardorj R, Nabeta T, et al. Conduction Disorders After Transcatheter Aortic Valve Implantation: Evolution Over Time and Association With Long-Term Outcomes. Struct Heart May. 2025;9:100428. Surawicz B, Childers R, Deal BJ, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol Mar. 2009;17:53:976–81. Faroux L, Chen S, Muntane-Carol G, et al. Clinical impact of conduction disturbances in transcatheter aortic valve replacement recipients: a systematic review and meta-analysis. Eur Heart J Aug. 2020;1:41:2771–81. Tovia-Brodie O, Ben-Haim Y, Joffe E, et al. The value of electrophysiologic study in decision-making regarding the need for pacemaker implantation after TAVI. J Interv Card Electrophysiol Mar. 2017;48:121–30. Massoullie G, Ploux S, Souteyrand G, et al. Incidence and management of atrioventricular conduction disorders in new-onset left bundle branch block after TAVI: A prospective multicenter study. Heart Rhythm May. 2023;20:699–706. Testa L, Latib A, De Marco F, et al. Clinical impact of persistent left bundle-branch block after transcatheter aortic valve implantation with CoreValve Revalving System. Circulation Mar. 2013;26:127:1300–7. Additional Declarations Competing interest reported. YM: Consultant for Edwards Lifesciences (Irvine, California); DD: Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); MG advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest. Supplementary Files supptable.docx SupplementaryFigure.pptx Cite Share Download PDF Status: Published Journal Publication published 19 Feb, 2026 Read the published version in Journal of Interventional Cardiac Electrophysiology → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8121179","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":551862202,"identity":"5d3ea253-56eb-43f8-a3a7-c75840dea4ba","order_by":0,"name":"Maayan Shrem","email":"","orcid":"","institution":"Shaare Zedek Medical Center","correspondingAuthor":false,"prefix":"","firstName":"Maayan","middleName":"","lastName":"Shrem","suffix":""},{"id":551862203,"identity":"73d87c1d-b6a0-4b6b-8bd9-b27885410848","order_by":1,"name":"Oholi Tovia-Brodie","email":"","orcid":"","institution":"Shaare Zedek Medical 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08:40:01","extension":"xml","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100475,"visible":true,"origin":"","legend":"","description":"","filename":"d61411191ab64c7591532757478d4b8d1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/803103fc3f79980fe929500a.xml"},{"id":97130570,"identity":"ba8fc09e-72e1-4e51-9ffb-08b639c0c742","added_by":"auto","created_at":"2025-12-01 08:40:04","extension":"html","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":108071,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/f6226407e26b543ec773b1a0.html"},{"id":97130568,"identity":"8097f208-3ce3-46b2-866b-37a1c0e68515","added_by":"auto","created_at":"2025-12-01 08:40:03","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":43026,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier curves for \u003cstrong\u003eA\u003c/strong\u003e-permanent pacemaker implantation, \u003cstrong\u003eB\u003c/strong\u003e-Mortality, \u003cstrong\u003eC\u003c/strong\u003e-combined endpoint of PPI and mortality during 1-year follow-up. A nonsignificant worst outcome is shown in all curves for patients with delayed (blue line) compared to immediate (red line) post TAVR LBBB.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/dd3c3919872b85ca53f9acda.png"},{"id":97130599,"identity":"9a4c7480-53c3-40f1-96e0-ea816483a182","added_by":"auto","created_at":"2025-12-01 08:40:07","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2719788,"visible":true,"origin":"","legend":"\u003cp\u003eSerial ECGs of an exemplary patient with delayed LBBB. A – pre-TAVR baseline ECG, PR 160ms and narrow QRS are shown. B – Immediate post-TAVR ECG showing PR 190ms with narrow QRS. C – ECG post TAVR showing PR prolongation to 300ms with narrow QRS. D – First documented LBBB post-TAVR, PR 390ms (ΔPR=230ms) and QRS 135ms with LBBB morphology. E - 24h Holter monitoring demonstrating 2:1 AVB, blue arrows point to P waves.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/c9686766fd5b4e4372d6a9f9.jpg"},{"id":97130592,"identity":"9b15b698-4b97-402f-96c6-236cd01264a5","added_by":"auto","created_at":"2025-12-01 08:40:06","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":105638,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operating characteristic curve analysis of maximal ΔPR as a predictor of permanent pacemaker implantation among patients with \u003cstrong\u003eA\u003c/strong\u003e- delayed-onset post TAVR LBBB and \u003cstrong\u003eB\u003c/strong\u003e- immediate-onset post TAVR LBBB. An area under the curve of 0.92 (95% CI 0.79-1.05, p\u0026lt;0.001) and 0.62 (95% CI 0.52-0.72, p=0.02), in patients with delayed and immediate post TAVR LBBB respectively, was found. The arrow indicates optimal cutoff point for sensitivity and specificity among patients with delayed post-TAVR LBBB (see text).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/cf74a2f7c588bf33b6ca4660.png"},{"id":103251632,"identity":"466b69b4-2a80-4d56-863c-9046bd2531c1","added_by":"auto","created_at":"2026-02-23 16:11:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3874124,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/1ca08f1b-901d-450c-8bea-14e267ae3ffa.pdf"},{"id":97130619,"identity":"27593963-02dc-4f44-999b-68f1ce5a2b8e","added_by":"auto","created_at":"2025-12-01 08:40:11","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":20687,"visible":true,"origin":"","legend":"","description":"","filename":"supptable.docx","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/ad105ecef200ad35a8d0db4f.docx"},{"id":97130578,"identity":"0819babd-8b59-486e-9993-8465d6133dc3","added_by":"auto","created_at":"2025-12-01 08:40:04","extension":"pptx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":114736,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFigure.pptx","url":"https://assets-eu.researchsquare.com/files/rs-8121179/v1/94099234e531283dcccd12f2.pptx"}],"financialInterests":"Competing interest reported. YM: Consultant for Edwards Lifesciences (Irvine, California); DD: Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); MG advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest.","formattedTitle":"Immediate vs Delayed Left Bundle Branch Block after Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLeft bundle branch block (LBBB) is the most common conduction abnormality occurring after trans catheter aortic valve replacement (TAVR).\u003csup\u003e\u003cspan additionalcitationids=\"CR2 CR3 CR4\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e Multiple studies have examined its predictive value for the development of advanced atrioventricular block (AVB) and need for permanent pacemaker implantation (PPI), as well as its long-term effect on left ventricular function and patients\u0026rsquo; overall survival.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eMost commonly, new-onset TAVR related LBBB occurs during the procedure and is recorded immediately on the first post-TAVR ECG.\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e Nevertheless, few studies have shown that the appearance of post-TAVR new-onset LBBB may be delayed. Houthuizen et al reported 12% incidence of subacute LBBB,\u003csup\u003e10\u003c/sup\u003e defined as occurring more than 24 hours after TAVR, while Urena et al described an incidence of 6.5%, with delayed onset LBBB occurring in 4 out 61 cases of new-onset post-TAVR LBBB.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eThe above-mentioned studies focus was on the persistence of LBBB during hospitalization and during follow-up and its relation to prognosis.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e Other studies demonstrated that post-TAVR conduction abnormalities are dynamic and may progress or regress during the first post procedural days.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e Nevertheless, the characteristics and clinical significance of immediate versus delayed post TAVR new-onset LBBB have not been studied. The current study sought to define the incidence, characteristics, and clinical significance of immediate versus delayed post-TAVR new-onset LBBB.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003ePatient Population\u003c/h2\u003e\u003cp\u003eThis study included patients who underwent TAVR between 2010 and 2022 and had new-onset LBBB documented on electrocardiogram (ECG). Patients were excluded if they had: (i) pre-existing bundle branch block (BBB) prior to TAVR; (ii) a history of prior TAVR or surgical aortic valve replacement (SAVR); (iii) a pre-existing permanent pacemaker; (iv) missing documentation of LBBB post-TAVR; or (v) newly developed right bundle branch block (RBBB) after the procedure.\u003c/p\u003e\u003cp\u003eClinical, procedural, electrocardiographic, and echocardiographic data were obtained through manual review of electronic medical records. The study protocol was approved by the institutional ethics committees, and the requirement for written informed consent was waived due to the retrospective nature of the analysis and the use of deidentified data.\u003c/p\u003e\u003cp\u003eCollected baseline and post-procedure ECG parameters included: rhythm, electrical axis, PR interval, QRS morphology and duration. Post-TAVR ECGs were reviewed from the time of post procedure admission to the cardiac intensive care unit or cardiology department (first post-TAVR ECG) and daily thereafter until discharge. Patients were included if they had documented new-onset LBBB at any point during the index hospitalization. They were then stratified into two groups based on the timing of LBBB onset: \u003cb\u003eimmediate LBBB\u003c/b\u003e was defined as the documentation of a new post-TAVR LBBB on the first post-TAVR ECG, and \u003cb\u003edelayed LBBB\u003c/b\u003e, when the first post-TAVR ECG demonstrated narrow QRS and LBBB was documented on subsequent ECGs during hospitalization.\u003c/p\u003e\u003cp\u003eThe incidence of in hospital AVB, alternating BBB, performance of electro-physiological study (EPS) and the need for PPI were recorded. Definitions of BBB and fascicular blocks followed the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society recommendations\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e and the 2021 European Society of Cardiology guidelines on cardiac pacing and resynchronization therapy.\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eFollow-Up\u003c/h3\u003e\n\u003cp\u003ePatients were followed for the need of PPI, including clinical indications, as well as all-cause mortality. For the analysis of PPI as an adverse event, only patients with a relevant clinical indication were included. These indications comprised complete or high-degree AVB, alternating BBB, or a PPI indication established by EPS.\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e Device implantation due to sick sinus syndrome (SSS), ventricular arrhythmias, or heart failure (i.e., implantable cardioverter defibrillator or cardiac resynchronization therapy implantation) were not considered TAVR related PPI. Follow-up was conducted via electronic health records and phone call when needed.\u003c/p\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eContinuous variables were assessed for distribution using histograms and are reported as means with standard deviations. Categorical variables are presented as frequencies and percentages. Comparisons between groups (immediate and delayed LBBB post-TAVR) were made using the Chi-square or Fisher\u0026rsquo;s exact test for categorical variables, and the Mann\u0026ndash;Whitney U test for continuous variables.\u003c/p\u003e\u003cp\u003eKaplan\u0026ndash;Meier survival analyses were performed to estimate the cumulative incidence of all-cause mortality and PPI and log rank test was used to compare between the various groups. The area under the receiver-operating characteristic (ROC) curve was used to evaluate the discriminating ability of maximal Δ PR on the occurrence of PPI in patients with immediate and delayed post-TAVR LBBB. Maximal Youden index was applied to identify the optimal cutoff value. A two-sided p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant. All statistical analyses were conducted using IBM SPSS Statistics, version 29.0.2.0 (Chicago, IL, USA).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eStudy Population\u003c/h2\u003e\u003cp\u003eBetween May 2010 and December 2022, a total of 1469 TAVR procedures were performed at our institution, among which, 107 patients already had a permanent pacemaker in place and 62 had baseline BBB before the TAVR. Three hundred and nine (21%) patients developed new BBB following the procedure. Of these, the following were excluded; 13 developed RBBB,\u003csup\u003e5\u003c/sup\u003e 7 had previous TAVR/ SAVR and underwent valve in valve procedure and 7 underwent TAVR for aortic insufficiency. Therefore, 282 patients were eligible for analysis in the current study. These were categorized based on the timing of new-onset LBBB detection: 249 patients (88.3%) as the immediate LBBB group and 33 (11.7%) as the delayed LBBB group. Of note, 1 (3%) patient from the delayed-LBBB group had axis change on his first post TAVR ECG before developing LBBB. Median follow-up was 3.4 years (IQR 2.1\u0026ndash;5.2 years).\u003c/p\u003e\u003cp\u003eAs detailed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, baseline clinical characteristics were comparable between patients with delayed versus immediate post TAVR LBBB. However, few procedural details were different; valve size was marginally larger (p\u0026thinsp;=\u0026thinsp;0.058) and use of temporary pacemaker was lower in patients with delayed-onset post-TAVR LBBB (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Use of balloon-expandable vs. self-expandable valves were similar (p\u0026thinsp;=\u0026thinsp;0.55). Eight (24%) patients from the delayed LBBB group had transient QRS widening during the TAVR, however their first post TAVR ECG demonstrated narrow QRS. Post procedurally rates of in hospital, AVB, PPI and death were comparable between the 2 groups, however, hospitalization duration was longer in patients with delayed post TAVR LBBB [7.7 days (IQR 3\u0026ndash;9) versus 6.2 days (IQR 3\u0026ndash;6), respectively, p\u0026thinsp;=\u0026thinsp;0.014].\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline Clinical Characteristics\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eImmediate LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDelayed LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;249)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;33)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e80.58\u0026thinsp;\u0026plusmn;\u0026thinsp;7.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e80.76\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.656\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale sex (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e125 (50.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (54.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.639\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (Kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.052\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes Mellitus (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e103 (41.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15 (45.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.655\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e214 (85.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e29 (87.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHyperlipidemia (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e178 (71.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27 (81.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.211\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eChronic Renal Failure (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55 (22.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (12.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.186\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAtrial Fib/Flutter (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e65 (26.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13 (39.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.109\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrior IHD (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e128 (51.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16 (48.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.752\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBeta-blockers (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e143 (57.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23 (69.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.178\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eACE inhibitors/ARB (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e150 (60.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (54.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.531\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAmiodarone (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e31 (12.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (12.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLVEF (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.6\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e57.1\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.371\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAortic valve area (cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.122\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeak gradient (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e81.5\u0026thinsp;\u0026plusmn;\u0026thinsp;25.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e81.3\u0026thinsp;\u0026plusmn;\u0026thinsp;26.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.977\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean gradient (mmHg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e48.2\u0026thinsp;\u0026plusmn;\u0026thinsp;15.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e48.7\u0026thinsp;\u0026plusmn;\u0026thinsp;17.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.907\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCalcium score (HU)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2568\u0026thinsp;\u0026plusmn;\u0026thinsp;1674.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2467\u0026thinsp;\u0026plusmn;\u0026thinsp;1435.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.898\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eProcedural characteristics\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTrans femoral access\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e247 (99.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33 (100.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eValve mechanism (BEV/SEV)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e107(43.0)/142(57.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e16(48.5)/17(51.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.548\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eValve size\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e26.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.058\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTransient CAVB during TAVR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14 (5.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (3.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTransient QRS widening during TAVR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 (24.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTemporary pacemaker\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e185 (74.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 (30.3)*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003e\u003cb\u003eIn hospital post procedure events/ management\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEPS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29 (11.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (18.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.269\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCAVB or HDAVB during hospitalization\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22 (8.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (15.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.347\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIn hospital PPI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e31 (12.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7 (21.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.176\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDays to in hospital PPI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (1\u0026ndash;6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (2\u0026ndash;6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.97\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDeath in hospital\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (0.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (6.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.069\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHospitalization time (days), median (IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.2 (3\u0026ndash;6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.7 (3\u0026ndash;9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eAADs\u0026thinsp;=\u0026thinsp;anti arrhythmic drugs; ARB\u0026thinsp;=\u0026thinsp;angiotensin II receptor blocker; ACE\u0026thinsp;=\u0026thinsp;angiotensin converting enzyme; BEV\u0026thinsp;=\u0026thinsp;balloon-expandable valve; BMI\u0026thinsp;=\u0026thinsp;body mass index; CAVB\u0026thinsp;=\u0026thinsp;complete atrioventricular block; EPS\u0026thinsp;=\u0026thinsp;electrophysiological study; HDAVB\u0026thinsp;=\u0026thinsp;high-degree atrioventricular block; IHD\u0026thinsp;=\u0026thinsp;heart ischemic disease; LVEF\u0026thinsp;=\u0026thinsp;left ventricular ejection fraction, PPI\u0026thinsp;=\u0026thinsp;permanent pacemaker implantation; SEV\u0026thinsp;=\u0026thinsp;self-expandable valve; TAVR\u0026thinsp;=\u0026thinsp;Transcatheter aortic valve replacement.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e* 7 patients were left with temporary pacemaker immediately post TAVR due to: transient AVB (n\u0026thinsp;=\u0026thinsp;1), transient QRS widening (n\u0026thinsp;=\u0026thinsp;4), cardio pulmonary resuscitation during TAVR (n\u0026thinsp;=\u0026thinsp;1), and junctional rhythm during TAVR (n\u0026thinsp;=\u0026thinsp;1). Another 3 received temporary pacemaker post procedure due to development of delayed post TAVR LBBB.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eElectrocardiograms (ECGs) were available for all 282 patients, including baseline, daily post-procedural recordings, and ECGs performed prior to hospital discharge.\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e outlines the pre- and post-TAVR ECG parameter of the 2 patients\u0026rsquo; groups. A significant difference was observed in pre-TAVR QRS axis distribution, with a higher proportion of patients in the immediate LBBB group exhibiting a normal axis compared to the delayed LBBB group [66.7% vs. 54.5%, respectively; p\u0026thinsp;=\u0026thinsp;0.044]. The immediate LBBB group also demonstrated a trend toward longer pre-TAVR PR intervals compared to the delayed group [188.9 (IQR 160-212ms) vs. 174.1 (IQR 154-188ms); p\u0026thinsp;=\u0026thinsp;0.056].\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePre and post TAVR ECG parameters of patients with immediate and delayed LBBB\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eImmediate LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eDelayed LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;249)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;33)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePre TAVR ECG\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSinus rhythm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e228 (91.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e27 (81.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.106\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS axis (N/L/R)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e166 (66.7)/83 (33.3)/0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e18 (54.5)/ 14 (42.4)/ 1(3.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.044\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePR duration* (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e188.9\u0026thinsp;\u0026plusmn;\u0026thinsp;38.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e174.1\u0026thinsp;\u0026plusmn;\u0026thinsp;27.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.056\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS duration (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e92.8\u0026thinsp;\u0026plusmn;\u0026thinsp;12.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e92.9\u0026thinsp;\u0026plusmn;\u0026thinsp;11.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.811\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePost TAVR ECG\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSinus rhythm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e227 (91.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e27 (81.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.115\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS axis (N/L/R)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57 (22.9)/ 189 (75.9)/ 3 (1.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5 (15.2)/ 28 (84.8)/ 0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.571\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAxis change (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e120 (48.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e14 (42.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.533\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost TAVR PR duration (ms)\u003csup\u003e*,$\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e202.9\u0026thinsp;\u0026plusmn;\u0026thinsp;37.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e200.4\u0026thinsp;\u0026plusmn;\u0026thinsp;49.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.427\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost TAVR QRS duration (ms)\u003csup\u003e$\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e145.3\u0026thinsp;\u0026plusmn;\u0026thinsp;15.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e142.2\u0026thinsp;\u0026plusmn;\u0026thinsp;14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.329\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal PR duration (ms)*\u003csup\u003e,#\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e227.68\u0026thinsp;\u0026plusmn;\u0026thinsp;42.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e239.5\u0026thinsp;\u0026plusmn;\u0026thinsp;45.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.16\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal QRS duration (ms)\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e149.9\u0026thinsp;\u0026plusmn;\u0026thinsp;16.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e146.8\u0026thinsp;\u0026plusmn;\u0026thinsp;16.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.392\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eΔ PR (ms)*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14.3\u0026thinsp;\u0026plusmn;\u0026thinsp;34.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e23.8\u0026thinsp;\u0026plusmn;\u0026thinsp;46.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.829\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal Δ PR* (ms)\u003csup\u003e\u0026amp;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e39.1\u0026thinsp;\u0026plusmn;\u0026thinsp;34.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e65.5\u0026thinsp;\u0026plusmn;\u0026thinsp;48.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eΔ QRS (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e52.4\u0026thinsp;\u0026plusmn;\u0026thinsp;16.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e49.3\u0026thinsp;\u0026plusmn;\u0026thinsp;15.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.276\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal Δ QRS (ms)\u003csup\u003e\u0026amp;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57.06\u0026thinsp;\u0026plusmn;\u0026thinsp;16.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e53.8\u0026thinsp;\u0026plusmn;\u0026thinsp;15.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.292\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDays to LBBB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.88 (1-2.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDay of maximal PR duration*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.63 (0\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3.54 (2-4.75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDay of maximal QRS duration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.88 (0\u0026ndash;1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.58 (1-3.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePersistent LBBB upon discharge^\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e142 (57)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e24 (72.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.09\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eLBBB\u0026thinsp;=\u0026thinsp;left bundle branch block; N/L/R\u0026thinsp;=\u0026thinsp;normal/left/right; PPI\u0026thinsp;=\u0026thinsp;permanent pacemaker implantation; TAVR\u0026thinsp;=\u0026thinsp;transcatheter aortic valve replacement\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e* Data not available for 25 patients with atrial fibrillation (20 with immediate LBBB and 5 with delayed LBBB)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e$\u003c/sup\u003e In first ECG documentation of LBBB after TAVR\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e#\u003c/sup\u003e Longest documented PR/QRS during hospital follow-up\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003csup\u003e\u0026amp;\u003c/sup\u003e Δ between maximal PR/QRS to pre-TAVR PR/QRS\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e^ Persistent to discharge or to in hospital pacemaker implantation or mortality.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAs per inclusion criteria (new-onset LBBB), QRS duration increased post-procedurally, from 92.8ms (IQR 82\u0026ndash;101ms) to 145.3ms (IQR 134\u0026ndash;155ms) in the immediate LBBB group and from 92.9ms (IQR 84\u0026ndash;100ms) to 142.2ms (IQR 132\u0026ndash;157ms) in the delayed LBBB group (p\u0026thinsp;=\u0026thinsp;0.329). In addition, as expected, the median day of LBBB onset differed significantly between the groups, occurring on day 0 (same day as the TAVR) in the immediate group and on day 1.88 (IQR 1-2.5) in the delayed group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003cp\u003eThe timing of maximal PR prolongation and QRS widening also differed, with earlier peaks in the immediate LBBB group compared to the delayed group: 1.63 (IQR 0\u0026ndash;3) vs. 3.54 (IQR 2-4.75) days for PR interval and 0.88 (IQR 0\u0026ndash;1) vs. 2.58 (IQR 1-2.5) days for QRS duration, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 for both). The change in PR interval from baseline to maximum post-TAVR was significantly greater in the delayed LBBB group (65.5ms\u0026thinsp;\u0026plusmn;\u0026thinsp;48.3 vs. 39.1\u0026thinsp;\u0026plusmn;\u0026thinsp;34.4ms; p\u0026thinsp;=\u0026thinsp;0.005). Other ECG parameters did not differ significantly between the two groups.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003ePPI and mortality during follow-up\u003c/h2\u003e\u003cp\u003eDuring the first-year post TAVR, 32 (12.8%) and 7 (21%) patients underwent PPI (p\u0026thinsp;=\u0026thinsp;0.19) due to relevant indication from the immediate and delayed post-TAVR LBBB groups, respectively. All these PPIs occurred during the first 2 weeks post-TAVR except for 1 PPI from the immediate LBBB group that occurred 41 days post-TAVR. PPI indications during the first 2-weeks post TAVR, included AVB in 24 (77.4%) vs 5 (71.4%), alternating BBB in 3 (9.7%) vs 1 (14.3%) and EPS demonstrating prolonged HV\u0026thinsp;\u0026gt;\u0026thinsp;70 ms in 4 (12.9%) vs 1 (14.3%), p\u0026thinsp;=\u0026thinsp;0.93; in the immediate and delayed LBBB subgroups, respectively. Mortality events during this period of one year, occurred in 50 (20%) and 11 (33.3%), p\u0026thinsp;=\u0026thinsp;0.11, from the immediate and delayed post TAVR LBBB groups, respectively. KM curves of 1- and 5-years follow-up, for PPI, mortality and the combined endpoint of PPI and mortality are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Supplementary Fig.\u0026nbsp;1, respectively. Patients in the delayed LBBB group had a nonsignificant worse outcomes during 1- and 5-years follow-up of both need for PPI and mortality.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003ePredictors for PPI in patients with immediate vs. delayed post TAVR LBBB\u003c/h3\u003e\n\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cb\u003eSupplementary Table\u0026nbsp;1\u003c/b\u003e demonstrate separate comparisons for patients with immediate and delayed post-TAVR LBBB. In each patients\u0026rsquo; group, a comparison is made between those with and without PPI within 2-weeks post-TAVR. In patients with immediate -onset LBBB, baseline, post procedural and maximal QRS width were significantly wider in patients who underwent PPI compared to those who did not. Maximal Δ PR was marginally longer in patients with PPI (p\u0026thinsp;=\u0026thinsp;0.052). In addition, persistence of LBBB was more common among patients who underwent PPI. In contrast, in patients with delayed-onset LBBB, neither QRS width (baseline, post procedural and maximal QRS width), nor LBBB persistence to discharge, were significantly different between patients with and without PPI. Rather, baseline PR was shorter and maximal Δ PR was longer in patients with PPI compared to those without PPI. Of note, among patients with delayed-onset LBBB, PPI was more common among men compared to woman. An example of sequential ECG changes in a patient with post-TAVR delayed-onset LBBB is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eECG parameters of patients with immediate and delayed LBBB with and without early PPI within 2 weeks\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eImmediate LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep Value\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003eDelayed LBBB\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003ep Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;247) *\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;32) *\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo PPI (n\u0026thinsp;=\u0026thinsp;216)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePPI (n\u0026thinsp;=\u0026thinsp;31)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eNo PPI (n\u0026thinsp;=\u0026thinsp;25)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePPI (n\u0026thinsp;=\u0026thinsp;7)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePre TAVR ECG\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSinus Rhythm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e199 (92.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27 (87.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.313\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e21 (84.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5 (71.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS axis (N/L/R)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e150(69.4)/66(30.6)/0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15(48.4)/16(51.6)/0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.02\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e14 (56)/11(44)/0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e3(42.9)/3(42.9)/1(14.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.292\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePR duration\u003csup\u003e**\u003c/sup\u003e (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e189.1\u0026thinsp;\u0026plusmn;\u0026thinsp;38.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e189.6\u0026thinsp;\u0026plusmn;\u0026thinsp;37.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.613\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e180.8\u0026thinsp;\u0026plusmn;\u0026thinsp;26.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e150.8\u0026thinsp;\u0026plusmn;\u0026thinsp;14.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.019\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS duration (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e92.31\u0026thinsp;\u0026plusmn;\u0026thinsp;12.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e97.16\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.048\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e94.32\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e89.43\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.324\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePost TAVR ECG\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSinus rhythm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e197 (91.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e28 (90.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.745\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e21 (84.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5 (71.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.59\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eQRS axis (N/L/R)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51(23.6)/163(75.5)/2(0.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6(19.4)/25(80.6)/0(0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.196\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3(12)/22(88)/0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2(28.6)/5(71.4)/0(0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.296\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAxis change (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e105 (48.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (45.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.719\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e11 (44)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2 (28.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.671\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost TAVR PR duration (ms)\u003csup\u003e**,$\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e201.7\u0026thinsp;\u0026plusmn;\u0026thinsp;37.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e212.2\u0026thinsp;\u0026plusmn;\u0026thinsp;39.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.174\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e197.8\u0026thinsp;\u0026plusmn;\u0026thinsp;43.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e219.2\u0026thinsp;\u0026plusmn;\u0026thinsp;76.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.569\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost TAVR QRS duration (ms)\u003csup\u003e$\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e144.5\u0026thinsp;\u0026plusmn;\u0026thinsp;15.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e150.9\u0026thinsp;\u0026plusmn;\u0026thinsp;15.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e141.3\u0026thinsp;\u0026plusmn;\u0026thinsp;14.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e143.2\u0026thinsp;\u0026plusmn;\u0026thinsp;13.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.688\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal PR duration (ms)\u003csup\u003e**,#\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e226.4\u0026thinsp;\u0026plusmn;\u0026thinsp;43.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e238.4\u0026thinsp;\u0026plusmn;\u0026thinsp;36.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.136\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e235.9\u0026thinsp;\u0026plusmn;\u0026thinsp;46.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e265.0\u0026thinsp;\u0026plusmn;\u0026thinsp;26.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.195\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal QRS duration (ms)\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e148.7\u0026thinsp;\u0026plusmn;\u0026thinsp;15.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e158.2\u0026thinsp;\u0026plusmn;\u0026thinsp;16.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e145.08\u0026thinsp;\u0026plusmn;\u0026thinsp;16.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e151.5\u0026thinsp;\u0026plusmn;\u0026thinsp;17.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.503\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eΔ PR (ms)\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13.1\u0026thinsp;\u0026plusmn;\u0026thinsp;34.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22.5\u0026thinsp;\u0026plusmn;\u0026thinsp;32.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.206\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e16.9\u0026thinsp;\u0026plusmn;\u0026thinsp;38.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e63\u0026thinsp;\u0026plusmn;\u0026thinsp;74.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.496\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal Δ PR (ms) \u003csup\u003e**,\u0026amp;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e37.8\u0026thinsp;\u0026plusmn;\u0026thinsp;34.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e49.7\u0026thinsp;\u0026plusmn;\u0026thinsp;32.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.052\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e55.09\u0026thinsp;\u0026plusmn;\u0026thinsp;43.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e120\u0026thinsp;\u0026plusmn;\u0026thinsp;27.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eΔ QRS (ms)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e52.2\u0026thinsp;\u0026plusmn;\u0026thinsp;16.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e53.7\u0026thinsp;\u0026plusmn;\u0026thinsp;15.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.648\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e47.0\u0026thinsp;\u0026plusmn;\u0026thinsp;13.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e53.8\u0026thinsp;\u0026plusmn;\u0026thinsp;18.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.755\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal Δ QRS (ms)\u003csup\u003e\u0026amp;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56.4\u0026thinsp;\u0026plusmn;\u0026thinsp;16.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e61.09\u0026thinsp;\u0026plusmn;\u0026thinsp;16.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e50.7\u0026thinsp;\u0026plusmn;\u0026thinsp;14.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e62.1\u0026thinsp;\u0026plusmn;\u0026thinsp;16.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.191\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDays to LBBB\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1 (1-2.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2 (1\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.72\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDay of maximal PR duration\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (0\u0026ndash;4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4 (2\u0026ndash;5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e3 (1.5-3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.25\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDay of maximal QRS duration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0\u0026ndash;1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (0\u0026ndash;2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2 (1\u0026ndash;5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.97\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePersistent LBBB upon discharge^\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e112 (51.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30 (96.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17 (68)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e7 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e\u003cp\u003e0.15\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eLBBB\u0026thinsp;=\u0026thinsp;left bundle branch block; N/L/R\u0026thinsp;=\u0026thinsp;normal/left/right; PPI\u0026thinsp;=\u0026thinsp;permanent pacemaker implantation; TAVR\u0026thinsp;=\u0026thinsp;transcatheter aortic valve replacement\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003e*\u003c/sup\u003e 2 patients from the immediate and 1 from the delayed LBBB groups, who died on days 0, 1 and 4 post TAVR were excluded from this analysis.\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e** Data not available for 25 patients with atrial fibrillation (20 with immediate LBBB and 5 with delayed LBBB)\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003e$\u003c/sup\u003e In first ECG documentation of LBBB after TAVR\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003e#\u003c/sup\u003e Longest documented PR/QRS during hospital follow-up\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003e\u0026amp;\u003c/sup\u003e Δ between maximal PR/QRS to pre-TAVR PR/QRS\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e^ Persistent to discharge or to in hospital pacemaker implantation or mortality.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eROC analysis was conducted to define the best cutoff of maximal Δ PR differentiating the need for PPI among patients with delayed and with immediate-onset post TAVR LBBB. An area under the curve of 0.92 (95% CI 0.79\u0026ndash;1.05, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and 0.62 (95% CI 0.52\u0026ndash;0.72, p\u0026thinsp;=\u0026thinsp;0.02), respectively was found (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Among patients with delayed-onset post-TAVR LBBB, a cutoff of maximal Δ PR of 115 ms had a specificity of 91% and a sensitivity of 80% in predicting the need for PPI. While, in patients with immediate post TAVR LBBB, a cutoff of maximal Δ PR of 20.5 ms had a specificity of 34% and a sensitivity of 93% in predicting a need for PPI.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eMain findings\u003c/h2\u003e\u003cp\u003eOur study which was conducted on a cohort of 1469 consecutive TAVR patients exhibited, in accordance with previous reports,\u003csup\u003e1\u0026ndash;3, 14\u003c/sup\u003e that post-TAVR new onset LBBB occurs in ~\u0026thinsp;20% of patients. However, it demonstrated that in 11.7% of patients with new-onset LBBB, appearance of LBBB may be delayed and not manifest immediately post TAVR. The clinical consequences of delayed compared to immediate post-TAVR LBBB were shown for the first time, to be comparable, with similar rates of PPI need and mortality, both early and during long term follow-up. Nevertheless, different ECG abnormalities correlated with a need for PPI, while in patients with immediate post TAVR LBBB, QRS width was the dominant discriminating factor, in patients with delayed post TAVR LBBB, the maximal Δ PR differentiated between patients with and without need for PPI. In the delayed post TAVR LBBB group, a cutoff of Δ PR of 115 ms had a sensitivity and specificity of 80% and 91%, respectively for need of PPI.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003ePrevious studies\u003c/h2\u003e\u003cp\u003eMost studies on post TAVR new onset LBBB focused on either, the best approach to risk stratify these patients,\u003csup\u003e1\u0026ndash;3, 15\u003c/sup\u003e or on LBBB persistence in relation to clinical endpoints, including PPI need, LV function deterioration, and mortality.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e Few of these studies showed that the appearance of post TAVR new onset LBBB may be delayed in 6.5\u0026ndash;15% of patients.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e Massoullie et al studied a cohort of 183 patients with post TAVR new onset LBBB.\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e In ~\u0026thinsp;15% the appearance of LBBB was delayed (median 2 days, range 1\u0026ndash;3 days post TAVR). Urena et al studied, 61 cases of new-onset post-TAVR LBBB, using balloon- expandable valve. Fifty-seven (93.4%) new-onset LBBB cases were seen immediately on the first post-TAVR ECG, however, in 4 (6.5%), the LBBB appearance was not immediate.\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e Of note, in only 1 of these 4 cases, no conduction abnormality was seen on the first post-TAVR ECG. The other 3 had either, new left anterior hemiblock or incomplete LBBB on their first ECG before developing LBBB. Houthuizen et al reported an incidence of 12% (21 cases out of 175 new onset post TAVR LBBB) of subacute LBBB, defined as occurring more than 24 hours post TAVR.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e Finally, Testa et al reported an incidence of 10.1% delayed LBBB (40 out of 394 new onset LBBB cases), based on immediate and predischarge post TAVR ECGs.\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e Of note, rate of LBBB persistence to discharge in patients with delayed onset LBBB, was either not specifically reported,\u003csup\u003e6, 16\u003c/sup\u003e or was lower in 1 study reaching 43% in the delayed LBBB group compared to 65% in the immediate LBBB group.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e In the study by Testa et al, LBBB persistence to discharge was 100% by definition, as only the immediate and predischarge ECGs were analyzed.\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e None of these studies defined the specific characteristics, risk factors for PPI need and prognosis of the delayed post TAVR LBBB patient population.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003ePossible mechanism of delayed onset LBBB and clinical implications\u003c/h2\u003e\u003cp\u003eTAVR related insult to the conduction system may occur as a consequence of direct trauma during different stages of the procedure, causing immediately manifested conduction abnormality.\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e Post procedurally, continued mechanical pressure, valve self-expansion and development of edema inflammation and fibrosis may further compromise the conduction system\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e manifesting as further worsening of an immediately manifested conduction abnormality or development of new delayed conduction abnormality. Interestingly, in the current study, patients with delayed onset LBBB could be stratified into high and low likelihood of PPI need within 2 weeks post TAVR, using maximal Δ PR which was mostly\u0026thinsp;\u0026gt;\u0026thinsp;115 ms in those who underwent PPI. It is possible that insult to different parts along the conduction system accounts for the appearance of delayed LBBB with or without continued conduction worsening and PPI need. In those with delayed LBBB and no significant PR change the insult may be confined to the LBB while in those with significant PR prolongation the insult may involve the His bundle and fibers that are destined to form the LBB or involve both bundles with more pronounced damage to the LBB and thus manifests with both LBBB and PR prolongation with increased risk for developing AV block. The finding that maximal Δ PR was longer in patients with delayed compared to immediate LBBB, regardless of PPI (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), suggests that as a group the average insult to the conduction system was more proximal manifesting with both PR prolongation and LBBB. Clinically, the current study suggests that patients with delayed LBBB and especially those with significant PR interval prolongation should be monitored for longer times, with extended hospitalization and possibly even monitored post discharge. In addition, EPS maybe be used as per treating physician practice.\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e\u003cp\u003eNotably, while we have previously published that PR prolongation per se in patients with narrow QRS, is not predictive of the need for PPI,\u003csup\u003e4\u003c/sup\u003e its combination with LBBB and especially delayed LBBB may warrant further attention and prolonged monitoring.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003eLimitations\u003c/h2\u003e\u003cp\u003eAn inherent study limitation is related to its observational retrospective design. ECGs were performed daily and were meticulously analyzed. However, continuous telemetry data, both during and post TAVR, was not available for analysis and therefore we cannot rule out the occurrence of few transient LBBB or AVB cases that went unnoticed. Despite analyzing a large database of almost 1500 TAVR cases, the ultimate number of patients with delayed LBBB and especially those who needed PPI was relatively small, precluding performance of multivariate analysis, and enabling type II error due to small numbers (notably, there was a nonsignificant trend to worse outcomes in the delayed LBBB group). Further larger studies may clarify this point. Finally, according to the study design the cause of delayed versus immediate post TAVR LBBB was not explored, however, our main goal was to describe the phenomenon of delayed LBBB and possible risk factors for PPI once it occurred.\u003c/p\u003e\u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAround 12% of post-TAVR new onset LBBB cases are delayed and not seen immediately after the procedure. Prognosis of these patients, in terms of PPI need and mortality, is not significantly different from patients with immediate post TAVR-LBBB. However, ECG parameters that correspond to higher PPI risk are different. While QRS duration correlates with PPI need in patients with immediate LBBB, \u0026Delta; PR \u0026gt; 115 ms correlates with PPI need in patients with delayed LBBB.\u0026nbsp;\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAVB = atrio-ventricular block\u003c/p\u003e\n\u003cp\u003eECG = electrocardiogram\u003c/p\u003e\n\u003cp\u003eEPS = electrophysiological study\u003c/p\u003e\n\u003cp\u003eLBBB = left bundle branch block\u003c/p\u003e\n\u003cp\u003ePPI = permanent pacemaker implantation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRBBB = right bundle branch block\u003c/p\u003e\n\u003cp\u003eROC = receiver operator characteristics\u003c/p\u003e\n\u003cp\u003eSAVR = surgical\u0026nbsp;aortic valve replacement\u003c/p\u003e\n\u003cp\u003eSSS = sick sinus syndrome\u003c/p\u003e\n\u003cp\u003eTAVR = transcatheter aortic valve replacement\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eDisclosures:\u003c/h2\u003e\n\u003cp\u003e\u003cstrong\u003eYM\u003c/strong\u003e: Consultant for Edwards Lifesciences (Irvine, California); \u003cstrong\u003eDD\u003c/strong\u003e: Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); \u003cstrong\u003eMG\u003c/strong\u003e advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYM: Consultant for Edwards Lifesciences (Irvine, California); DD: Consultant and proctor for Medtronic cardiovascular (Minneapolis, Minnesota) and Edwards Lifesciences (Irvine, California); MG advisory board Medtronic cardiovascular (Minneapolis, Minnesota). All other authors declare having no potential conflict of interest.\u003c/p\u003e\n\u003ch2\u003eFunding:\u003c/h2\u003e\n\u003cp\u003eEisenberg R\u0026amp;D authority, Shaare Zedek Medical Center.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eMS, OTB and YM wrote the main manuscript and prepared the figures and Tables. MZ and NP helped with data acquisition. All authors reviewed the manuscript.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe data underlying this article will be shared on reasonable request to the corresponding author.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAuffret V, Puri R, Urena M, et al. Conduction Disturbances After Transcatheter Aortic Valve Replacement: Current Status and Future Perspectives. Circulation Sep. 2017;12:136:1049\u0026ndash;69.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRodes-Cabau J, Ellenbogen KA, Krahn AD, et al. Management of Conduction Disturbances Associated With Transcatheter Aortic Valve Replacement: JACC Scientific Expert Panel. J Am Coll Cardiol Aug. 2019;27:74:1086\u0026ndash;106.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGlikson M, Nielsen JC, Kronborg MB, et al. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. Europace Jan. 2022;4:24:71\u0026ndash;164.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePerel N, Tovia-Brodie O, Schnur A, et al. Post-transcatheter aortic valve implantation isolated PR prolongation: incidence and clinical significance. Europace Dec. 2023;28:26.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMichowitz Y, Yagel O, Shrem M et al. New-Onset RBBB After Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation. JACC Clin Electrophysiol Jul 29 2025.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUrena M, Mok M, Serra V, et al. Predictive factors and long-term clinical consequences of persistent left bundle branch block following transcatheter aortic valve implantation with a balloon-expandable valve. J Am Coll Cardiol Oct. 2012;30:60:1743\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eUrena M, Webb JG, Cheema A, et al. Impact of new-onset persistent left bundle branch block on late clinical outcomes in patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve. JACC Cardiovasc Interv Feb. 2014;7:128\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNuis RJ, Van Mieghem NM, Schultz CJ, et al. Timing and potential mechanisms of new conduction abnormalities during the implantation of the Medtronic CoreValve System in patients with aortic stenosis. Eur Heart J Aug. 2011;32:2067\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eReiter C, Lambert T, Kellermair J, et al. Intraprocedural dynamics of cardiac conduction during transcatheter aortic valve implantation: Assessment by simultaneous electrophysiological testing. Heart Rhythm Mar. 2021;18:419\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHouthuizen P, van der Boon RM, Urena M, et al. Occurrence, fate and consequences of ventricular conduction abnormalities after transcatheter aortic valve implantation. EuroIntervention Feb. 2014;9:1142\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003evan Gils L, Baart S, Kroon H, et al. Conduction dynamics after transcatheter aortic valve implantation and implications for permanent pacemaker implantation and early discharge: the CONDUCT-study. Europace Dec. 2018;1:20:1981\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChua AP, Myagmardorj R, Nabeta T, et al. Conduction Disorders After Transcatheter Aortic Valve Implantation: Evolution Over Time and Association With Long-Term Outcomes. Struct Heart May. 2025;9:100428.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSurawicz B, Childers R, Deal BJ, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol Mar. 2009;17:53:976\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFaroux L, Chen S, Muntane-Carol G, et al. Clinical impact of conduction disturbances in transcatheter aortic valve replacement recipients: a systematic review and meta-analysis. Eur Heart J Aug. 2020;1:41:2771\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTovia-Brodie O, Ben-Haim Y, Joffe E, et al. The value of electrophysiologic study in decision-making regarding the need for pacemaker implantation after TAVI. J Interv Card Electrophysiol Mar. 2017;48:121\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMassoullie G, Ploux S, Souteyrand G, et al. Incidence and management of atrioventricular conduction disorders in new-onset left bundle branch block after TAVI: A prospective multicenter study. Heart Rhythm May. 2023;20:699\u0026ndash;706.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTesta L, Latib A, De Marco F, et al. Clinical impact of persistent left bundle-branch block after transcatheter aortic valve implantation with CoreValve Revalving System. Circulation Mar. 2013;26:127:1300\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Left Bunder Branch Block, transcatheter aortic valve replacement (TAVR), permanent pacemaker implantation (PPI), delayed, immediate","lastPublishedDoi":"10.21203/rs.3.rs-8121179/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8121179/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Characteristics of patients with delayed compared to immediate new onset left bundle branch block (LBBB) after trans catheter aortic valve replacement (TAVR) are poorly defined.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjectives\u003c/strong\u003e: To describe the incidence and features of patients with delayed post TAVR LBBB as well as risk factors for permanent pacemaker implantation (PPI).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: \u0026nbsp;1469 consecutive TAVR patients were screened for the occurrence of new onset LBBB. ECG was performed within 1 week before the procedure, immediately post procedure, and daily thereafter until discharge. According to the immediate post TAVR ECG, patients were divided into 2 groups, immediate and delayed new onset LBBB. \u0026nbsp;Both groups were followed for the occurrence of PPI and mortality\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: \u0026nbsp;Among patients who underwent TAVR, 296 (20.1%) developed new-onset LBBB, of whom, 282 were included the present study. LBBB occurred immediately after the procedure in 249 patients (88.3%) and was delayed in 33 patients (11.7%). Rates of both early PPI within 2 weeks as well as long term PPI and mortality were comparable between patients with immediate vs. delayed onset LBBB. In patients with immediate LBBB, QRS width correlated with a need for PPI, while in patients with delayed LBBB, PR prolongation of ≥ 115 ms differentiated between patients with and without PPI.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e: The appearance of new onset post TAVR LBBB may be delayed in ~12% of patients. These patients exhibit similar rates of PPI need and mortality; however different ECG parameters signify high risk for PPI need among these patients.\u003c/p\u003e","manuscriptTitle":"Immediate vs Delayed Left Bundle Branch Block after Transcatheter Aortic Valve Replacement: Incidence and Risk Factors for Permanent Pacemaker Implantation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-01 08:39:14","doi":"10.21203/rs.3.rs-8121179/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"79b39618-b732-41f1-bcc2-8176bd6e0ab2","owner":[],"postedDate":"December 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-02-23T16:07:49+00:00","versionOfRecord":{"articleIdentity":"rs-8121179","link":"https://doi.org/10.1007/s10840-026-02248-3","journal":{"identity":"journal-of-interventional-cardiac-electrophysiology","isVorOnly":false,"title":"Journal of Interventional Cardiac Electrophysiology"},"publishedOn":"2026-02-19 15:59:37","publishedOnDateReadable":"February 19th, 2026"},"versionCreatedAt":"2025-12-01 08:39:14","video":"","vorDoi":"10.1007/s10840-026-02248-3","vorDoiUrl":"https://doi.org/10.1007/s10840-026-02248-3","workflowStages":[]},"version":"v1","identity":"rs-8121179","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8121179","identity":"rs-8121179","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}