The Relationship Between Premature Ventricular Complexes Burden and Cardiac-Electrophysiologic Balance Index After Premature Ventricular Complex Catheter Ablation

The Relationship Between Premature Ventricular Complexes Burden and Cardiac-Electrophysiologic Balance Index After Premature Ventricular Complex Catheter Ablation | 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 The Relationship Between Premature Ventricular Complexes Burden and Cardiac-Electrophysiologic Balance Index After Premature Ventricular Complex Catheter Ablation Can Özkan, Berat Uğuz, İsmet Zengin, Ahmet Yıldırım This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4559507/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Backround Sudden cardiac death due to ventricular tachyarrhythmias is a global concern. Electrocardiogram (ECG) parameters can predict ventricular arrhythmias. Premature ventricular complexes (PVCs) are common arrhythmias, potentially triggering life-threatening events. The index of cardiac electrophysiological balance (iCEB) is hypothesized to predict arrhythmias. This study aimed to correlate iCEB with PVC burden post-catheter ablation. Methods Ninety-eight patients without structural heart disease underwent PVC catheter ablation. Successful ablation was defined as PVC elimination without recurrence. iCEB was calculated from resting ECG. Patients were categorized based on PVC burden. Statistical analysis was performed using SPSS. Results No significant differences in cardiovascular risk factors were found among groups. Lower iCEBc was associated with higher PVC burden. An iCEBc value of 4.87 had 72% specificity and 65.2% sensitivity for predicting PVC burden. Conclusion The study suggests that iCEBc is a promising predictor for post-ablation PVC burden, indicating its potential clinical utility. Further research validating these findings and elucidating underlying mechanisms is needed to enhance risk stratification and optimize patient management. Integrating iCEBc assessment into routine practice may aid in identifying high-risk patients and implementing targeted interventions. iCEBc is a non-invasive marker for predicting PVC burden following PVC catheter ablation in patients with structurally normal hearts. Cardiac-Electrophysiologic Balance Index Catheter Ablation Premature Ventricular Complexes Figures Figure 1 Figure 2 INTRODUCTION Sudden cardiac death due to sudden ventricular tachyarrhythmias remains a significant problem globally. As a non-invasive and easily accessible test, the electrocardiogram (ECG) can reflect the electrical activity of the heart well. Some ECG parameters, such as conduction and repolarization markers, have been used to quantify patients’ risk of ventricular tachycardia (VT) or ventricular fibrillation (VF) and predict the risk of sudden cardiac deat ( 1 ). One of the most common arrhythmias encountered in clinical practice is premature ventricular complexes (PVCs) ( 2 ), which are one of the most common causes of palpitations. They can also present with symptoms such as presyncope, dyspnea, and fatigue and are often detected incidentally on an ECG ( 3 , 4 ). A PVC burden of more than 10% on 24-hour ambulatory rhythm monitoring increases the risk of heart failure ( 5 ). Ablation of frequent PVCs improves left ventricular ejection fraction (LVEF) in patients with left ventricular (LV) systolic dysfunction ( 6 ). Some studies have shown that catheter ablation is superior to pharmacologic therapy for reducing PVC burden and improving cardiac function ( 7 ). The index of cardiac electrophysiological balance (iCEB), an index for predicting ventricular arrhythmia, is calculated as the QT interval divided by QRS duration (QT/QRS) ( 8 ). It was hypothesized that iCEB is equivalent to the cardiac wavelength λ and that an increased or decreased value of iCEB could potentially predict an increased susceptibility to Torsades de Pointes (TdP) or non-TdP-mediated VT/VF, respectively ( 9 ) (Fig. 1 ). In general, PVCs are benign in patients without structural heart disease; however, PVCs can be a trigger for life-threatening arrhythmias such as VT and VF ( 10 ). Figure 1 . A schematic overview of iCEB. Imbalance between depolarization (QRS duration) and repolarization (QT interval) of cardiac electrophysiology and arrhythmias. This study aimed to determine the relationship between the iCEB in patients with a structurally normal heart and PVC load following catheter ablation in patients undergoing PVC catheter ablation. MATERIALS AND METHOD In this retrospective study, 98 patients without structural heart disease presented to a cardiology outpatient clinic and underwent 24-hour ECG Holter monitoring. Patients who were eligible for PVC catheter ablation and gave consent were included. After 1 month, patients with PVCs with the same morphology as the initial PVC morphology on ECG Holter were included in the study. Patients with any known genetic or structural heart disease were excluded. Patients with a history of coronary intervention and/or coronary surgery, history of valvular surgery, ejection fraction ≤ 50%, atrial fibrillation, intracardiac implantable devices, thyroid abnormalities, liver or kidney diseases, active infection, presence of malignancy, and patients taking anti-arrhythmic drugs were also excluded. Patients with more than one PVC morphology were excluded. Patients with symptomatic or frequent PVCs who underwent acute successful ablation with a follow-up of at least 1 month were included. Acute successful ablation was defined as the elimination of PVCs without intraoperative recurrence during or outside isoproterenol testing. Mapping and Ablation A standard electrophysiology study was performed on all patients. Three-dimensional electroanatomic mapping was used in all cases. PVC mapping and the ablation technique and equipment were left to the discretion of the electrophysiologist involved. In general, clinical PVC patterns were captured for velocity map imaging before sedation. If no PVCs were initially seen, isoproterenol and/or phenylephrine were given to induce PVCs. A combination of pace mapping and activation mapping was applied whenever possible to localize PVC sources. After successful ablation of the PVC site, a 30-minute waiting period was observed, during which high doses of isoproterenol (up to 30 µg/min) were administered. Ablation success was defined as the absence of intraprocedural PVC recurrence ( 11 ). Follow-up Following ablation, PVC loads were monitored with a 24-hour rhythm Holter. One month after the initial procedure, all patients underwent 24-hour ECG Holter monitoring. A cardiologist analyzed the PVCs and corrected the results in the automated computer system. The automated system determined the total number of PVCs. Patients were divided into the following four groups according to their PVC burden: One month after the initial procedure, post catheter ablation PVC burden up to 5% was defined as Group 1, PVCs between 6% and 10% as Group 2, PVCs between 11% and 20% as Group 3 and PVCs more than 20% as Group 4. Comparison of Index and Recurrent PVC Source Locations For statistical analysis, PVC locations were grouped into the following categories: ( 1 ) right ventricular outflow tract (RVOT), ( 2 ) left ventricular outflow tract (LVOT), and coronary cusps. The iCEB was determined by pre-procedure resting ECG of patients without PVCs. All measurements were performed using MUSE software (GE Healthcare). The 12-lead ECGs were recorded at a gain of 10 mm/mV and a paper speed of 25 mm/s at rest in the supine position; QRS duration, QT interval, and heart rate were determined. Measurements were made at lead II and lead V5, and the longest QT interval was selected for analysis. The QT interval was corrected using Bazett’s formula (QTc = QT/(RR1/2)). The iCEB and corrected iCEB (iCEBc) were calculated; the iCEB by dividing QT by QRS duration, and iCEBc by dividing QTc by QRS duration. iCEB was calculated from pre-procedural ECGs of patients without PVCs. Statistical Analysis Here, SPSS 28.0 Statistical Package for Windows (SPSS Inc., Chicago, IL, USA) was used. The Kolmogorov–Smirnov test was used to determine the distribution pattern of the parameters. Continuous parameters with normal distribution are presented as mean ± standard deviation, parameters with non-normal distribution are presented as median, and categorical variables are presented as numbers and percentages. Analysis of variance tests or Kruskal–Wallis tests were used to compare continuous variables according to iCEB groups. The chi-squared (χ 2 ) test was used to compare categorical variables. Multivariate logistic regression analysis was used to identify independent parameters associated with > 20% PVCs. RESULTS Table 1 shows the demographic, clinical, and laboratory characteristics of the study population. There were no significant differences between the groups in terms of cardiovascular risk factors, including age, gender, coronary artery disease, diabetes, or hypertension. Statin and diuretic use and platelet levels were significantly lower in the highest PVC group than in the other groups; EF was similar between groups. Table 1 Demographic, clinical, and laboratory characteristics of the study population. ACEI: angiotensin converting enzyme inhibitor; ALT: alanine transaminase; ARB: angiotensin receptor blocker; AST: aspartate transferase; EF: ejection fraction; GFR: glomerular filtration rate; LV: left ventricle; WBC: white blood cell. Bold values indicate statistical significance at the p 6% and ≤ 10% PVCs) (n = 8) Group 3 (> 11% and ≤ 20% PVCs) (n = 6) Group 4 (> 20% PVCs) (n = 9) p Age (years) 53.5 ± 14.9 52.7 ± 11.0 55.8 ± 13.2 55.3 ± 15.7 0.964 Male, n (%) 34 (45.3) 3 (37.5) 4 (66.7) 6 (66.7) 0.483 Hypertension, n (%) 41 (54.7) 4 (50) 4 (66.7) 5 (55.6) 0.955 Diabetes mellitus, n (%) 20 (26.7) 2 (25) 3 (50) 4 (44.4) 0.434 Coronary artery disease, n (%) 28 (37.3) 3 (37.5) 4 (66.7) 7 (77.8) 0.077 Medication, n (%) ACEI/ARB, n(%) 38 (50.7) 6 (75) 4 (66.7) 7 (77.8) 0.292 Beta blocker, n (%) 62 (82.7) 5 (62.5) 5 (83.3) 8 (88.9) 0.617 Statin, n (%) 18 (24) 3 (37.5) 4 (66.7) 6 (66.7) 0.010 Diuretic, n (%) 6 ( 8 ) 3 (37.5) 3 (50) 2 (22.2) 0.021 Hemoglobin (g/L) 13.4(9.6;17.4) 13.1 (10.0;15.4) 13.2 (12.8;16.4) 13.5 (11.2;16.0) 0.729 WBC (10 3 /µL) 8.1 ± 0.2 7.8 ± 0.5 9.1 ± 1.0 7.9 ± 0.4 0.609 Platelets (10 3 /µL) 254 ± 62.3 264 ± 90.3 213 ± 65.7 200 ± 26.9 0.046 Creatinine (mg/dL) 0.79(0.48;1.9) 0.78(0.50;1.0) 0.83(0.65;1.45) 0.93(0.74;1.21) 0.262 GFR (mL/min) 90.8 ± 21.1 92.5 ± 17.6 85.6 ± 27.2 86.3 ± 24.8 0.872 Sodium (mmol/L) 140 ± 2.4 140.5 ± 1.6 139 ± 1.7 138 ± 2.6 0.123 Potassium (mmol/L) 4.4 ± 0.4 4.2 ± 0.4 4.6 ± 0.2 4.2 ± 0.3 0.175 Calcium (mg/dL) 9.2 ± 0.4 9.4 ± 0.4 9.5 ± 0.2 9.2 ± 0.4 0.626 AST (U/L) 19(10;76) 16(12;31) 16.5(15;21) 20(9;97) 0.389 ALT (U/L) 17(5;159) 16(9;33) 16(10;37) 15(9;34) 0.933 LV EF(%) 60 (55;68) 62(60;65) 60(58;65) 60(55;68) 0.149 ACEI: angiotensin converting enzyme inhibitor; ALT: alanine transaminase; ARB: angiotensin receptor blocker; AST: aspartate transferase; EF: ejection fraction; GFR: glomerular filtration rate; LV: left ventricle; WBC: white blood cell. Bold values indicate statistical significance at the p < 0.05 level. The patients’ ECG parameters are presented in Table 2 . QRS duration was significantly different between groups, with Group 4 having the highest duration (p = 0.004). There was no difference in QT duration; however, iCEB and iCEBc were significantly lower in the highest PVC group (p < 0.001) (Table 2 ). Table 2 Electrocardiographic parameters of the groups. iCEB: index of cardio-electrophysiological balance; iCEBc: corrected index of cardio-electrophysiological balance; ms: millisecond; PVCs: premature ventricular complexes; QTc: corrected QT interval. Bold values indicate statistical significance at the p 6% and ≤ 10% PVCs) (n = 8) Group 3 (> 11% and ≤ 20% PVCs) (n = 6) Group 4 (> 20% PVCs) (n = 9) p QRS interval (ms) 84(66–144) 90(70–110) 85(74–98) 110(78–162) 0.004 QT interval (ms) 391 ± 29.0 382 ± 30.1 405 ± 27.3 404 ± 32.0 0.294 QTc interval (ms) 438(377–495) 430.5(400–445) 450(375–458) 437(395–525) 0.550 iCEB (QT/QRS ratio) 4.6 ± 0.61 4.3 ± 0.47 4.7 ± 0.68 3.6 ± 0.68 < 0.001 iCEBc (QTc/QRS ratio) 5.2 ± 0.78 4.9 ± 0.70 5.1 ± 0.77 4 ± 0.65 < 0.001 When we performed multiple backward logistic regression analyses with a model including age, platelets and iCEBc, a lower iCEBc (p = 0.003) was associated with higher PVCs (Table 3 ). CI : confidence interval, iCEBc: corrected index of cardio-electrophysiological balance, OR: odds ratio Table 3 Logistic regression analysis of potential predictor factors for premature ventricular complexes burden Univariate analysis Multivariate analysis Variables OR 95%CI p value OR 95%CI p value Age 0.986 0.946–1.028 0.508 Coronary artery disease 1.161 0.214–6.293 0.862 Statin use iCEBc 5.942 0.353 1.180-29.918 0.176–0.707 0.031 0.003 0.384 0.204–0.723 0.003 Receiver operating characteristic analysis revealed that an iCEBc value of 4.87 had 72% specificity and 65.2% sensitivity for predicting PVC burden following PVC catheter ablation (Fig. 2 ). DISCUSSION We aimed to determine the relationship between the iCEBc in patients with structurally normal hearts and post-catheter ablation PVC burden in patients undergoing PVC catheter ablation. Here, iCEBc was significantly associated with post-ablation PVC burden independently, with significantly lower iCEBc values. To the best of our knowledge, this is the first study to investigate the relationship between iCEBc and PVC burden following PVC catheter ablation. Although PVCs are common and generally thought to be harmless, many studies show a higher risk for all-cause and cardiovascular mortality in patients without structural heart disease ( 10 , 12 ). It is now known that PVCs are potentially dangerous to susceptible patients and can occur as triggers of VF and sudden cardiac death. Alternatively, frequent ventricular extrasystoles can also cause cardiomyopathy ( 13 ). However, the mechanism by which PVCs trigger VF in a structurally normal heart remains unclear ( 10 ). The iCEB, the ratio of QT to QRS (QT/QRS) calculated from surface ECG, is a simple ECG marker that can predict ventricular arrhythmogenesis. The iCEB is equivalent to the cardiac wavelength λ, which is measured via invasive electrophysiological study and plays an important role in ventricular arrhythmias. Previous studies have suggested that the iCEB may offer a non-invasive and easily measurable marker to detect increased arrhythmic risk in patients ( 14 ). Increased or decreased values of iCEB are associated with ventricular arrhythmic events ( 15 ). Furthermore, iCEB is associated with long QT and TdP, but also with QT shortening and associated non-TdP-like VT/VF ( 16 ). Due to its non-invasive nature and ease of measurement, it has attracted great interest in clinical practice. Recently, iCEB has been found to be a better predictor of arrhythmia risk compared to the Tp-e interval, QTc interval, and Tp-e/QTc ratio ( 16 ). In a study by Adali et al., iCEBc was found to be a marker that can predict PVCs in patients without structural heart disease ( 5 ). Our study found that iCEBc can predict PVC burden following PVC catheter ablation. QT and QTc intervals include periods of ventricular depolarization and repolarization, and their prolongation poses a risk for malignant ventricular arrhythmias ( 17 ). Our study found no significant difference in QT and QTc intervals. There is very little information about QRS complex dispersion. One study found that QRS duration and dispersion were significantly higher in AMI-related precursors. QRS dispersion was the ECG variable more closely associated with the occurrence of VT and VF, and it also suggested that the likelihood of ventricular arrhythmias is much higher when QRS duration and dispersion are high rather than when QTc duration and dispersion are high ( 18 ). In our study, prolonged QRS duration was found to be statistically significantly higher with PVC burden following PVC catheter ablation. It has been suggested that increased iCEB may trigger a TdP-mediated arrhythmogenic effect, whereas decreased iCEB may cause non-TdP arrhythmias. Furthermore, sotalol use and congenital long QT syndrome, TdP-related arrhythmias, increased both iCEB and iCEBc. In contrast, Brugada syndrome and flecainide use, non-TdP ventricular arrhythmias, decreased iCEB and iCEBc ( 19 ). In our study, iCEB and iCEBc values were significantly lower in the group with a higher PVC burden. LIMITATIONS Our study has a few limitations. First, this is a single-center study involving a smaller number of patients. Second, the patients were not followed up, and the PVC burden was only determined once. Thirdly, a prospective study is essential for clinical events, such as malignant ventricular arrhythmias and sudden cardiac death. Fourtly only two PVC localizations were included in the study. The results may change with the inclusion of other localizations. Finally, the validity of the iCEB values must be correlated with the cardiac wavelength λ measurement determined by the electrophysiological study. CONCLUSION The iCEBc is a novel, non-invasive marker that can predict PVC burden following PVC catheter ablation in patients with structurally normal hearts. Beyond other ECG parameters, the iCEBc can be used as an accurate marker of electrophysiologic balance and arrhythmia risk. Declarations Acknowledgements Not applicable. Author contributions CO conceived and designed the research. IZ, AY analyzed the data and drafted the manuscript. BU, IZ, AY collected the data and performed the research. CO,BU reviewed and edited the manuscript and approved the final version of the manuscript. Funding None. Data availability The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate The study protocol was approved by local ethics committee and was conducted according to the principles of the Declaration of Helsinki. Written informed consent could not be obtained from the patients due to the retrospective design of the study (Institutional Ethics Committee (decision no: 2024-2 / 2, date: 21.02.2024). Consent for publication Not applicable. Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Competing interests The authors declare no competing interests. References Zhang Y-T, Li H-Y, Sun X-T, Tong X-W, Shan Y-Y, Xu Y-X, et al. Relationship between index of cardiac electrophysiological balance, frontal qrs-t angle and retinopathy in people with type 2 diabetes. Metabolic Syndrome and Obesity: Diabetes; 2023. pp. 861–71. Proclemer A, Dagres N, Marinskis G, Pison L, Lip GY, Blomstrom-Lundqvist C, et al. Current practice in Europe: how do we manage patients with ventricular tachycardia? European Heart Rhythm Association survey. Europace. 2013;15(2):167–9. Cantillon DJ. of premature ventricular complexes. Cleve Clin J Med. 2013;80(6):377. Marcus GM. Evaluation and management of premature ventricular complexes. Circulation. 2020;141(17):1404–18. Adali MK, Davutoglu Y, Yilmaz S. The relationship between premature ventricular complexes and index of cardiac-electrophysiological balance. Revista da Associação Médica Brasileira. 2023;69:142–6. Berruezo A, Penela D, Jáuregui B, Soto-Iglesias D, Aguinaga L, Ordóñez A, et al. Mortality and morbidity reduction after frequent premature ventricular complexes ablation in patients with left ventricular systolic dysfunction. EP Europace. 2019;21(7):1079–87. Latchamsetty R, Yokokawa M, Morady F, Kim HM, Mathew S, Tilz R, et al. Multicenter outcomes for catheter ablation of idiopathic premature ventricular complexes. JACC: Clin Electrophysiol. 2015;1(3):116–23. Yücetas SC, Kaya H, Kafadar S, Kafadar H, Tibilli H, Akcay A. Evaluation of index of cardiac-electrophysiological balance in patients with subarachnoid hemorrhage. BMC Cardiovasc Disord. 2022;22(1):1–6. Robyns T, Lu HR, Gallacher DJ, Garweg C, Ector J, Willems R, et al. Evaluation of index of cardio-electrophysiological balance (iCEB) as a new biomarker for the identification of patients at increased arrhythmic risk. Ann Noninvasive Electrocardiol. 2016;21(3):294–304. Luebbert J, Auberson D, Marchlinski F. Premature ventricular complexes in apparently normal hearts. Cardiac Electrophysiol Clin. 2016;8(3):503–14. Oomen A, Dekker L, Meijer A. Catheter ablation of symptomatic idiopathic ventricular arrhythmias: A five-year single-centre experience. Neth Heart J. 2018;26:210–6. Bikkina M, Larson MG, Levy D. Prognostic implications of asymptomatic ventricular arrhythmias: the Framingham Heart Study. Ann Intern Med. 1992;117(12):990–6. Ip JE, Lerman BB. Idiopathic malignant premature ventricular contractions. Trends Cardiovasc Med. 2018;28(4):295–302. Afsin A, Asoglu R, Kobat MA, Asoglu E, Suner A. Evaluation of index of cardio-electrophysiological balance in patients with atrial fibrillation on antiarrhythmic-drug therapy. Cardiol Res. 2021;12(1):37. Özdemir L, Sökmen E. Effect of habitual cigarette smoking on the index of cardiac electrophysiological balance in apparently healthy individuals. J Electrocardiol. 2020;59:41–4. Lu HR, Yan G-X, Gallacher DJ. A new biomarker–index of Cardiac Electrophysiological Balance (iCEB)–plays an important role in drug-induced cardiac arrhythmias: beyond QT-prolongation and Torsades de Pointes (TdPs). J Pharmacol Toxicol Methods. 2013;68(2):250–9. Lim TR, Rangaswami AA, Dubin AM, Kapphahn KI, Sakarovitch C, Long J, et al. QTc prolongation and risk of torsades de pointes in hospitalized pediatric oncology patients. J Pediatr. 2020;217:33–8. Chávez-González E, Jiménez AR, Moreno-Martínez F. QRS duration and dispersion for predicting ventricular arrhythmias in early stage of acute myocardial infraction. Med Intensiva (English Edition). 2017;41(6):347–55. Askin L, Tanrıverdi O. Evaluation of index of cardio-electrophysiological balance in patients with coronary slow flow. Acta Cardiol. 2022;77(4):337–41. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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-4559507","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":320092528,"identity":"5aa99e0a-3522-4a96-8938-408754e78fdf","order_by":0,"name":"Can Özkan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2UlEQVRIiWNgGAWjYPCCBAYG9h4wi4ePeC08ZxgYDgApNuK1SOSAtTAQ1MLffvbgwx9/0uTNJd8efPwxx06GjYH54aMbeLRInMlLNpDgyTHcORvIOLgtGegwNmPjHDxaDBhyzCQMJCoYN9wGMg5uYwZq4WGTxquF/42ZRIJBhf2Gm2dAWuqJ0CIBNPxAQk7ihhs8IC2HCWuRuPHG2LDhQFryhjM5xgZntx3nYWMm4Bf+/hxDYIgl2244fsbwQeW2ant+9uaHj/FpwQKYSVM+CkbBKBgFowALAACxm0WOSLU0/gAAAABJRU5ErkJggg==","orcid":"","institution":"Bursa City Hospital","correspondingAuthor":true,"prefix":"","firstName":"Can","middleName":"","lastName":"Özkan","suffix":""},{"id":320092529,"identity":"9b8b9c77-a079-4aa3-a2c9-3bed7589bde8","order_by":1,"name":"Berat Uğuz","email":"","orcid":"","institution":"Bursa City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Berat","middleName":"","lastName":"Uğuz","suffix":""},{"id":320092530,"identity":"4bed2b18-c954-4618-b8f1-331d913e2755","order_by":2,"name":"İsmet Zengin","email":"","orcid":"","institution":"Bursa City Hospital","correspondingAuthor":false,"prefix":"","firstName":"İsmet","middleName":"","lastName":"Zengin","suffix":""},{"id":320092531,"identity":"9cccbdbd-fabc-46ce-98e6-1998066ee7d9","order_by":3,"name":"Ahmet Yıldırım","email":"","orcid":"","institution":"Bursa City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ahmet","middleName":"","lastName":"Yıldırım","suffix":""}],"badges":[],"createdAt":"2024-06-10 17:32:27","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4559507/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4559507/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":60621345,"identity":"e2b7aa0b-c972-40b3-adda-4fb80924ce4b","added_by":"auto","created_at":"2024-07-18 21:01:02","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":25988,"visible":true,"origin":"","legend":"\u003cp\u003eA schematic overview of iCEB. Imbalance between depolarization (QRS duration) and repolarization (QT interval) of cardiac electrophysiology and arrhythmias.\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4559507/v1/56b424a68f21611ae6940e68.jpg"},{"id":60620599,"identity":"ce4f47e6-af88-47f5-b401-d29f174c4cd8","added_by":"auto","created_at":"2024-07-18 20:53:02","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":29856,"visible":true,"origin":"","legend":"\u003cp\u003eROC curve analysis\u003c/p\u003e","description":"","filename":"Picture2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4559507/v1/b24553b40fd12ddaab76d4cc.jpg"},{"id":71727904,"identity":"59cd247c-838a-46db-a468-14f79c45eb2d","added_by":"auto","created_at":"2024-12-18 06:24:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":660414,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4559507/v1/8e462d5d-574f-4d4a-8b1c-2f3439ba8eda.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Relationship Between Premature Ventricular Complexes Burden and Cardiac-Electrophysiologic Balance Index After Premature Ventricular Complex Catheter Ablation","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eSudden cardiac death due to sudden ventricular tachyarrhythmias remains a significant problem globally. As a non-invasive and easily accessible test, the electrocardiogram (ECG) can reflect the electrical activity of the heart well. Some ECG parameters, such as conduction and repolarization markers, have been used to quantify patients\u0026rsquo; risk of ventricular tachycardia (VT) or ventricular fibrillation (VF) and predict the risk of sudden cardiac deat (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOne of the most common arrhythmias encountered in clinical practice is premature ventricular complexes (PVCs) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e), which are one of the most common causes of palpitations. They can also present with symptoms such as presyncope, dyspnea, and fatigue and are often detected incidentally on an ECG (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). A PVC burden of more than 10% on 24-hour ambulatory rhythm monitoring increases the risk of heart failure (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Ablation of frequent PVCs improves left ventricular ejection fraction (LVEF) in patients with left ventricular (LV) systolic dysfunction (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Some studies have shown that catheter ablation is superior to pharmacologic therapy for reducing PVC burden and improving cardiac function (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe index of cardiac electrophysiological balance (iCEB), an index for predicting ventricular arrhythmia, is calculated as the QT interval divided by QRS duration (QT/QRS) (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). It was hypothesized that iCEB is equivalent to the cardiac wavelength λ and that an increased or decreased value of iCEB could potentially predict an increased susceptibility to Torsades de Pointes (TdP) or non-TdP-mediated VT/VF, respectively (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In general, PVCs are benign in patients without structural heart disease; however, PVCs can be a trigger for life-threatening arrhythmias such as VT and VF (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. \u003cb\u003eA schematic overview of iCEB. Imbalance between depolarization (QRS duration) and repolarization (QT interval) of cardiac electrophysiology and arrhythmias.\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThis study aimed to determine the relationship between the iCEB in patients with a structurally normal heart and PVC load following catheter ablation in patients undergoing PVC catheter ablation.\u003c/p\u003e"},{"header":"MATERIALS AND METHOD","content":"\u003cp\u003eIn this retrospective study, 98 patients without structural heart disease presented to a cardiology outpatient clinic and underwent 24-hour ECG Holter monitoring. Patients who were eligible for PVC catheter ablation and gave consent were included. After 1 month, patients with PVCs with the same morphology as the initial PVC morphology on ECG Holter were included in the study. Patients with any known genetic or structural heart disease were excluded. Patients with a history of coronary intervention and/or coronary surgery, history of valvular surgery, ejection fraction\u0026thinsp;\u0026le;\u0026thinsp;50%, atrial fibrillation, intracardiac implantable devices, thyroid abnormalities, liver or kidney diseases, active infection, presence of malignancy, and patients taking anti-arrhythmic drugs were also excluded. Patients with more than one PVC morphology were excluded.\u003c/p\u003e \u003cp\u003ePatients with symptomatic or frequent PVCs who underwent acute successful ablation with a follow-up of at least 1 month were included. Acute successful ablation was defined as the elimination of PVCs without intraoperative recurrence during or outside isoproterenol testing.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eMapping and Ablation\u003c/h2\u003e \u003cp\u003eA standard electrophysiology study was performed on all patients. Three-dimensional electroanatomic mapping was used in all cases. PVC mapping and the ablation technique and equipment were left to the discretion of the electrophysiologist involved. In general, clinical PVC patterns were captured for velocity map imaging before sedation. If no PVCs were initially seen, isoproterenol and/or phenylephrine were given to induce PVCs. A combination of pace mapping and activation mapping was applied whenever possible to localize PVC sources. After successful ablation of the PVC site, a 30-minute waiting period was observed, during which high doses of isoproterenol (up to 30 \u0026micro;g/min) were administered. Ablation success was defined as the absence of intraprocedural PVC recurrence (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eFollow-up\u003c/h2\u003e \u003cp\u003eFollowing ablation, PVC loads were monitored with a 24-hour rhythm Holter. One month after the initial procedure, all patients underwent 24-hour ECG Holter monitoring. A cardiologist analyzed the PVCs and corrected the results in the automated computer system. The automated system determined the total number of PVCs. Patients were divided into the following four groups according to their PVC burden:\u003c/p\u003e \u003cp\u003eOne month after the initial procedure, post catheter ablation PVC burden up to 5% was defined as Group 1, PVCs between 6% and 10% as Group 2, PVCs between 11% and 20% as Group 3 and PVCs more than 20% as Group 4.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eComparison of Index and Recurrent PVC Source Locations\u003c/h2\u003e \u003cp\u003eFor statistical analysis, PVC locations were grouped into the following categories: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) right ventricular outflow tract (RVOT), (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) left ventricular outflow tract (LVOT), and coronary cusps.\u003c/p\u003e \u003cp\u003eThe iCEB was determined by pre-procedure resting ECG of patients without PVCs. All measurements were performed using MUSE software (GE Healthcare). The 12-lead ECGs were recorded at a gain of 10 mm/mV and a paper speed of 25 mm/s at rest in the supine position; QRS duration, QT interval, and heart rate were determined. Measurements were made at lead II and lead V5, and the longest QT interval was selected for analysis. The QT interval was corrected using Bazett\u0026rsquo;s formula (QTc\u0026thinsp;=\u0026thinsp;QT/(RR1/2)). The iCEB and corrected iCEB (iCEBc) were calculated; the iCEB by dividing QT by QRS duration, and iCEBc by dividing QTc by QRS duration. iCEB was calculated from pre-procedural ECGs of patients without PVCs.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eHere, SPSS 28.0 Statistical Package for Windows (SPSS Inc., Chicago, IL, USA) was used. The Kolmogorov\u0026ndash;Smirnov test was used to determine the distribution pattern of the parameters. Continuous parameters with normal distribution are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation, parameters with non-normal distribution are presented as median, and categorical variables are presented as numbers and percentages. Analysis of variance tests or Kruskal\u0026ndash;Wallis tests were used to compare continuous variables according to iCEB groups. The chi-squared (χ\u003csup\u003e2\u003c/sup\u003e) test was used to compare categorical variables. Multivariate logistic regression analysis was used to identify independent parameters associated with \u0026gt;\u0026thinsp;20% PVCs.\u003c/p\u003e \u003c/div\u003e"},{"header":"RESULTS","content":"\u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e shows the demographic, clinical, and laboratory characteristics of the study population. There were no significant differences between the groups in terms of cardiovascular risk factors, including age, gender, coronary artery disease, diabetes, or hypertension. Statin and diuretic use and platelet levels were significantly lower in the highest PVC group than in the other groups; EF was similar between groups.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eDemographic, clinical, and laboratory characteristics of the study population. ACEI: angiotensin converting enzyme inhibitor; ALT: alanine transaminase; ARB: angiotensin receptor blocker; AST: aspartate transferase; EF: ejection fraction; GFR: glomerular filtration rate; LV: left ventricle; WBC: white blood cell. Bold values indicate statistical significance at the p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 level.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 1 (\u0026le;\u0026thinsp;5% PVCs) (n\u0026thinsp;=\u0026thinsp;75)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 2 (\u0026gt;\u0026thinsp;6% and \u0026le;\u0026thinsp;10% PVCs) (n\u0026thinsp;=\u0026thinsp;8)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 3 (\u0026gt;\u0026thinsp;11% and \u0026le;\u0026thinsp;20% PVCs) (n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 4 (\u0026gt;\u0026thinsp;20% PVCs) (n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e53.5\u0026thinsp;\u0026plusmn;\u0026thinsp;14.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e52.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e55.8\u0026thinsp;\u0026plusmn;\u0026thinsp;13.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e55.3\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.964\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e34 (45.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (37.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.483\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHypertension, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e41 (54.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 (55.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.955\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDiabetes mellitus, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20 (26.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (44.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.434\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCoronary artery disease, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e28 (37.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (37.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 (77.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.077\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedication, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eACEI/ARB, n(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e38 (50.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (75)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 (77.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.292\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBeta blocker, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e62 (82.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 (62.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 (83.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 (88.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.617\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eStatin, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18 (24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (37.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.010\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDiuretic, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e6 (\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (37.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (22.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.021\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHemoglobin (g/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.4(9.6;17.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.1 (10.0;15.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.2 (12.8;16.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13.5 (11.2;16.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.729\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWBC (10\u003csup\u003e3\u003c/sup\u003e/\u0026micro;L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.609\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePlatelets (10\u003csup\u003e3\u003c/sup\u003e/\u0026micro;L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e254\u0026thinsp;\u0026plusmn;\u0026thinsp;62.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e264\u0026thinsp;\u0026plusmn;\u0026thinsp;90.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e213\u0026thinsp;\u0026plusmn;\u0026thinsp;65.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e200\u0026thinsp;\u0026plusmn;\u0026thinsp;26.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.046\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCreatinine (mg/dL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.79(0.48;1.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.78(0.50;1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.83(0.65;1.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.93(0.74;1.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.262\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGFR (mL/min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e90.8\u0026thinsp;\u0026plusmn;\u0026thinsp;21.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e92.5\u0026thinsp;\u0026plusmn;\u0026thinsp;17.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e85.6\u0026thinsp;\u0026plusmn;\u0026thinsp;27.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e86.3\u0026thinsp;\u0026plusmn;\u0026thinsp;24.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.872\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSodium (mmol/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e140\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e140.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e139\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e138\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.123\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePotassium (mmol/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.175\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCalcium (mg/dL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e9.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.626\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAST (U/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19(10;76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16(12;31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16.5(15;21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20(9;97)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.389\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eALT (U/L)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17(5;159)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16(9;33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e16(10;37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15(9;34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.933\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLV EF(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60 (55;68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e62(60;65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60(58;65)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e60(55;68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.149\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eACEI: angiotensin converting enzyme inhibitor; ALT: alanine transaminase; ARB: angiotensin receptor blocker; AST: aspartate transferase; EF: ejection fraction; GFR: glomerular filtration rate; LV: left ventricle; WBC: white blood cell. Bold values indicate statistical significance at the p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 level.\u003c/p\u003e\n\u003cp\u003eThe patients\u0026rsquo; ECG parameters are presented in Table \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e. QRS duration was significantly different between groups, with Group 4 having the highest duration (p\u0026thinsp;=\u0026thinsp;0.004). There was no difference in QT duration; however, iCEB and iCEBc were significantly lower in the highest PVC group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab3\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eElectrocardiographic parameters of the groups. iCEB: index of cardio-electrophysiological balance; iCEBc: corrected index of cardio-electrophysiological balance; ms: millisecond; PVCs: premature ventricular complexes; QTc: corrected QT interval. Bold values indicate statistical significance at the p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 level.\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 1 (\u0026le;\u0026thinsp;5% PVCs) (n\u0026thinsp;=\u0026thinsp;75)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 2 (\u0026gt;\u0026thinsp;6% and \u0026le;\u0026thinsp;10% PVCs) (n\u0026thinsp;=\u0026thinsp;8)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 3 (\u0026gt;\u0026thinsp;11% and \u0026le;\u0026thinsp;20% PVCs) (n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGroup 4 (\u0026gt;\u0026thinsp;20% PVCs) (n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eQRS interval (ms)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e84(66\u0026ndash;144)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e90(70\u0026ndash;110)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e85(74\u0026ndash;98)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e110(78\u0026ndash;162)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.004\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eQT interval (ms)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e391\u0026thinsp;\u0026plusmn;\u0026thinsp;29.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e382\u0026thinsp;\u0026plusmn;\u0026thinsp;30.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e405\u0026thinsp;\u0026plusmn;\u0026thinsp;27.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e404\u0026thinsp;\u0026plusmn;\u0026thinsp;32.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.294\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eQTc interval (ms)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e438(377\u0026ndash;495)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e430.5(400\u0026ndash;445)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e450(375\u0026ndash;458)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e437(395\u0026ndash;525)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.550\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eiCEB (QT/QRS ratio)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u0026thinsp;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eiCEBc (QTc/QRS ratio)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;\u0026thinsp;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eWhen we performed multiple backward logistic regression analyses with a model including age, platelets and iCEBc, a lower iCEBc (p\u0026thinsp;=\u0026thinsp;0.003) was associated with higher PVCs (Table \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eCI : confidence interval, iCEBc: corrected index of cardio-electrophysiological balance, OR: odds ratio\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab4\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eLogistic regression analysis of potential predictor factors for premature ventricular complexes burden\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"3\"\u003e\n \u003cp\u003eUnivariate analysis\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"3\"\u003e\n \u003cp\u003eMultivariate analysis\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eOR\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e95%CI\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eOR\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003e95%CI\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep value\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.986\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.946\u0026ndash;1.028\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.508\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCoronary artery disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.161\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.214\u0026ndash;6.293\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.862\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eStatin use\u003c/p\u003e\n \u003cp\u003eiCEBc\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e5.942\u003c/p\u003e\n \u003cp\u003e0.353\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.180-29.918\u003c/p\u003e\n \u003cp\u003e0.176\u0026ndash;0.707\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.031\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e0.003\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.384\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.204\u0026ndash;0.723\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.003\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eReceiver operating characteristic analysis revealed that an iCEBc value of 4.87 had 72% specificity and 65.2% sensitivity for predicting PVC burden following PVC catheter ablation (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eWe aimed to determine the relationship between the iCEBc in patients with structurally normal hearts and post-catheter ablation PVC burden in patients undergoing PVC catheter ablation. Here, iCEBc was significantly associated with post-ablation PVC burden independently, with significantly lower iCEBc values. To the best of our knowledge, this is the first study to investigate the relationship between iCEBc and PVC burden following PVC catheter ablation.\u003c/p\u003e \u003cp\u003eAlthough PVCs are common and generally thought to be harmless, many studies show a higher risk for all-cause and cardiovascular mortality in patients without structural heart disease (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). It is now known that PVCs are potentially dangerous to susceptible patients and can occur as triggers of VF and sudden cardiac death. Alternatively, frequent ventricular extrasystoles can also cause cardiomyopathy (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). However, the mechanism by which PVCs trigger VF in a structurally normal heart remains unclear (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe iCEB, the ratio of QT to QRS (QT/QRS) calculated from surface ECG, is a simple ECG marker that can predict ventricular arrhythmogenesis. The iCEB is equivalent to the cardiac wavelength λ, which is measured via invasive electrophysiological study and plays an important role in ventricular arrhythmias. Previous studies have suggested that the iCEB may offer a non-invasive and easily measurable marker to detect increased arrhythmic risk in patients (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Increased or decreased values of iCEB are associated with ventricular arrhythmic events (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Furthermore, iCEB is associated with long QT and TdP, but also with QT shortening and associated non-TdP-like VT/VF (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Due to its non-invasive nature and ease of measurement, it has attracted great interest in clinical practice. Recently, iCEB has been found to be a better predictor of arrhythmia risk compared to the Tp-e interval, QTc interval, and Tp-e/QTc ratio (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). In a study by Adali et al., iCEBc was found to be a marker that can predict PVCs in patients without structural heart disease (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Our study found that iCEBc can predict PVC burden following PVC catheter ablation.\u003c/p\u003e \u003cp\u003eQT and QTc intervals include periods of ventricular depolarization and repolarization, and their prolongation poses a risk for malignant ventricular arrhythmias (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Our study found no significant difference in QT and QTc intervals. There is very little information about QRS complex dispersion. One study found that QRS duration and dispersion were significantly higher in AMI-related precursors. QRS dispersion was the ECG variable more closely associated with the occurrence of VT and VF, and it also suggested that the likelihood of ventricular arrhythmias is much higher when QRS duration and dispersion are high rather than when QTc duration and dispersion are high (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). In our study, prolonged QRS duration was found to be statistically significantly higher with PVC burden following PVC catheter ablation.\u003c/p\u003e \u003cp\u003eIt has been suggested that increased iCEB may trigger a TdP-mediated arrhythmogenic effect, whereas decreased iCEB may cause non-TdP arrhythmias. Furthermore, sotalol use and congenital long QT syndrome, TdP-related arrhythmias, increased both iCEB and iCEBc. In contrast, Brugada syndrome and flecainide use, non-TdP ventricular arrhythmias, decreased iCEB and iCEBc (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). In our study, iCEB and iCEBc values were significantly lower in the group with a higher PVC burden.\u003c/p\u003e"},{"header":"LIMITATIONS","content":"\u003cp\u003eOur study has a few limitations. First, this is a single-center study involving a smaller number of patients. Second, the patients were not followed up, and the PVC burden was only determined once. Thirdly, a prospective study is essential for clinical events, such as malignant ventricular arrhythmias and sudden cardiac death. Fourtly only two PVC localizations were included in the study. The results may change with the inclusion of other localizations. Finally, the validity of the iCEB values must be correlated with the cardiac wavelength λ measurement determined by the electrophysiological study.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThe iCEBc is a novel, non-invasive marker that can predict PVC burden following PVC catheter ablation in patients with structurally normal hearts. Beyond other ECG parameters, the iCEBc can be used as an accurate marker of electrophysiologic balance and arrhythmia risk.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Not applicable.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCO \u0026nbsp;conceived and designed the research. IZ, AY analyzed the data and drafted the manuscript. BU, IZ, AY collected the data and performed the research. CO,BU reviewed and edited the manuscript and approved the final version of the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study protocol was approved by local ethics committee and was conducted according to the principles of the Declaration of Helsinki. Written informed consent could not be obtained from the patients due to the retrospective design of the study (Institutional Ethics Committee (decision no: 2024-2 / 2, date: 21.02.2024).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eZhang Y-T, Li H-Y, Sun X-T, Tong X-W, Shan Y-Y, Xu Y-X, et al. Relationship between index of cardiac electrophysiological balance, frontal qrs-t angle and retinopathy in people with type 2 diabetes. Metabolic Syndrome and Obesity: Diabetes; 2023. pp. 861\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eProclemer A, Dagres N, Marinskis G, Pison L, Lip GY, Blomstrom-Lundqvist C, et al. Current practice in Europe: how do we manage patients with ventricular tachycardia? European Heart Rhythm Association survey. Europace. 2013;15(2):167\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCantillon DJ. of premature ventricular complexes. Cleve Clin J Med. 2013;80(6):377.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarcus GM. Evaluation and management of premature ventricular complexes. Circulation. 2020;141(17):1404\u0026ndash;18.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAdali MK, Davutoglu Y, Yilmaz S. The relationship between premature ventricular complexes and index of cardiac-electrophysiological balance. Revista da Associa\u0026ccedil;\u0026atilde;o M\u0026eacute;dica Brasileira. 2023;69:142\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBerruezo A, Penela D, J\u0026aacute;uregui B, Soto-Iglesias D, Aguinaga L, Ord\u0026oacute;\u0026ntilde;ez A, et al. Mortality and morbidity reduction after frequent premature ventricular complexes ablation in patients with left ventricular systolic dysfunction. EP Europace. 2019;21(7):1079\u0026ndash;87.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLatchamsetty R, Yokokawa M, Morady F, Kim HM, Mathew S, Tilz R, et al. Multicenter outcomes for catheter ablation of idiopathic premature ventricular complexes. JACC: Clin Electrophysiol. 2015;1(3):116\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY\u0026uuml;cetas SC, Kaya H, Kafadar S, Kafadar H, Tibilli H, Akcay A. Evaluation of index of cardiac-electrophysiological balance in patients with subarachnoid hemorrhage. BMC Cardiovasc Disord. 2022;22(1):1\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRobyns T, Lu HR, Gallacher DJ, Garweg C, Ector J, Willems R, et al. Evaluation of index of cardio-electrophysiological balance (iCEB) as a new biomarker for the identification of patients at increased arrhythmic risk. Ann Noninvasive Electrocardiol. 2016;21(3):294\u0026ndash;304.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuebbert J, Auberson D, Marchlinski F. Premature ventricular complexes in apparently normal hearts. Cardiac Electrophysiol Clin. 2016;8(3):503\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOomen A, Dekker L, Meijer A. Catheter ablation of symptomatic idiopathic ventricular arrhythmias: A five-year single-centre experience. Neth Heart J. 2018;26:210\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBikkina M, Larson MG, Levy D. Prognostic implications of asymptomatic ventricular arrhythmias: the Framingham Heart Study. Ann Intern Med. 1992;117(12):990\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIp JE, Lerman BB. Idiopathic malignant premature ventricular contractions. Trends Cardiovasc Med. 2018;28(4):295\u0026ndash;302.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAfsin A, Asoglu R, Kobat MA, Asoglu E, Suner A. Evaluation of index of cardio-electrophysiological balance in patients with atrial fibrillation on antiarrhythmic-drug therapy. Cardiol Res. 2021;12(1):37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003e\u0026Ouml;zdemir L, S\u0026ouml;kmen E. Effect of habitual cigarette smoking on the index of cardiac electrophysiological balance in apparently healthy individuals. J Electrocardiol. 2020;59:41\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu HR, Yan G-X, Gallacher DJ. A new biomarker\u0026ndash;index of Cardiac Electrophysiological Balance (iCEB)\u0026ndash;plays an important role in drug-induced cardiac arrhythmias: beyond QT-prolongation and Torsades de Pointes (TdPs). J Pharmacol Toxicol Methods. 2013;68(2):250\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLim TR, Rangaswami AA, Dubin AM, Kapphahn KI, Sakarovitch C, Long J, et al. QTc prolongation and risk of torsades de pointes in hospitalized pediatric oncology patients. J Pediatr. 2020;217:33\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCh\u0026aacute;vez-Gonz\u0026aacute;lez E, Jim\u0026eacute;nez AR, Moreno-Mart\u0026iacute;nez F. QRS duration and dispersion for predicting ventricular arrhythmias in early stage of acute myocardial infraction. Med Intensiva (English Edition). 2017;41(6):347\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAskin L, Tanrıverdi O. Evaluation of index of cardio-electrophysiological balance in patients with coronary slow flow. Acta Cardiol. 2022;77(4):337\u0026ndash;41.\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":false,"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":"Cardiac-Electrophysiologic Balance Index, Catheter Ablation, Premature Ventricular Complexes","lastPublishedDoi":"10.21203/rs.3.rs-4559507/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4559507/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackround\u003c/h2\u003e \u003cp\u003eSudden cardiac death due to ventricular tachyarrhythmias is a global concern. Electrocardiogram (ECG) parameters can predict ventricular arrhythmias. Premature ventricular complexes (PVCs) are common arrhythmias, potentially triggering life-threatening events. The index of cardiac electrophysiological balance (iCEB) is hypothesized to predict arrhythmias. This study aimed to correlate iCEB with PVC burden post-catheter ablation.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eNinety-eight patients without structural heart disease underwent PVC catheter ablation. Successful ablation was defined as PVC elimination without recurrence. iCEB was calculated from resting ECG. Patients were categorized based on PVC burden. Statistical analysis was performed using SPSS.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eNo significant differences in cardiovascular risk factors were found among groups. Lower iCEBc was associated with higher PVC burden. An iCEBc value of 4.87 had 72% specificity and 65.2% sensitivity for predicting PVC burden.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe study suggests that iCEBc is a promising predictor for post-ablation PVC burden, indicating its potential clinical utility. Further research validating these findings and elucidating underlying mechanisms is needed to enhance risk stratification and optimize patient management. Integrating iCEBc assessment into routine practice may aid in identifying high-risk patients and implementing targeted interventions. iCEBc is a non-invasive marker for predicting PVC burden following PVC catheter ablation in patients with structurally normal hearts.\u003c/p\u003e","manuscriptTitle":"The Relationship Between Premature Ventricular Complexes Burden and Cardiac-Electrophysiologic Balance Index After Premature Ventricular Complex Catheter Ablation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-18 20:52:57","doi":"10.21203/rs.3.rs-4559507/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":"08f6b525-c77b-4958-86a3-209b59fba286","owner":[],"postedDate":"July 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-12-18T06:24:05+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-18 20:52:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4559507","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4559507","identity":"rs-4559507","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}