Epidemiology, clinical characteristics and life-threatening risk profile of WPW in children: 30 years population follow up at a single centre in South Wales

Epidemiology, clinical characteristics and life-threatening risk profile of WPW in children: 30 years population follow up at a single centre in South Wales | 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 Epidemiology, clinical characteristics and life-threatening risk profile of WPW in children: 30 years population follow up at a single centre in South Wales Orhan Uzun, Derya Duman, Gulhan Tunca Sahin, Yasemin Nuran Donmez, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4803843/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 Backgrounds and Aims : This study aims to assess the epidemiology, clinical presentation, management, and outcomes of pediatric Wolff-Parkinson-White (WPW) syndrome, as well as the incidence of life-threatening events (LTE) in South Wales. Methods retrospective review of patients (< 17 years old) diagnosed with WPW syndrome between 1986 and 2019 in South Wales. Results The study population consisted of 160 patients, of whom 86 (54%) were male. The prevalence of WPW syndrome was 0.028%. Thirty percent of cases were diagnosed during infancy, while 63% presented after aged 5. Incidental diagnosis occurred in 47 (29,3%) asymptomatic patients. Spontaneous resolution of delta wave was observed in 19 patients (11.9%). Thirteen children (8.1%, 11 males) presented with an LTE, resulting in an estimated LTE risk of 3.8 per 1000 person-years during childhood in South Wales. Acute management was required in 36% (55/154) of patients, with seven experiencing preexcited atrial fibrillation (4.5%). Among children with preexcited atrial fibrillation and rapid ventricular conduction, only three out of seven children experienced aborted sudden cardiac death (1.9%). No deaths directly attributable to isolated WPW and related arrhythmia were recorded. Conclusions Asymptomatic WPW in children demonstrated a high propensity for life-threatening events in South Wales, prompting a policy shift towards earlier referral for electrophysiology study (EPS) prior to adolescence. These findings underscores the need for more rigorous risk stratification and closer follow-up of all WPW patients, as asymptomatic cases do not guarantee safety. Wolff-Parkinson-White syndrome children atrial fibrillation sudden death Figures Figure 1 Figure 2 Figure 3 What’s New? What is already known on this topic – Historically, asymptomatic patients with WPW and those demonstrating loss of preexcitation on exercise test were considered low risk for life-threatening events (LTE) and managed conservatively by non-electrophysiologists. What this study adds – This study reinforces the observation of a higher incidence of life-threatening events in asymptomatic children with WPW patients in South Wales. Furthermore, it advocates for a more catious approach, suggesting a lower threshold for referring younger children for RF ablation procedures before adolescence. How this study might affect research, practice or policy – The findings of this national study underscores the necessity for closer monitoring of children with WPW syndrome, irrespective of age and symptoms. EPS emerges as the primary method for identifying individuals as high risk of LTE events during the childhood. Introduction Wolff-Parkinson-White (WPW) syndrome, characterized by accessory pathways connecting the atrium and the ventricle, presents a risk of sudden arrhythmic death due to rapid conduction of atrial fibrillation or flutter to the ventricles, resulting in ventricular fibrillation [ 1 ]. Patients who are asymptomatic and those who present with loss of preexcitation on exercise testing have traditionally been considered at low risk for life-threatening events (LTE). However, emerging evidence challenges this perception, suggesting a potential underestimation of risk, particularly in younger populations [ 2 , 3 ]. Yet, no population-based study in the United Kingdom has comprehensively investigated the epidemiology, clinical presentation, and risk of life-threatening events associated with WPW syndrome. Therefore, this study aims to fill this gap by evaluating these aspects among pediatric WPW patients at a tertiary cardiac center in South Wales. Methods A retrospective review was conducted on 160 patients under 17 years old diagnosed with WPW syndrome between 1986 and 2019 in South Wales. Patient data were sourced from hospital medical records and departmental digital databases. Collected data encompassed patient demographics, presence of associated heart disease, clinical presentation, documented arrhythmias, persistence or intermittence of preexcitation, spontaneous resolution of manifest preexcitation, findings from invasive electrophysiology studies (EPS), and clinical events during follow-up. Noninvasive risk stratification included Holter monitoring and/or exercise stress testing to demonstrate loss of ventricular preexcitation. EPS data comprised accessory pathway (AP) location(s), AP conduction properties, and induction of tachycardia. High-risk APs were defined as having specific criteria for antegrade AP effective refractory period (APERP), shortest pre-excited paced cycle length (SPPCL) during atrial pacing, or shortest pre-excited RR interval in atrial fibrillation (SPERRI) ≤ 250 ms at invasive EPS [ 2 ]. Ablation outcomes and complications were documented. Non-persistent pre-excitation was defined as intermittent absence of ventricular preexcitation on electrocardiography (ECG) or Holter monitoring or sudden loss during exercise stress testing. Life-threatening events (LTE) were classified as sudden death, aborted sudden death, or clinical episodes of pre-excited atrial fibrillation associated with or without hemodynamic compromise, syncope, or seizure. Atrial flutter (AF) causing hemodynamic compromise and necessitating intubation for acute DC cardioversion was also considered a life-threatening manifestation of WPW syndrome in fetuses and infants. Data were tabulated, grouped, and analyzed using descriptive statistics. The population prevalence of WPW syndrome was determined by dividing the number of subjects in the study cohort by the total number of subjects aged 1–17 years in the database over the study period in South Wales. Statistic Methods Data analysis was performed using IBM SPSS Statistics 22 (IBM SPSS, UK). Normality of parameters was assessed using the Shapiro-Wilk test. Descriptive statistics (mean, standard deviation, frequency) were employed for data evaluation. For comparisons of normally distributed quantitative data between two groups, the Student t-test was used, while the Mann-Whitney U test was applied for non-normally distributed parameters. The Chi-square test, Fisher’s Exact test, Fisher Freeman Halton test, and Continuity (Yates) Correction were utilized for qualitative data comparisons. Multivariate analysis was conducted using logistic regression analysis. Survival time comparisons among age groups were performed using the Log-Rank (Mantel-Cox) test, with the impact of age groups on survival further investigated through Cox regression analysis. A significance level of p < 0.050 was considered. Ethics standards As the data were collected and recorded as part of routine clinical practice for periodic service evaluation, a specific ethical approval application was deemed unnecessary. Both the Health Research Authority of the United Kingdom and the South Wales Ethics Committee confirmed that reviews of this nature do not require ethics approval. Before retrospective analysis, all collected information was anonymized. Additionally, all authors held official contracts as visiting research fellows with the University Hospital of Wales during the review and analysis period. All procedures pertaining to this review adhered to the principles outlined in the Declaration of Helsinki. Results Demographic and clinical data Over a 30-year period, 160 patients were included in the study, with 54% being male. The childhood prevalence of WPW syndrome was 0.028% (160/562,730). Diagnosis occurred during infancy in 30% of cases, with 21% diagnosed in neonates, while 63% were diagnosed after 5 years of age (Fig. 1 ). Incidental diagnosis was noted in 29% of patients who were asymptomatic. The most common presenting symptoms in older children were palpitations at rest (74/160) and on exertion (25/160), followed by dizziness/lightheadedness (34/160) and shortness of breath (19/160). Neonates and infants presented with less specific symptoms such as poor feeding, agitation, and signs of cardiorespiratory compromise. Holter ECG was obtained in 52% of patients (n = 83), with supraventricular tachycardia (SVT) captured in 18% of them. Exercise stress tests were performed in 32.5% of patients (n = 52), with delta wave disappearance noted in 29% during the test (n = 15). Significant structural heart disease was detected in nine patients, including Ebstein anomaly (3), hypertrophic cardiomyopathy (2), Fallot’s tetralogy, ventricular septal defect with pulmonary stenosis, total anomaly pulmonary venous connection, sinus venosus type atrial septal defect with pulmonary stenosis (for each, n = 1). Left ventricular (LV) systolic function was impaired in 13% of patients (n = 21), with 11 infants and 3 neonates. Moreover, 2 patients had hypertrophic cardiomyopathy due to Noonan and Danon syndromes. Spontaneous resolution of delta wave was observed in 12% of patients (n = 19), with only 8.5% of asymptomatic patients experiencing resolution. The distribution according to the age at which spontaneous resolution occurs is shown in Fig. 2 . Data on acute management was available only in 154 patients. Accute management according to the Advanced Paediatric Life Support (APLS) protocol was required in 36% of patients (n = 55), with adenosine administered to 69% of them (n = 38). Among those who received adenosine, 66% (n = 25) responded to treatment, while 8% (n = 13) required cardioversion or further intravenous antiarrhythmic treatment. Electrophysiology study data Table 1 presents EPS data and ablation outcomes. Of the 101 patients (63%) who underwent EPS and ablation procedures, 18 (18%) had multiple accessory pathways (APs), with a slight majority located on the right side (52.5%). Notably, ablation of single right APs (27%) failed twice as often as that of single left-sided ones (13.5%). Table 1 Baseline EPS data and ablation outcomes Asymptomatic n (%) Symptomatic n (%) Total n (%) p Gender (Male) 28 (%59,6) 58 (%51,3) 86 (%53,8) 2 0,341 Age groups 5 years 27 (%57,4) 74 (%65,5) 101 (%63,1) EPS performed 21 (%44,7) 80 (%70,8) 101 (%63,1) 4 0,002* Ablation performed 17 (%36,2) 79 (%69,9) 96 (%60) 5 0,000* APERP (ms) (n = 60) (Min-Max)-(Ort ± SS) (220–450)- (300 ± 62,82) (180–440)-(297,73 ± 51,75) (180–450)-(298,33 ± 54,37) 1 0,888 SPERRI (ms) (n = 60) (Min-Max)(Ort ± SS) (220–450)-(303,13 ± 64,05) (180–400)-(295 ± 47,03) (180–450)-(297,17 ± 51,65) 1 0,594 Risk stratification n (%) n (%) n (%) LT event 1 (%2.1) 12 (%10,6) 13 (%8,1) 2 0,062 APERP (≤ 250 ms) 13 (%81,3) 35 (%79,5) 48 (%80) 2 0,599 SPERRI (≤ 250ms) 13 (%81,3) 35 (%79,5) 48 (%80) 2 0,599 SVT (ORT) induced 7 (%33,3) 32 (%40) 39 (%38,6) 3 0,759 SVT (ART) induced 1 (%4,8) 0 (%0) 1 (%1) 2 0,208 > 1 accessory pathway 3 (%14,3) 15 (%18,8) 18 (%17,8) 2 0,455 Ablation successful 14 (%61,9) 67 (%71,3) 81 (%84,4) 3 0,575 Procedure Complication 1 (%4,8) 4 (%5) 5 (%5) 2 0,723 Bronchospasm due to adenosine Complete AV block Pericardial laceration Pericardial puncture 1 (%100) 0 (%0) 1 (%25) 0 (%0) 1 (%33,3) 1 (%25) 0 (%0) 1 (%33,3) 1 (%25) 0 (%0) 1 (%33,3) 1 (%25) 1 Student t Test 2 Fisher’s Exact Test 3 Continuity (Yates) Correction 4 Chi-Square Test 5 Fisher Freeman Halton Test *p < 0.05 APERP = accessory pathway effective refractory period, ART = antidromic reciprocating tachycardia, EPS = electrophysiology study, LTE = life-threatening event, ORT = orthodromic reciprocating tachycardia, SPERRI = shortest pre-excited RR interval in atrial fibrillation, SVT = supraventricular tachycardia Among patients with multiple APs (n = 14), 78% had a failed initial attempt of ablation. Moreover, 4 patients with postero-septal pathways and 1 with a pathway in the middle cardiac vein also had a failed first ablation. Sixty-seven percent (n = 22) of patients with failed ablations underwent repeat EPS, with 18.2% (n = 4) experiencing unsuccessful repeat ablation. The overall success rate with EPS, including repeat ablations, was 84.4%. Comparison of EPS data between symptomatic and asymptomatic groups revealed no significant differences in mean APERP, SPERRI, or SPPCL values (Table 1 ). Similarly, there were no differences in the proportions of both groups with APERP, SPERRI values of ≤ 250 ms, multiple accessory pathways, procedural success rate, or complications. The rate of potentially dangerous pathways with short APERP and SPERRI (≤ 250 ms) was similar in symptomatic and asymptomatic patients (P = 0.599). EPS identified right APs in seven patients, left APs in five patients, more than one AP in six patients, and parahisian AP in two asymptomatic patients. Table 1 summarizes AP characteristics of both asymptomatic and symptomatic patients. Outcomes Thirteen children (8%, 84.6% male) experienced life-threatening events (LTE), with five ≤ one month old. The total LTE frequency was 3.8 events per 1000 person-years in the South Wales child population. Seven patients required cardioversion due to pre-excited atrial fibrillation (AF) or flutter, resulting in a pre-excited AF risk rate of 2 events per 1000 person-years. Among patients with pre-excited AF and rapid ventricular conduction, three experienced aborted sudden cardiac death (1.9%). Three asymptomatic children had their first presentation with pre-excited AF, with a risk rate of 1.7 per 1000 person-years. LTE predominantly occurred at rest or with non-competitive activity (n = 11, 84.6%). Table 2 outlines case subject characteristics and LTE details, with LTE being the first presentation in 11 cases, none of whom had previous symptoms or were known to have WPW. Table 2 Presentation, management, and outcome of life-threatening events in WPW patients. No Age Sex M/F Clinical presentation Symptoms at presentation Activity Abnormal ECG before LTE** Aborted sudden death, First Treatment Associated Structural / Functional Heart Disease Accessory pathway(s) Outcome 1 1 day M AVRT Yes Non-competitive (rest) First presentation No, CV Severe LV dysfunction - ECG WPW, Awaiting EPS 2 1 day M Pre-excited AF to VF Yes Non-competitive (rest) First presentation No, CV Severe LV dysfunction Left lateral Successful ablation on 1st attempt 3 3 weeks F AVRT Cardiogenic shock Non-competitive (rest) First presentation No, CV - - Controlled off medication (sotalol) 4 1 month M AVRT Cardiogenic shock Non-competitive (rest) First presentation No, CV Moderate LV dysfunction - Spontaneous resolution 5 1 month M AF Cardiogenic shock Non-competitive (rest) First presentation No, CV - - Spontaneous resolution 6 2 months M AF to VF Cardiac arrest Non-competitive (rest) First presentation Yes, CPR, CV TIC with LV dysfunction Left anterolateral Successful ablation on 1st attempt 7 5 years M Pre-excited AF to VF Epilepsy, LOC Aborted sudden cardiac death Non-competitive (rest) Asymptomatic WPW Yes, CPR, CV - Left coronary sinus Right posterior Successful ablation on 2nd attempt 8 7 years M AVRT Cardiovascular collapse Competitive (football) First presentation No, Spontaneous recovery - Left sided Successful ablation on 1st attempt 9 9 years M Pre-excited AF to VF Cardiovascular collapse Non-competitive (walking) First presentation No, Spontaneous recovery - Right posteroseptal Successful ablation on 2nd attempt 10 14 years M Pre-excited AF to VF Cardiovascular collapse Competitive (football) First presentation Yes, CPR, CV - Left sided coronary sinus diverticulum Successful ablation on 1st attempt 11 15 years M Pre-excited AF to VF Partial seizure Cardiovascular collapse Non-competitive (walking) First presentation No, Spontaneous recovery - Parahisian Successful ablation on 1st attempt 12 15 years M Pre-excited AF to VF Cardiovascular collapse Non-competitive (rest) First presentation No CV - Right anterolateral Successful ablation on 2nd attempt 13 15 years F Pre-excited AF to VF Cardiovascular collapse Non-competitive First presentation No CV - Left lateral Left mid-septal Successful ablation on 2nd attempt AF: Atrial fibrillation CPR: Cardiopulmonary Resuscitation CV: Cardioversion, ECG: Electrocardiography, EPS: Electrophysiological Study,, F: Female, LOC : Loss of consciousness LTE: Life-threatining Event, M: Male, SVT: supraventricular tachycardia, VF: Ventrivular fibrillation, VT: Ventricular Tachycardia,, WPW: Wolff Parkinson White Syndrome. When comparing LTE survival time across age groups, no significant difference was found (p = 0.339). However, patients in the > 5 years age group had a 1.9 times higher risk of cardiac death compared to the 0–1 year age group, although not statistically significant (p = 0.343) (Table 3 and Fig. 3 ). Notably, five patients presenting with pre-excited AF were in the > 5 years age group. Table 4 summarizes and compares findings among neonates, infants, and others. Table 3 Comparing the survival time for LTE by age groups and examining the effect of age LTE number p Average survival time (%95 CI) HR (%95 CI) p 0–1 year* 6 0,339 16,212 (14,861 − 17,563) 1,881 (0,509–6,943) 0,343 > 5 years 7 14,515 (12,18 − 16,85) Overall 13 15,721 (14,533 − 16,909) Table 4 Characteristics of the patients with WPW according to the age groups. Neonates n: 34 Infants ( 1 year old) n: 112 First presentation LTE, n 3 3 7 Asymptomatic patients, n 6 12 29 Pre-excited AF, n 1 none 6 Decreased LV function, n 3 11 7 Spontaneous resolution, n 12 6 1 AF: Atrial Fibrillation, LTE: Life threatening event, N: Number, WPW: Wolff Parkinson White Syndrome. Complete clinical recovery occurred in all cases of cardiac failure except for one subject who experienced acute kidney failure post-LTE, necessitating kidney transplantation in their teenage years. No deaths attributable to WPW or related arrhythmias were recorded in this cohort. However, one patient with pre-excitation and documented arrhythmia from neonatal to teenage years died following heart transplantation due to severe myocardial failure secondary to Danon disease. Discussion This study represents the largest epidemiological investigation of children with WPW syndrome in the UK, offering valuable insights into prevalence and LTE. Our findings reveal a WPW prevalence of 0.028% among children in South Wales, aligning closely with similar studies globally [ 3 ]. Notably, 8.1% of children presented with LTE, indicating a considerable risk of 3.8 events per 1000 patient-years, consistent with prior research [ 3 – 6 ]. Undoubtedly, the true incidence of WPW among children may be underestimated, considering asymptomatic cases and undocumented sudden cardiac deaths. However, these omissions are unlikely to significantly alter prevalence estimates. We observed a higher LTE risk in males (ratio 5 to 1), consistent with existing literature, despite comparable pre-excitation occurrence in both sexes [ 4 ]. Historically, asymptomatic WPW was considered benign, but emerging evidence challenges this notion. Our study corroborates previous findings, suggesting LTE risk in asymptomatic patients with SCD as the initial presentation [ 7 ]. In this regard, Sarubbi et all [ 8 ] reported that 30% of initially asymptomatic individuals develop symptoms over a-12 year follow-up period, A recent meta-analysis reported the overall risk of SCD for asymptomatic WPW patients at 0.85 events per 1000 person-years. It should be emphasized here that out-of-hospital mortality was not represented in this analysis. While strenuous activities are commonly associated with an elevated LTE risk, it's noteworthy that sports restrictions alone would not have averted all LTE occurrences. A recent study revealed that 73% of LTEs did not occur during any competitive activity [ 2 ], aligning with our findings where the majority of LTEs (85%) occurred without competitive engagement. These observations echo previous reports highlighting that children with pre-excitation are susceptible to LTEs even during periods of rest or minimal activity [ 9 – 11 ]. Our cohort also revealed instances where atrial flutter in neonates with WPW led to cardiovascular collapse, emphasizing the severity of such events. Consequently, we advocate for including atrial flutter in the definition of life-threatening events (LTE) among children with WPW. A striking case in our study involved a 5-year-old boy with asymptomatic preexcitation who suffered an episode of aborted SCD due to rapid conduction of AF during follow-up, necessitating cardiopulmonary resuscitation (CPR) with cardioversion. Remarkably, this child was also known to have epileptic seizures, raising the possibility that these seizures could have been triggered by unrecognized arrhythmic events. This case underscores the critical importance of meticulously evaluating electrocardiograms (ECGs) in children with unexplained or atypical epileptic seizures. It is also well known that ventricular pre-excitation can have detrimental effects on systolic function over time due to abnormal depolarization and repolarization of the myocardium. Accessory pathways can disrupt the typical sequence of ventricular activation, potentially leading to ventricular dyssynchrony, with higher impact for the right free wall and posterior septum locations [ 12 ]. Studies have demonstrated that ablation of these accessory pathways can restore normal ventricular function during follow-up [ 13 – 15 ]. Consistent with these findings, our study observed that impaired left ventricular systolic function in all 18 patients (11.2%) returned to normal ranges following ablation. Even if spontaneous resolution of WPW is a possibility, it is only observed in the minority of patients above the first year of life. [ 6 ]. Moreover, it remains crucial to follow up with these patients, as pre-excitation can re-emerge in 30% around the age of 8 years. [ 16 ] In our study, pre-excitation re-emerged 12 years after diagnosis in one case. In another case, there was no evidence of a delta wave on 12-lead ECG, Holter, and exercise tests throughout childhood, but preexcitation manifested at 25 years of age with SVT. The utilization of electrophysiology studies to assess the risk associated with accessory pathways has traditionally centered on parameters like accessory pathway effective refractory period (APERP), shortest pre-excited R-R Interval during atrial pacing (SPERRI-Ap), and shortest pre-excited R-R interval during atrial fibrillation (SPERRI-AF) [ 17 ]. However, it's increasingly evident that there are no definitive cutoffs in these non-invasive/invasive risk markers that guarantee 100% sensitivity. Consequently, patients with accessory pathways deemed low-risk based on benign conduction properties measured during electrophysiology studies may still experience life-threatening events (LTEs) [ 2 , 17 , 22 ]. A recent large multicenter study underscored this concern, revealing that 37% of children with LTEs in the series lacked high-risk accessory pathway characteristics during electrophysiology studies [ 2 ]. Moreover, when risk stratification was conducted, a study found that clinical SPERRI and SPERRI at EPS exhibited only moderate correlation under anesthesia, with 76.1% of asymptomatic and 55% of symptomatic patients showing this discrepancy [ 2 ]. Etheridge et al. demonstrated that a quarter of patients with a clinically high-risk SPERRI would have been erroneously classified as low-risk [ 2 , 17 ]. Our findings align with this conclusion, as we observed no significant differences in mean APERP, SPERRI, and SPPCL values between patients with multiple accessory pathways and those with asymptomatic pre-excitation. The occurrence rate of potentially hazardous pathways with short APERP was comparable between symptomatic and asymptomatic patients. The majority of patients in our cohort underwent radiofrequency (RF) ablation, with an overall success rate of the initial procedure at a commendable 84.4%, underscoring WPW as a condition largely amenable to cure. Left-sided accessory pathways predominated among patients experiencing LTEs. Notably, four patients necessitated a repeat ablation procedure for successful eradication of the accessory pathways. An important consideration in the ablation treatment of asymptomatic WPW cases is the risk of procedural complications, particularly in paediatric patients. However, a recent study investigating the safety of paediatric ablation in the UK revealed negligible occurrence rates of major complications such as heart block or neurological injury [ 23 ]. Conclusions This study underscores a heightened risk of life-threatening events in asymptomatic children with WPW syndrome in South Wales. Consequently, the findings of this national study emphasize the need for vigilant monitoring of children with WPW, irrespective of age or symptoms. Moreover, our study suggests a more proactive approach to referring younger children for radiofrequency ablation procedures before adolescence. Future national epidemiological studies should focus on establishing safer investigative methods, more reliable risk stratification techniques, and robust follow-up protocols. Given the unreliability of non-invasive risk stratification in WPW patients, electrophysiology study emerges as the primary mechanism for identifying high-risk individuals for life-threatening events during childhood. Study limitations While this study benefits from a robust central database for children in South Wales, its retrospective nature inherently poses limitations. One notable constraint is the inability to capture clinically silent and undiagnosed cases of WPW syndrome, potentially resulting in underrepresentation of the true prevalence. Additionally, the incidence of sudden death or cardiac arrest may have been underestimated due to the unavailability of electrocardiography in such cases. However, we believe the number of unrecognized WPW cases was minimal. Declarations Table 1 Baseline EPS Data and Ablation Outcomes Table 3 Comparing the survival time for LTE by age groups and examining the effect of age Author Contribution OU, as an electrophysiologist, had primary responsibility for confirming the diagnosis of arrhythmia, collecting and facilitating data collection and analysis, writing the manuscript, and critically appraising it. GT, DD, YND, and AABH were clinical/visiting fellows who equally participated in data collection, analysis, statistical evaluation, and drafting the manuscript. MW, AGS, CGC, POC, FL, and OU were the electrophysiologists involved in EPS and ablation procedures at different times, as well as in writing and critically appraising the final manuscript. References Wolff L, Parkinson J, White PD (2006) Bundle-branch block with short P-R interval in healthy young people prone to paroxysmal tachycardia. 1930. Ann Noninvasive Electrocardiol 11(4):340–353 Etheridge SP et al (2018) Life-Threatening Event Risk in Children With Wolff-Parkinson-White Syndrome: A Multicenter International Study. JACC Clin Electrophysiol 4(4):433–444 Janson CM et al (2022) Incidence of life-threatening events in children with Wolff-Parkinson-White syndrome: Analysis of a large claims database. Heart Rhythm 19(4):642–647 Pappone C et al (2003) Usefulness of invasive electrophysiologic testing to stratify the risk of arrhythmic events in asymptomatic patients with Wolff-Parkinson-White pattern: results from a large prospective long-term follow-up study. 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Europace 15(9):1337–1382 Koca S, Akdeniz C, Tuzcu V (2019) Electrophysiological properties of asymptomatic children and adolescents with the Wolff-Parkinson-White electrocardiographic pattern]. Turk Kardiyol Dern Ars 47(8):674–679 Chubb H et al (2019) Management of Asymptomatic Wolff-Parkinson-White Pattern by Pediatric Electrophysiologists. J Pediatr 213:88–95e1 Walsh MA et al (2021) Outcomes From Pediatric Ablation: A Review of 20 Years of National Data. JACC Clin Electrophysiol 7(11):1358–1365 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. 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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-4803843","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":343438448,"identity":"8f4f8e3f-2c08-4032-b9ed-8af256498d9e","order_by":0,"name":"Orhan Uzun","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxUlEQVRIiWNgGAWjYLCCDyDiMOMDMM3AQ4QOxhlgLcyGM4jWwgxWdIBYLQbnz5g9tqmxy+c7zszYwFBjx2Bw5gABLQfOmBvnHEu2nHkYpOVYMoPB2QYCWg72mEnnNjAbGBzmP/6Age0A0F5CDjvMYyZt2VAP1AKy5R8xWo4BtTA2HIZoYWw7QNhhkmfYyiR7jh03kARpSexL5pEk5H2+84e3SfyoqTYAMhgbPnyzk+M7k0DAZSgggbiIHAWjYBSMglFACAAA16NABIh2ORcAAAAASUVORK5CYII=","orcid":"","institution":"University Hospital of Wales, Cardiff University, Swansea University","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Orhan","middleName":"","lastName":"Uzun","suffix":""},{"id":343438449,"identity":"1c64a2ea-4eb2-4b9f-9dd5-8e7c28f8bded","order_by":1,"name":"Derya Duman","email":"","orcid":"","institution":"University Hospital of Wales, Cardiff Universit","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Derya","middleName":"","lastName":"Duman","suffix":""},{"id":343438450,"identity":"b72801bf-7dac-4129-897b-b060aaf27985","order_by":2,"name":"Gulhan Tunca Sahin","email":"","orcid":"","institution":"University Hospital of Wales, Cardiff Universit","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Gulhan","middleName":"Tunca","lastName":"Sahin","suffix":""},{"id":343438451,"identity":"e2b7a0f6-1b9f-4623-b129-7e4ffcabfcb2","order_by":3,"name":"Yasemin Nuran Donmez","email":"","orcid":"","institution":"University Hospital of Wales, Cardiff Universit","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yasemin","middleName":"Nuran","lastName":"Donmez","suffix":""},{"id":343438454,"identity":"614d5610-bbf2-4f6d-b484-c3e5f452d421","order_by":4,"name":"Afzal Abubakker Bapputty Haji","email":"","orcid":"","institution":"University Hospital of Wales","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Afzal","middleName":"Abubakker Bapputty","lastName":"Haji","suffix":""},{"id":343438457,"identity":"690088a3-9698-41b0-8fd5-78c87f155871","order_by":5,"name":"Mark Walsh","email":"","orcid":"","institution":"Bristol Royal Hospital for Children","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Mark","middleName":"","lastName":"Walsh","suffix":""},{"id":343438458,"identity":"63825beb-c43f-45a3-9edf-4830d0fa4bbe","order_by":6,"name":"Cecilia Gonzalez Corcia","email":"","orcid":"","institution":"Bristol Royal Hospital for Children","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Cecilia","middleName":"Gonzalez","lastName":"Corcia","suffix":""},{"id":343438460,"identity":"aa5812c4-95c5-433b-b907-dbdd2aad981c","order_by":7,"name":"Peter O’Callaghan","email":"","orcid":"","institution":"University Hospital of Wales","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Peter","middleName":"","lastName":"O’Callaghan","suffix":""},{"id":343438462,"identity":"064dbb4f-af45-41ab-90b9-dbede4b466ec","order_by":8,"name":"Fong Leong","email":"","orcid":"","institution":"University Hospital of Wales","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Fong","middleName":"","lastName":"Leong","suffix":""},{"id":343438463,"identity":"f0cef1e9-952b-4aeb-9cf6-9ce70e1ef654","order_by":9,"name":"Graham Stuart","email":"","orcid":"","institution":"University Hospital of Wales","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Graham","middleName":"","lastName":"Stuart","suffix":""}],"badges":[],"createdAt":"2024-07-25 19:00:47","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4803843/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4803843/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":63417897,"identity":"5f72ee93-ee79-4eb1-a38f-0ac6e1f45b16","added_by":"auto","created_at":"2024-08-28 02:08:48","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":37248,"visible":true,"origin":"","legend":"\u003cp\u003eAge of presentation of WPW patients in South Wales paediatric population\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4803843/v1/d9263c358976aa92cd22f31b.png"},{"id":63417896,"identity":"7dabe62c-6d97-4431-b24f-90399f0a594c","added_by":"auto","created_at":"2024-08-28 02:08:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":29128,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSpontaenous resolution of WPW according to the age groups at diagnosis.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4803843/v1/8244612bf9b33c242966feb8.png"},{"id":63417895,"identity":"d59dcafa-17c2-4b80-972b-06f17aa8b670","added_by":"auto","created_at":"2024-08-28 02:08:48","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":32703,"visible":true,"origin":"","legend":"\u003cp\u003eSurvival curve by age groups\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4803843/v1/31be163c8c4386e4d1ac007c.png"},{"id":64192991,"identity":"6bd2e8b9-2cf1-4aa7-8fb7-366ada2dd770","added_by":"auto","created_at":"2024-09-09 19:05:49","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":894246,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4803843/v1/380da0e0-bc38-4223-90da-2e767808abf4.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eEpidemiology, clinical characteristics and life-threatening risk profile of WPW in children: 30 years population follow up at a single centre in South Wales \u003c/p\u003e","fulltext":[{"header":"What’s New?","content":"\u003cul type=\"disc\"\u003e\n \u003cli\u003e\u003cstrong\u003eWhat is already known on this topic\u003c/strong\u003e \u0026ndash;\u0026nbsp;\u003cem\u003eHistorically, asymptomatic patients with WPW and those demonstrating loss of preexcitation on exercise test were considered low risk for life-threatening events (LTE) and managed conservatively by non-electrophysiologists.\u0026nbsp;\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWhat this study adds\u003c/strong\u003e \u0026ndash;\u0026nbsp;\u003cem\u003eThis study reinforces the observation of a higher incidence of life-threatening events in asymptomatic children with WPW patients in South Wales. Furthermore, it advocates for a more catious approach, suggesting a lower threshold for referring younger children for RF ablation procedures before adolescence.\u003c/em\u003e\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHow this study might affect research, practice or policy\u003c/strong\u003e \u0026ndash;\u0026nbsp;\u003cem\u003eThe findings of this national study underscores the necessity for closer monitoring of children with WPW syndrome, irrespective of age and symptoms. EPS emerges as the primary method for identifying individuals as high risk of \u0026nbsp;LTE events during the childhood.\u003c/em\u003e\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003eWolff-Parkinson-White (WPW) syndrome, characterized by accessory pathways connecting the atrium and the ventricle, presents a risk of sudden arrhythmic death due to rapid conduction of atrial fibrillation or flutter to the ventricles, resulting in ventricular fibrillation [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Patients who are asymptomatic and those who present with loss of preexcitation on exercise testing have traditionally been considered at low risk for life-threatening events (LTE). However, emerging evidence challenges this perception, suggesting a potential underestimation of risk, particularly in younger populations [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eYet, no population-based study in the United Kingdom has comprehensively investigated the epidemiology, clinical presentation, and risk of life-threatening events associated with WPW syndrome. Therefore, this study aims to fill this gap by evaluating these aspects among pediatric WPW patients at a tertiary cardiac center in South Wales.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eA retrospective review was conducted on 160 patients under 17 years old diagnosed with WPW syndrome between 1986 and 2019 in South Wales. Patient data were sourced from hospital medical records and departmental digital databases. Collected data encompassed patient demographics, presence of associated heart disease, clinical presentation, documented arrhythmias, persistence or intermittence of preexcitation, spontaneous resolution of manifest preexcitation, findings from invasive electrophysiology studies (EPS), and clinical events during follow-up.\u003c/p\u003e \u003cp\u003eNoninvasive risk stratification included Holter monitoring and/or exercise stress testing to demonstrate loss of ventricular preexcitation. EPS data comprised accessory pathway (AP) location(s), AP conduction properties, and induction of tachycardia. High-risk APs were defined as having specific criteria for antegrade AP effective refractory period (APERP), shortest pre-excited paced cycle length (SPPCL) during atrial pacing, or shortest pre-excited RR interval in atrial fibrillation (SPERRI)\u0026thinsp;\u0026le;\u0026thinsp;250 ms at invasive EPS [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Ablation outcomes and complications were documented. Non-persistent pre-excitation was defined as intermittent absence of ventricular preexcitation on electrocardiography (ECG) or Holter monitoring or sudden loss during exercise stress testing.\u003c/p\u003e \u003cp\u003eLife-threatening events (LTE) were classified as sudden death, aborted sudden death, or clinical episodes of pre-excited atrial fibrillation associated with or without hemodynamic compromise, syncope, or seizure. Atrial flutter (AF) causing hemodynamic compromise and necessitating intubation for acute DC cardioversion was also considered a life-threatening manifestation of WPW syndrome in fetuses and infants. Data were tabulated, grouped, and analyzed using descriptive statistics.\u003c/p\u003e \u003cp\u003eThe population prevalence of WPW syndrome was determined by dividing the number of subjects in the study cohort by the total number of subjects aged 1\u0026ndash;17 years in the database over the study period in South Wales.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistic Methods\u003c/h2\u003e \u003cp\u003eData analysis was performed using IBM SPSS Statistics 22 (IBM SPSS, UK). Normality of parameters was assessed using the Shapiro-Wilk test. Descriptive statistics (mean, standard deviation, frequency) were employed for data evaluation. For comparisons of normally distributed quantitative data between two groups, the Student t-test was used, while the Mann-Whitney U test was applied for non-normally distributed parameters. The Chi-square test, Fisher\u0026rsquo;s Exact test, Fisher Freeman Halton test, and Continuity (Yates) Correction were utilized for qualitative data comparisons. Multivariate analysis was conducted using logistic regression analysis. Survival time comparisons among age groups were performed using the Log-Rank (Mantel-Cox) test, with the impact of age groups on survival further investigated through Cox regression analysis. A significance level of p\u0026thinsp;\u0026lt;\u0026thinsp;0.050 was considered.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eEthics standards\u003c/h2\u003e \u003cp\u003eAs the data were collected and recorded as part of routine clinical practice for periodic service evaluation, a specific ethical approval application was deemed unnecessary. Both the Health Research Authority of the United Kingdom and the South Wales Ethics Committee confirmed that reviews of this nature do not require ethics approval. Before retrospective analysis, all collected information was anonymized. Additionally, all authors held official contracts as visiting research fellows with the University Hospital of Wales during the review and analysis period. All procedures pertaining to this review adhered to the principles outlined in the Declaration of Helsinki.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eDemographic and clinical data\u003c/h2\u003e \u003cp\u003eOver a 30-year period, 160 patients were included in the study, with 54% being male. The childhood prevalence of WPW syndrome was 0.028% (160/562,730). Diagnosis occurred during infancy in 30% of cases, with 21% diagnosed in neonates, while 63% were diagnosed after 5 years of age (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Incidental diagnosis was noted in 29% of patients who were asymptomatic. The most common presenting symptoms in older children were palpitations at rest (74/160) and on exertion (25/160), followed by dizziness/lightheadedness (34/160) and shortness of breath (19/160). Neonates and infants presented with less specific symptoms such as poor feeding, agitation, and signs of cardiorespiratory compromise.\u003c/p\u003e \u003cp\u003eHolter ECG was obtained in 52% of patients (n\u0026thinsp;=\u0026thinsp;83), with supraventricular tachycardia (SVT) captured in 18% of them. Exercise stress tests were performed in 32.5% of patients (n\u0026thinsp;=\u0026thinsp;52), with delta wave disappearance noted in 29% during the test (n\u0026thinsp;=\u0026thinsp;15). Significant structural heart disease was detected in nine patients, including Ebstein anomaly (3), hypertrophic cardiomyopathy (2),\u003c/p\u003e \u003cp\u003eFallot\u0026rsquo;s tetralogy, ventricular septal defect with pulmonary stenosis, total anomaly pulmonary venous connection, sinus venosus type atrial septal defect with pulmonary stenosis (for each, n\u0026thinsp;=\u0026thinsp;1). Left ventricular (LV) systolic function was impaired in 13% of patients (n\u0026thinsp;=\u0026thinsp;21), with 11 infants and 3 neonates. Moreover, 2 patients had hypertrophic cardiomyopathy due to Noonan and Danon syndromes.\u003c/p\u003e \u003cp\u003eSpontaneous resolution of delta wave was observed in 12% of patients (n\u0026thinsp;=\u0026thinsp;19), with only 8.5% of asymptomatic patients experiencing resolution. The distribution according to the age at which spontaneous resolution occurs is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eData on acute management was available only in 154 patients. Accute management according to the Advanced Paediatric Life Support (APLS) protocol was required in 36% of patients (n\u0026thinsp;=\u0026thinsp;55), with adenosine administered to 69% of them (n\u0026thinsp;=\u0026thinsp;38). Among those who received adenosine, 66% (n\u0026thinsp;=\u0026thinsp;\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e25)\u003c/span\u003e responded to treatment, while 8% (n\u0026thinsp;=\u0026thinsp;13) required cardioversion or further intravenous antiarrhythmic treatment.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eElectrophysiology study data\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e presents EPS data and ablation outcomes. Of the 101 patients (63%) who underwent EPS and ablation procedures, 18 (18%) had multiple accessory pathways (APs), with a slight majority located on the right side (52.5%). Notably, ablation of single right APs (27%) failed twice as often as that of single left-sided ones (13.5%).\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\u003e\u003cb\u003eBaseline EPS data and ablation outcomes\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\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 \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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAsymptomatic n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSymptomatic n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTotal n (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eGender (Male)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28 (%59,6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e58 (%51,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e86 (%53,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,341\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e\u003cb\u003eAge groups\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;1 month\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (%14,9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e27 (%23,9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e34 (%21,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e\u003csup\u003e3\u003c/sup\u003e0,023*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1 month-1 year\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9 (%19,1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 (%4,4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e14 (%8,8)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1\u0026ndash;5 years\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (%8,5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7 (%6,2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11 (%6,9)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e\u0026gt;\u0026thinsp;5 years\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27 (%57,4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e74 (%65,5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e101 (%63,1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEPS performed\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 (%44,7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e80 (%70,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e101 (%63,1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e4\u003c/sup\u003e0,002*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAblation performed\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17 (%36,2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e79 (%69,9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e96 (%60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e5\u003c/sup\u003e0,000*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAPERP (ms) (n\u0026thinsp;=\u0026thinsp;60)\u003c/b\u003e (Min-Max)-(Ort\u0026thinsp;\u0026plusmn;\u0026thinsp;SS)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(220\u0026ndash;450)- (300\u0026thinsp;\u0026plusmn;\u0026thinsp;62,82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e(180\u0026ndash;440)-(297,73\u0026thinsp;\u0026plusmn;\u0026thinsp;51,75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(180\u0026ndash;450)-(298,33\u0026thinsp;\u0026plusmn;\u0026thinsp;54,37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e1\u003c/sup\u003e0,888\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSPERRI (ms) (n\u0026thinsp;=\u0026thinsp;60)\u003c/b\u003e (Min-Max)(Ort\u0026thinsp;\u0026plusmn;\u0026thinsp;SS)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(220\u0026ndash;450)-(303,13\u0026thinsp;\u0026plusmn;\u0026thinsp;64,05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e(180\u0026ndash;400)-(295\u0026thinsp;\u0026plusmn;\u0026thinsp;47,03)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(180\u0026ndash;450)-(297,17\u0026thinsp;\u0026plusmn;\u0026thinsp;51,65)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e1\u003c/sup\u003e0,594\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRisk stratification\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003en (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003en (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003en (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eLT event\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (%2.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12 (%10,6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13 (%8,1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,062\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAPERP (\u0026le;\u0026thinsp;250 ms)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (%81,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35 (%79,5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48 (%80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,599\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSPERRI (\u0026le;\u0026thinsp;250ms)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13 (%81,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e35 (%79,5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48 (%80)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,599\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSVT (ORT) induced\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (%33,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e32 (%40)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39 (%38,6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e3\u003c/sup\u003e0,759\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSVT (ART) induced\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (%4,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (%0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (%1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,208\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003e\u0026gt;\u0026thinsp;1 accessory pathway\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (%14,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15 (%18,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18 (%17,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,455\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAblation successful\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14 (%61,9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e67 (%71,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e81 (%84,4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e3\u003c/sup\u003e0,575\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eProcedure Complication\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (%4,8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4 (%5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5 (%5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e2\u003c/sup\u003e0,723\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" morerows=\"3\" nameend=\"c2\" namest=\"c1\" rowspan=\"4\"\u003e \u003cp\u003e\u003cb\u003eBronchospasm due to adenosine\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003eComplete AV block\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003ePericardial laceration\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003ePericardial puncture\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (%100)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0 (%0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (%25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"3\" rowspan=\"4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (%0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (%33,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (%25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (%0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (%33,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (%25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (%0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1 (%33,3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (%25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eStudent t Test\u003c/em\u003e \u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eFisher\u0026rsquo;s Exact Test\u003c/em\u003e \u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eContinuity (Yates) Correction\u003c/em\u003e \u003csup\u003e\u003cem\u003e4\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eChi-Square Test\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u003cem\u003e5\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eFisher Freeman Halton Test *p\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eAPERP\u0026thinsp;=\u0026thinsp;accessory pathway effective refractory period, ART\u0026thinsp;=\u0026thinsp;antidromic reciprocating tachycardia, EPS\u0026thinsp;=\u0026thinsp;electrophysiology study, LTE\u0026thinsp;=\u0026thinsp;life-threatening event, ORT\u0026thinsp;=\u0026thinsp;orthodromic reciprocating tachycardia, SPERRI\u0026thinsp;=\u0026thinsp;shortest pre-excited RR interval in atrial fibrillation, SVT\u0026thinsp;=\u0026thinsp;supraventricular tachycardia\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAmong patients with multiple APs (n\u0026thinsp;=\u0026thinsp;14), 78% had a failed initial attempt of ablation. Moreover, 4 patients with postero-septal pathways and 1 with a pathway in the middle cardiac vein also had a failed first ablation. Sixty-seven percent (n\u0026thinsp;=\u0026thinsp;22) of patients with failed ablations underwent repeat EPS, with 18.2% (n\u0026thinsp;=\u0026thinsp;4) experiencing unsuccessful repeat ablation. The overall success rate with EPS, including repeat ablations, was 84.4%.\u003c/p\u003e \u003cp\u003eComparison of EPS data between symptomatic and asymptomatic groups revealed no significant differences in mean APERP, SPERRI, or SPPCL values (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Similarly, there were no differences in the proportions of both groups with APERP, SPERRI values of \u0026le;\u0026thinsp;250 ms, multiple accessory pathways, procedural success rate, or complications. The rate of potentially dangerous pathways with short APERP and SPERRI (\u0026le;\u0026thinsp;250 ms) was similar in symptomatic and asymptomatic patients (P\u0026thinsp;=\u0026thinsp;0.599). EPS identified right APs in seven patients, left APs in five patients, more than one AP in six patients, and parahisian AP in two asymptomatic patients. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes AP characteristics of both asymptomatic and symptomatic patients.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eOutcomes\u003c/h2\u003e \u003cp\u003eThirteen children (8%, 84.6% male) experienced life-threatening events (LTE), with five\u0026thinsp;\u0026le;\u0026thinsp;one month old. The total LTE frequency was 3.8 events per 1000 person-years in the South Wales child population. Seven patients required cardioversion due to pre-excited atrial fibrillation (AF) or flutter, resulting in a pre-excited AF risk rate of 2 events per 1000 person-years. Among patients with pre-excited AF and rapid ventricular conduction, three experienced aborted sudden cardiac death (1.9%). Three asymptomatic children had their first presentation with pre-excited AF, with a risk rate of 1.7 per 1000 person-years. LTE predominantly occurred at rest or with non-competitive activity (n\u0026thinsp;=\u0026thinsp;11, 84.6%). Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e outlines case subject characteristics and LTE details, with LTE being the first presentation in 11 cases, none of whom had previous symptoms or were known to have WPW.\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\u003ePresentation, management, and outcome of life-threatening events in WPW patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\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 \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=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003cp\u003eM/F\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eClinical presentation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSymptoms at presentation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eActivity\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eAbnormal ECG before LTE**\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eAborted sudden death,\u003c/p\u003e \u003cp\u003eFirst Treatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eAssociated Structural / Functional Heart Disease\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003eAccessory pathway(s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003eOutcome\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAVRT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo,\u003c/p\u003e \u003cp\u003eCV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSevere LV dysfunction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eECG WPW,\u003c/p\u003e \u003cp\u003eAwaiting EPS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo,\u003c/p\u003e \u003cp\u003eCV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eSevere LV dysfunction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft lateral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 1st attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 weeks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAVRT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiogenic shock\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo,\u003c/p\u003e \u003cp\u003eCV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eControlled off medication (sotalol)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 month\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAVRT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiogenic shock\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo,\u003c/p\u003e \u003cp\u003eCV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eModerate LV dysfunction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSpontaneous resolution\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 month\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiogenic shock\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo,\u003c/p\u003e \u003cp\u003eCV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSpontaneous resolution\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiac arrest\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes,\u003c/p\u003e \u003cp\u003eCPR, CV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTIC with LV dysfunction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft anterolateral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 1st attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e7\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF Epilepsy, LOC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eAborted sudden cardiac death\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eAsymptomatic WPW\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes,\u003c/p\u003e \u003cp\u003eCPR, CV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft coronary sinus\u003c/p\u003e \u003cp\u003eRight posterior\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 2nd attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e8\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAVRT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCompetitive (football)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo, Spontaneous recovery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft sided\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 1st attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e9\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (walking)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo, Spontaneous recovery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eRight posteroseptal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 2nd attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e10\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCompetitive (football)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eYes,\u003c/p\u003e \u003cp\u003eCPR, CV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft sided coronary sinus diverticulum\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 1st attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e11\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF Partial seizure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (walking)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo, Spontaneous recovery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eParahisian\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 1st attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e12\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive (rest)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo CV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eRight anterolateral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 2nd attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003e13\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePre-excited AF to VF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCardiovascular collapse\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eNon-competitive\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFirst presentation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNo CV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eLeft lateral\u003c/p\u003e \u003cp\u003eLeft mid-septal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eSuccessful ablation on 2nd attempt\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"11\"\u003eAF: Atrial fibrillation CPR: Cardiopulmonary Resuscitation CV: Cardioversion, ECG: Electrocardiography, EPS: Electrophysiological Study,, F: Female, LOC : Loss of consciousness LTE: Life-threatining Event, M: Male, SVT: supraventricular tachycardia, VF: Ventrivular fibrillation, VT: Ventricular Tachycardia,, WPW: Wolff Parkinson White Syndrome.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eWhen comparing LTE survival time across age groups, no significant difference was found (p\u0026thinsp;=\u0026thinsp;0.339). However, patients in the \u0026gt;\u0026thinsp;5 years age group had a 1.9 times higher risk of cardiac death compared to the 0\u0026ndash;1 year age group, although not statistically significant (p\u0026thinsp;=\u0026thinsp;0.343) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Notably, five patients presenting with pre-excited AF were in the \u0026gt;\u0026thinsp;5 years age group. Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e summarizes and compares findings among neonates, infants, and others.\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\u003eComparing the survival time for LTE by age groups and examining the effect of age\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\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 \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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLTE number\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAverage survival time (%95 CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHR (%95 CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u0026ndash;1 year*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e0,339\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16,212 (14,861\u0026thinsp;\u0026minus;\u0026thinsp;17,563)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e1,881 (0,509\u0026ndash;6,943)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e0,343\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026gt;\u0026thinsp;5 years\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e14,515 (12,18\u0026thinsp;\u0026minus;\u0026thinsp;16,85)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOverall\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15,721 (14,533\u0026thinsp;\u0026minus;\u0026thinsp;16,909)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCharacteristics of the patients with WPW according to the age groups.\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\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNeonates\u003c/p\u003e \u003cp\u003en: 34\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInfants (\u0026lt;\u0026thinsp;1 year old)\u003c/p\u003e \u003cp\u003en: 14\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eChildren (\u0026gt;\u0026thinsp;1 year old)\u003c/p\u003e \u003cp\u003en: 112\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eFirst presentation LTE, n\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAsymptomatic patients, n\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePre-excited AF, n\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003enone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDecreased LV function, n\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSpontaneous resolution, n\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eAF: Atrial Fibrillation, LTE: Life threatening event, N: Number, WPW: Wolff Parkinson White Syndrome.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eComplete clinical recovery occurred in all cases of cardiac failure except for one subject who experienced acute kidney failure post-LTE, necessitating kidney transplantation in their teenage years. No deaths attributable to WPW or related arrhythmias were recorded in this cohort. However, one patient with pre-excitation and documented arrhythmia from neonatal to teenage years died following heart transplantation due to severe myocardial failure secondary to Danon disease.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study represents the largest epidemiological investigation of children with WPW syndrome in the UK, offering valuable insights into prevalence and LTE. Our findings reveal a WPW prevalence of 0.028% among children in South Wales, aligning closely with similar studies globally [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Notably, 8.1% of children presented with LTE, indicating a considerable risk of 3.8 events per 1000 patient-years, consistent with prior research [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUndoubtedly, the true incidence of WPW among children may be underestimated, considering asymptomatic cases and undocumented sudden cardiac deaths. However, these omissions are unlikely to significantly alter prevalence estimates. We observed a higher LTE risk in males (ratio 5 to 1), consistent with existing literature, despite comparable pre-excitation occurrence in both sexes [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHistorically, asymptomatic WPW was considered benign, but emerging evidence challenges this notion. Our study corroborates previous findings, suggesting LTE risk in asymptomatic patients with SCD as the initial presentation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In this regard, Sarubbi et all [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] reported that 30% of initially asymptomatic individuals develop symptoms over a-12 year follow-up period, A recent meta-analysis reported the overall risk of SCD for asymptomatic WPW patients at 0.85 events per 1000 person-years. It should be emphasized here that out-of-hospital mortality was not represented in this analysis.\u003c/p\u003e \u003cp\u003eWhile strenuous activities are commonly associated with an elevated LTE risk, it's noteworthy that sports restrictions alone would not have averted all LTE occurrences. A recent study revealed that 73% of LTEs did not occur during any competitive activity [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], aligning with our findings where the majority of LTEs (85%) occurred without competitive engagement. These observations echo previous reports highlighting that children with pre-excitation are susceptible to LTEs even during periods of rest or minimal activity [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOur cohort also revealed instances where atrial flutter in neonates with WPW led to cardiovascular collapse, emphasizing the severity of such events. Consequently, we advocate for including atrial flutter in the definition of life-threatening events (LTE) among children with WPW.\u003c/p\u003e \u003cp\u003eA striking case in our study involved a 5-year-old boy with asymptomatic preexcitation who suffered an episode of aborted SCD due to rapid conduction of AF during follow-up, necessitating cardiopulmonary resuscitation (CPR) with cardioversion. Remarkably, this child was also known to have epileptic seizures, raising the possibility that these seizures could have been triggered by unrecognized arrhythmic events. This case underscores the critical importance of meticulously evaluating electrocardiograms (ECGs) in children with unexplained or atypical epileptic seizures.\u003c/p\u003e \u003cp\u003eIt is also well known that ventricular pre-excitation can have detrimental effects on systolic function over time due to abnormal depolarization and repolarization of the myocardium. Accessory pathways can disrupt the typical sequence of ventricular activation, potentially leading to ventricular dyssynchrony, with higher impact for the right free wall and posterior septum locations [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Studies have demonstrated that ablation of these accessory pathways can restore normal ventricular function during follow-up [\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Consistent with these findings, our study observed that impaired left ventricular systolic function in all 18 patients (11.2%) returned to normal ranges following ablation.\u003c/p\u003e \u003cp\u003eEven if spontaneous resolution of WPW is a possibility, it is only observed in the minority of patients above the first year of life. [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Moreover, it remains crucial to follow up with these patients, as pre-excitation can re-emerge in 30% around the age of 8 years. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] In our study, pre-excitation re-emerged 12 years after diagnosis in one case. In another case, there was no evidence of a delta wave on 12-lead ECG, Holter, and exercise tests throughout childhood, but preexcitation manifested at 25 years of age with SVT.\u003c/p\u003e \u003cp\u003eThe utilization of electrophysiology studies to assess the risk associated with accessory pathways has traditionally centered on parameters like accessory pathway effective refractory period (APERP), shortest pre-excited R-R Interval during atrial pacing (SPERRI-Ap), and shortest pre-excited R-R interval during atrial fibrillation (SPERRI-AF) [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. However, it's increasingly evident that there are no definitive cutoffs in these non-invasive/invasive risk markers that guarantee 100% sensitivity. Consequently, patients with accessory pathways deemed low-risk based on benign conduction properties measured during electrophysiology studies may still experience life-threatening events (LTEs) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. A recent large multicenter study underscored this concern, revealing that 37% of children with LTEs in the series lacked high-risk accessory pathway characteristics during electrophysiology studies [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMoreover, when risk stratification was conducted, a study found that clinical SPERRI and SPERRI at EPS exhibited only moderate correlation under anesthesia, with 76.1% of asymptomatic and 55% of symptomatic patients showing this discrepancy [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Etheridge et al. demonstrated that a quarter of patients with a clinically high-risk SPERRI would have been erroneously classified as low-risk [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Our findings align with this conclusion, as we observed no significant differences in mean APERP, SPERRI, and SPPCL values between patients with multiple accessory pathways and those with asymptomatic pre-excitation. The occurrence rate of potentially hazardous pathways with short APERP was comparable between symptomatic and asymptomatic patients.\u003c/p\u003e \u003cp\u003eThe majority of patients in our cohort underwent radiofrequency (RF) ablation, with an overall success rate of the initial procedure at a commendable 84.4%, underscoring WPW as a condition largely amenable to cure. Left-sided accessory pathways predominated among patients experiencing LTEs. Notably, four patients necessitated a repeat ablation procedure for successful eradication of the accessory pathways.\u003c/p\u003e \u003cp\u003eAn important consideration in the ablation treatment of asymptomatic WPW cases is the risk of procedural complications, particularly in paediatric patients. However, a recent study investigating the safety of paediatric ablation in the UK revealed negligible occurrence rates of major complications such as heart block or neurological injury [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThis study underscores a heightened risk of life-threatening events in asymptomatic children with WPW syndrome in South Wales. Consequently, the findings of this national study emphasize the need for vigilant monitoring of children with WPW, irrespective of age or symptoms. Moreover, our study suggests a more proactive approach to referring younger children for radiofrequency ablation procedures before adolescence. Future national epidemiological studies should focus on establishing safer investigative methods, more reliable risk stratification techniques, and robust follow-up protocols. Given the unreliability of non-invasive risk stratification in WPW patients, electrophysiology study emerges as the primary mechanism for identifying high-risk individuals for life-threatening events during childhood.\u003c/p\u003e "},{"header":"Study limitations","content":"\u003cp\u003eWhile this study benefits from a robust central database for children in South Wales, its retrospective nature inherently poses limitations. One notable constraint is the inability to capture clinically silent and undiagnosed cases of WPW syndrome, potentially resulting in underrepresentation of the true prevalence. Additionally, the incidence of sudden death or cardiac arrest may have been underestimated due to the unavailability of electrocardiography in such cases. However, we believe the number of unrecognized WPW cases was minimal.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003e \u003cb\u003eTable\u0026nbsp;1\u003c/b\u003e \u003c/h2\u003e \u003cp\u003eBaseline EPS Data and Ablation Outcomes\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003e \u003cb\u003eTable\u0026nbsp;3\u003c/b\u003e \u003c/h2\u003e \u003cp\u003eComparing the survival time for LTE by age groups and examining the effect of age\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eOU, as an electrophysiologist, had primary responsibility for confirming the diagnosis of arrhythmia, collecting and facilitating data collection and analysis, writing the manuscript, and critically appraising it. GT, DD, YND, and AABH were clinical/visiting fellows who equally participated in data collection, analysis, statistical evaluation, and drafting the manuscript. MW, AGS, CGC, POC, FL, and OU were the electrophysiologists involved in EPS and ablation procedures at different times, as well as in writing and critically appraising the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWolff L, Parkinson J, White PD (2006) Bundle-branch block with short P-R interval in healthy young people prone to paroxysmal tachycardia. 1930. Ann Noninvasive Electrocardiol 11(4):340\u0026ndash;353\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEtheridge SP et al (2018) Life-Threatening Event Risk in Children With Wolff-Parkinson-White Syndrome: A Multicenter International Study. JACC Clin Electrophysiol 4(4):433\u0026ndash;444\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJanson CM et al (2022) Incidence of life-threatening events in children with Wolff-Parkinson-White syndrome: Analysis of a large claims database. Heart Rhythm 19(4):642\u0026ndash;647\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePappone C et al (2003) Usefulness of invasive electrophysiologic testing to stratify the risk of arrhythmic events in asymptomatic patients with Wolff-Parkinson-White pattern: results from a large prospective long-term follow-up study. J Am Coll Cardiol 41(2):239\u0026ndash;244\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eObeyesekere MN et al (2012) Risk of arrhythmia and sudden death in patients with asymptomatic preexcitation: a meta-analysis. Circulation 125(19):2308\u0026ndash;2315\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCain N et al (2013) Natural history of Wolff-Parkinson-White syndrome diagnosed in childhood. Am J Cardiol 112(7):961\u0026ndash;965\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMunger TM et al (1993) A population study of the natural history of Wolff-Parkinson-White syndrome in Olmsted County, Minnesota, 1953\u0026ndash;1989. Circulation 87(3):866\u0026ndash;873\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSarubbi B et al (2003) Asymptomatic ventricular pre-excitation in children and adolescents: a 15 year follow up study. Heart 89(2):215\u0026ndash;217\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBagnall RD et al (2016) A Prospective Study of Sudden Cardiac Death among Children and Young Adults. N Engl J Med 374(25):2441\u0026ndash;2452\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMellor G et al (2014) Clinical characteristics and circumstances of death in the sudden arrhythmic death syndrome. Circ Arrhythm Electrophysiol 7(6):1078\u0026ndash;1083\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFinocchiaro G et al (2017) Sudden Cardiac Death in Pre-Excitation and Wolff-Parkinson-White: Demographic and Clinical Features. J Am Coll Cardiol 69(12):1644\u0026ndash;1645\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohan S, Balaji S (2019) Management of asymptomatic ventricular preexcitation. Indian Pacing Electrophysiol J 19(6):232\u0026ndash;239\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwon BS et al (2010) Septal dyskinesia and global left ventricular dysfunction in pediatric Wolff-Parkinson-White syndrome with septal accessory pathway. J Cardiovasc Electrophysiol 21(3):290\u0026ndash;295\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTomaske M et al (2008) Adverse effects of Wolff-Parkinson-White syndrome with right septal or posteroseptal accessory pathways on cardiac function. Europace 10(2):181\u0026ndash;189\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eten Udink FE et al (2010) Dilated cardiomyopathy in children with ventricular preexcitation: the location of the accessory pathway is predictive of this association. J Electrocardiol 43(2):146\u0026ndash;154\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerry JC, Garson A Jr. (1990) Supraventricular tachycardia due to Wolff-Parkinson-White syndrome in children: early disappearance and late recurrence. J Am Coll Cardiol 16(5):1215\u0026ndash;1220\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEtheridge SP et al (2023) Asymptomatic Wolff-Parkinson-White Syndrome: An Ounce of Prevention Is Worth the Risk of Cure. Curr Cardiol Rep 25(6):543\u0026ndash;551\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeoni L et al (2023) Diagnosis and treatment of fetal and pediatric age patients (0\u0026ndash;12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways. J Cardiovasc Med (Hagerstown) 24(9):589\u0026ndash;601\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSantinelli V et al (2009) The natural history of asymptomatic ventricular pre-excitation a long-term prospective follow-up study of 184 asymptomatic children. J Am Coll Cardiol 53(3):275\u0026ndash;280\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrugada J et al (2013) Pharmacological and non-pharmacological therapy for arrhythmias in the pediatric population: EHRA and AEPC-Arrhythmia Working Group joint consensus statement. Europace 15(9):1337\u0026ndash;1382\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoca S, Akdeniz C, Tuzcu V (2019) Electrophysiological properties of asymptomatic children and adolescents with the Wolff-Parkinson-White electrocardiographic pattern]. Turk Kardiyol Dern Ars 47(8):674\u0026ndash;679\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChubb H et al (2019) Management of Asymptomatic Wolff-Parkinson-White Pattern by Pediatric Electrophysiologists. J Pediatr 213:88\u0026ndash;95e1\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalsh MA et al (2021) Outcomes From Pediatric Ablation: A Review of 20 Years of National Data. JACC Clin Electrophysiol 7(11):1358\u0026ndash;1365\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":"Wolff-Parkinson-White syndrome, children, atrial fibrillation, sudden death","lastPublishedDoi":"10.21203/rs.3.rs-4803843/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4803843/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackgrounds and Aims :\u003c/h2\u003e \u003cp\u003eThis study aims to assess the epidemiology, clinical presentation, management, and outcomes of pediatric Wolff-Parkinson-White (WPW) syndrome, as well as the incidence of life-threatening events (LTE) in South Wales.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eretrospective review of patients (\u0026lt;\u0026thinsp;17 years old) diagnosed with WPW syndrome between 1986 and 2019 in South Wales.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe study population consisted of 160 patients, of whom 86 (54%) were male. The prevalence of WPW syndrome was 0.028%. Thirty percent of cases were diagnosed during infancy, while 63% presented after aged 5. Incidental diagnosis occurred in 47 (29,3%) asymptomatic patients. Spontaneous resolution of delta wave was observed in 19 patients (11.9%). Thirteen children (8.1%, 11 males) presented with an LTE, resulting in an estimated LTE risk of 3.8 per 1000 person-years during childhood in South Wales. Acute management was required in 36% (55/154) of patients, with seven experiencing preexcited atrial fibrillation (4.5%). Among children with preexcited atrial fibrillation and rapid ventricular conduction, only three out of seven children experienced aborted sudden cardiac death (1.9%). No deaths directly attributable to isolated WPW and related arrhythmia were recorded.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eAsymptomatic WPW in children demonstrated a high propensity for life-threatening events in South Wales, prompting a policy shift towards earlier referral for electrophysiology study (EPS) prior to adolescence. These findings underscores the need for more rigorous risk stratification and closer follow-up of all WPW patients, as asymptomatic cases do not guarantee safety.\u003c/p\u003e","manuscriptTitle":"Epidemiology, clinical characteristics and life-threatening risk profile of WPW in children: 30 years population follow up at a single centre in South Wales","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-28 02:08:44","doi":"10.21203/rs.3.rs-4803843/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":"70043cb5-f4a8-4e4e-ade2-ce4db0372f4c","owner":[],"postedDate":"August 28th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-09-09T18:57:42+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-28 02:08:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4803843","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4803843","identity":"rs-4803843","version":["v1"]},"buildId":"ApUGefWb6u5IBVtyqm6d5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}