Although infrequently, asymptomatic patients with a Wolff. Original Article

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1 Original Article Electrophysiologic Profile and Results of Invasive Risk Stratification in Asymptomatic Children and Adolescents With the Wolff Parkinson White Electrocardiographic Pattern Peter Kubuš, MD; Pavel Vít, MD; Roman A. Gebauer, MD; Ondřej Materna, MD; Jan Janoušek, MD, PhD Background Data on the results and clinical effect of an invasive risk stratification strategy in asymptomatic young patients with the Wolff Parkinson White electrocardiographic pattern are scarce. Methods and Results Eighty-five consecutive patients aged <18 years with a Wolff Parkinson White pattern and persistent preexcitation at maximum exercise undergoing invasive risk stratification were retrospectively studied. Adverse accessory pathway (AP) properties were defined according to currently consented criteria as any of the following: shortest preexcited RR interval during atrial fibrillation/rapid atrial pacing 250 ms (or antegrade effective refractory period 250 ms if shortest preexcited RR interval was not available) or inducible atrioventricular re-entrant tachycardia. Age at evaluation was median 14.9 years. Eighty-two patients had a structurally normal heart and 3 had hypertrophic cardiomyopathy. A single manifest AP was present in 80, 1 manifest and 1 concealed AP in 4, and 2 manifest APs in 1 patient. Adverse AP properties were present in 32 of 85 patients (37.6%) at baseline and in additional 16 of 44 (36.4%) after isoproterenol. Ablation was performed in 41 of these 48 patients. Ablation was deferred in the remaining 7 for pathway proximity to the atrioventricular node. In addition, 18 of the low-risk patients were ablated based on patient/parental decision. Conclusions Adverse AP properties at baseline were exhibited by 37.6% of the evaluated patients with an asymptomatic Wolff Parkinson White preexcitation persisting at peak exercise. Isoproterenol challenge yielded additional 36.4% of those tested at higher risk. Ablation was performed in a total of 69.4% of patients subjected to invasive risk stratification. (Circ Arrhythm Electrophysiol. 2014;7: ) Key Words: child risk assessment Wolff Parkinson White syndrome Although infrequently, asymptomatic patients with a Wolff Parkinson White (WPW) electrocardiographic pattern experience sudden cardiac death because of life-threatening arrhythmias (typically atrial fibrillation with rapid antegrade conduction through an atrioventricular [AV] accessory pathway [AP], resulting in ventricular fibrillation). 1 3 The risk of such an event has been reported to be 0.1% per patient-year. 4 Attempts have been made to identify patients at high risk but specific guidelines for risk stratification in the asymptomatic young patients with WPW, including recommendation for the invasive electrophysiological (EP) evaluation and prophylactic catheter ablation of the AP, have not been published until recently. 5 The aim of the present study was to evaluate retrospectively the electrophysiological profile of asymptomatic children and adolescents with a WPW electrocardiographic pattern and to assess the results of an invasive risk stratification strategy applying currently consented risk criteria. 5 Editorial see p 187 Clinical Perspective on p 223 Methods Patients The study population was identified retrospectively from the clinical databases of 2 tertiary care centers providing invasive pediatric EP evaluation and radiofrequency (RF) catheter ablation for the whole territory of the Czech Republic (10.5 million inhabitants). Between October 2000 and August 2011, 85 consecutive patients (51 boys, 34 girls) under the age of 18 years with an asymptomatic WPW pattern underwent an invasive EP study for risk stratification. The patients had no antiarrhythmic medication and showed persistent preexcitation up to the maximum achieved heart rate during exercise stress testing before the EP study. The median age at EP evaluation was 14.9 (first third quartile [Q1 Q3]= ) years. Owing to the purely retrospective study design, the use of available institutional clinical records, absence of effect on Received July 26, 2013; accepted January 10, From the Children s Heart Center, University Hospital, Motol, Prague (P.K., O.M., J.J.); Pediatric Cardiology, Children s University Hospital Brno, Brno, Czech Republic (P.V.); Department of Pediatric Cardiology, University of Leipzig, Heart Center, Leipzig, Germany (R.A.G.). Correspondence to Peter Kubuš, MD, Dětské kardiocentrum, Fakultní nemocnice v Motole, V Úvalu 84, , Prague, Czech Republic. peter. kubus@lfmotol.cuni.cz 2014 American Heart Association, Inc. Circ Arrhythm Electrophysiol is available at DOI: /CIRCEP

2 Kubuš et al Risk Stratification in Children With WPW Pattern 219 patient management and completely anonymous data presentation, informed consent of the subjects (or their parents), and ethical approval have not been obtained. EP Procedures Retrospective analysis of EP records was performed. The EP procedures were routinely performed under conscious sedation or general anesthesia in selected patients. All patients have been evaluated for risk parameters of the AP at baseline. Adverse AP properties were defined according to a recent Consensus Statement document (Figure 1) 5 as the presence of shortest preexcited RR interval (SPERRI) during atrial fibrillation/rapid atrial pacing 250 ms or inducible AV re-entrant tachycardia. If SPERRI measurement was not available (21 of 85 patients), antegrade effective refractory period of the AP (AP ERP) 250 ms was used as a substitute. Furthermore, in the absence of risk parameters at baseline, isoproterenol (repetitive doses of 0.1 μg/kg IV or continuous infusion) was given to achieve an increase in the baseline heart rate of 50% to overcome the effect of anesthesia/conscious sedation on autonomic tone and to reproduce the effects of adrenergic stimulation. 6,7 Isoproterenol challenge was not performed in 9 patients without adverse AP properties at baseline. These patients were excluded when comparing the antegrade AP conduction parameters at baseline and after isoproterenol. Follow-Up Follow-up was routinely performed at 1 month and 1 year after the procedure. Median follow-up time was 13.5 (Q1 Q3= ) months after the invasive EP study. Statistical Analysis In the presence of non-gaussian distribution, continuous data were displayed as median and first third quartile. Mann Whitney ranksum test was used for comparison of continuous variables between 2 groups and Kruskall Wallis 1-way ANOVA on ranks for comparison of 3 groups. The Wilcoxon signed-rank test was used to assess the effect of isoproterenol challenge on AP properties in individual patients. Differences in proportions between 3 groups were tested by the χ 2 test followed by the Fisher exact test for pair-wise comparisons. All statistical analysis was performed using the SigmaPlot for Windows version 11.0 (Systat Software Inc, San Jose, CA) and SAS version 9.2 (SAS Institute Inc, Cary, NC). Results Patients Structurally normal heart was present in 82 of 85 and hypertrophic cardiomyopathy in 3 of 85 patients. A single manifest AP was found in 80 patients, 2 manifest APs in 1 patient, and the combination of 1 manifest AP and 1 concealed AP in 4 patients. Additional diagnoses were AV nodal re-entrant tachycardia in Figure 1. Management algorithm for the asymptomatic young patient with a WPW electrocardiographic pattern. Reproduced with permission from Cohen et al. 5 Authorization for this adaptation has been obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation (2012, Elsevier Limited).

3 220 Circ Arrhythm Electrophysiol April patients (slow pathway RF ablation was performed in 1) and focal atrial tachycardia in 1 patient (not ablated). The proportion of asymptomatic patients (ie, those involved in the study) in a group of all patients with WPW (including those with symptoms) undergoing an invasive EP evaluation was increasing during the study period (Figure 2). APs Properties Adverse AP properties were present in 32 of 85 patients (37.6%) at baseline (Table 1). Among those patients with both AP ERP and SPERRI measurements (n=63), AP ERP and SPERRI assigned 7.9% and 22.2% of the patients to the risk group, respectively (P=0.007). AP ERP 250 ms along with SPERRI >250 ms was seen in 1 patient only. Thus SPERRI was significantly more sensitive for detecting adverse AP conduction properties than AP ERP. In 1 patient, measurement of AP properties could not be performed because of the lack of both antegrade and retrograde conduction through the AP during the EP study. A group of 44 of 53 patients without adverse AP properties at baseline was subsequently subjected to isoproterenol challenge shifting 16 of these 44 patients tested (36.4%) into the higher risk category if using the cut off of 250 ms and 9 of 44 (20.5%) patients at the cut off of 220 ms (Table 1). Isoproterenol significantly increased the antegrade conduction capacity of the pathway (Table 2). From the total of 86 manifest APs, 10 of 86 (11.6%) were located at the right free wall, 51 of 86 (59.3%) were septal, and the remaining 25 of 86 (29.1%) were left-sided (P<0.001). There were no significant differences in antegrade conduction parameters and in the proportion of APs with adverse conduction parameters between the 3 localizations (Table 3). Intermittent preexcitation was present in 7 of 85 patients during the preprocedural Holter monitoring. Antegrade AP conduction properties were not different from the remaining patients (Table 4). AV re-entrant tachycardia was inducible in 2 of these 7 patients. RF Ablation RF ablation was performed in 41 of 48 patients (85.4%) assigned to the high-risk group (29 of 32 patients at baseline Number of patients Asymptomatic Symptomatic (I-VIII) Year of examination Figure 2. Number of patients with Wolff Parkinson White undergoing invasive electrophysiological testing during the study period. Table 1. Accessory Pathway Properties at Baseline and During Isoproterenol Challenge Risk Parameter Baseline (n=85) Isoproterenol (n=44*) Rapid antegrade 18 (21.2%) 15 (34.1%) 6 (13.6%) conduction Inducible AVRT 22 (25.9%) 4 (9.1%) 4 (9.1%) Total 32 (37.6%) 16 (36.4%) 9 (20.5%) AP indicates accessory pathway; AVRT, atrioventricular re-entrant tachycardia; ERP, effective refractory period; and SPERRI, shortest preexcited RR interval. *Without adverse AP properties at baseline. SPERRI during atrial fibrillation/rapid atrial pacing 250 ms or AP ERP 250 ms in the absence of SPERRI measurement. SPERRI during atrial fibrillation/rapid atrial pacing 220 ms or AP ERP 220 ms in the absence of SPERRI measurement. and 12 of 16 patients during isoproterenol challenge). In addition, 18 of 37 (48.6%) of the remaining patients carrying either low risk or not subjected to isoproterenol were ablated based on patient/parental decision. In total, ablation was performed in 59 of 85 patients (69.4%) and was deferred in 7 of 48 patients with adverse AP properties because of the AP proximity to the AV node. From these 7 patients, 6 remained asymptomatic over a mean follow-up of 13 months and the remaining 1 underwent catheter ablation of the AP in a repeated procedure later. Acute/long-term ablation success was 92.3 and 85.7%, respectively. There were no complications related to the EP study or RF ablation. There were no significant differences between both large centers participating in the study in any of the parameters evaluated. Discussion As shown in several studies, sudden cardiac death may be the first manifestation of the disease in patients with asymptomatic WPW preexcitation. 1,2,4 Infants and small children are probably at lower risk. 7 In a group of 184 asymptomatic children with a median age of 10 (range, 8 12) years, short AP ERP and multiple APs were independent predictors of life-threatening arrhythmic event. 8 Although noninvasive diagnostic methods such as 24-hour Holter monitoring and exercise stress testing are useful for basic assessment of the preexcitation, invasive testing should be considered to define electrophysiological properties of the AP in case of antegrade AP conduction persistence through maximum exercise. 5,9 12 Persistent preexcitation during exercise has high Table 2. Influence of Isoproterenol on Antegrade Accessory Pathway Conduction Capacity AP Properties (n=44) Baseline, ms Isoproterenol, ms P Value AP ERP median 320 ( ) 270 ( ) <0.001 (Q1 Q3) SPERRI median (Q1 Q3) 315 ( ) 244 ( ) <0.001 AP indicates accessory pathway; ERP, effective refractory period; Q1 Q3, first third quartile; and SPERRI, shortest preexcited RR interval during atrial fibrillation/rapid atrial pacing.

4 Kubuš et al Risk Stratification in Children With WPW Pattern 221 Table 3. Baseline Accessory Pathway Properties According to Localization AP Properties Right Free Wall (n=10) Septal (n=51) Left Free Wall (n=25) P Overall AP ERP median (Q1 Q3), ms 300 ( ) 300 ( ) 290 ( ) SPERRI median (Q1 Q3), ms 290 ( ) 300 ( ) 300 ( ) Rapid antegrade conduction* 0/10 10/51 8/ AP indicates accessory pathway; ERP, effective refractory period; NS, nonsignificant; Q1 Q3, first third quartile; and SPERRI, shortest preexcited RR interval during atrial fibrillation/rapid atrial pacing. *AP ERP 250 ms or SPERRI during atrial fibrillation/rapid atrial pacing 250 ms. P NS for all pair-wise comparisons by the Fisher exact test. sensitivity and high negative predictive value for detection of patients at risk. 13 However, patients with clear and abrupt loss of preexcitation during exercise testing are at low risk of sudden cardiac death. 10 Recently published recommendations qualify ablation of an asymptomatic pathway as a class IIA or IIB indication according to the presence of defined risk parameters. 5 In the present study, 69.4% of patients subjected to risk stratification underwent pathway ablation as a result of either the evaluated pathway properties or patient/parental decision. At baseline (without isoproterenol challenge), 21.2% of patients fulfilled the class IIA indication for catheter ablation 5 based on high antegrade AP conduction capacity, and additional 16.4% of patients had a IIB indication because of tachycardia inducibility. 5 The risk stratification approach is thus likely to change the natural course of asymptomatic WPW preexcitation with all potential positives and negatives. Pappone et al 14 could show a significant risk reduction of arrhythmic events in a randomized study of prophylactic ablation in asymptomatic patients 35 years of age with the WPW electrocardiographic pattern. However, catheter ablation is associated with a low but definite risk of complications. 15 This all has to be kept in mind when counseling the families. Patients with intermittent preexcitation on ECG/24- hour Holter monitoring are thought to be at lower risk for life-threatening arrhythmias. 16,17 Intermittent preexcitation is presumed to be a predictor of decreased antegrade AP conduction capacity 18 ; however, antegrade AP conduction may be present up to maximum exercise. Rare cases of patients with intermittent preexcitation and cardiac arrest have been reported. 19 Moreover, patients with intermittent preexcitation are still at risk for AV re-entrant tachycardia with retrograde activation of the atria via AP. 20 In our group, Table 4. Baseline Accessory Pathway Properties in Patients With Persistent and Intermittent Preexcitation During Preprocedural Holter Monitoring AP Properties Persistent Preexcitation (n=78) Intermittent Preexcitation (n=7) P Value AP ERP median 300 ( ) 300 ( ) (Q1 Q3), ms SPERRI median (Q1 Q3), ms 300 ( ) 310 ( ) AP indicates accessory pathway; ERP, effective refractory period; Q1 Q3, first third quartile; and SPERRI, shortest preexcited RR interval during atrial fibrillation/rapid atrial pacing. AV re-entrant tachycardia was inducible in 2 of 7 patients with intermittent preexcitation. None of these 7 patients exhibited rapid antegrade AP conduction. The difference in manifest AP antegrade conduction properties between patients with persistent and intermittent preexcitation was, however, not statistically significant. For these reasons, we consider reasonable to perform exercise stress testing in patients with intermittent preexcitation as an indicator for further electrophysiological study in case the patient/family favors the class IIB indication for catheter ablation as part of the treatment strategy. Szabo et al 21 showed that isoproterenol administration significantly shortened the SPERRI and increased the proportion of the asymptomatic adult patients with SPERRI 250 ms from 33% to 67%. Moore et al 22 demonstrated shortening of AP ERP and SPERRI after isoproterenol administration in children, with no significant difference between symptomatic and asymptomatic individuals. However, follow-up data for risk evaluation is lacking, and the role of isoproterenol challenge has not yet been clearly defined. 23 In several previous reports, SPERRI 220 ms on isoproterenol was suggested to define high-risk patients. 24 Because of the absence of consented criteria to define a potentially dangerous AP on isoproterenol, we used SPERRI or AP ERP cut off of both 250 ms and 220 ms to show the potential of isoproterenol to increase the yield of invasive testing. In general, isoproterenol lead to an increase of the number of individuals exhibiting adverse AP parameters regardless of the cut off used, presumably at the expense of a lower specificity. Because conscious sedation/general anesthesia is used in children, the use of isoproterenol may evoke a real-life situation of adrenergic stimulation and should be, in our opinion, a routine to better characterize the range of antegrade conduction capacity of the AP. In our study isoproterenol challenge converted 36.4% of patients without adverse AP properties at baseline into the higher risk group, a finding in accordance with the data by Szabo et al. 21 In this study, the difference in manifest AP antegrade conduction properties between the right free wall, septal, and left free wall APs was not significant. Compared with pediatric reports on the prevalence of specific pathway locations in children undergoing an invasive electrophysiological study, 25,26 there was a surprisingly high proportion of septal APs (59.3%) among our patients referred to risk stratification. Rapid AV nodal conduction during adrenergic stimulation may mask persistent preexcitation through a left-sided AP, 27 leading to a generally lower proportion of asymptomatic WPW patients with left-sided manifest APs referred to

5 222 Circ Arrhythm Electrophysiol April 2014 the EP study on the basis of exercise stress testing. Whether right-sided APs generally have a lower antegrade conduction capacity as a reason for underrepresentation in our cohort is not known. Study Limitations Retrospective character of the study and some variation in patient management during the procedure (conscious sedation versus general anesthesia, reflecting patient age at evaluation and center preference) were the main limitations of the study. In contrast to the recently published consensus statement, 5 AP ERP 250 ms was used to define rapid antegrade AP conduction in case of the absence of SPERRI measurement. Given the fact that SPERRI was significantly more sensitive in detecting high AP conduction capacity than AP ERP, some patients fulfilling the risk criteria might thus have been missed. The technique of isoproterenol administration varied between the 2 centers providing invasive EP studies (intravenous bolus versus continuous infusion). Isoproterenol challenge was not performed in 9 patients without adverse AP properties at baseline (all these patients were ablated based on patient/parental decision). Conclusions Applying retrospectively a currently consented risk stratification strategy, % of the evaluated asymptomatic patients with the WPW electrocardiographic pattern persisting at peak exercise exhibited adverse AP properties at baseline, fulfilling either the class IIA or IIB ablation indication. Isoproterenol challenge shifted additional 36.4% of those tested into 1 of these 2 indication classes. Safe ablation (remote from the AV node) could be performed in 85.4% of patients stratified to higher risk either at baseline or after isoproterenol. In addition, elective AP ablation was performed in 1 of 2 of the low-risk patients based on patient/parental decision, yielding a total of 69.4% of patients ablated as a result of the invasive risk stratification strategy. Sources of Funding This work was supported by Ministry of Health, Czech Republic and conceptual development of research organization, University Hospital Motol, Prague, Czech Republic None. Disclosures References 1. Montoya PT, Brugada P, Smeets J, Talajic M, Della Bella P, Lezaun R, vd Dool A, Wellens HJ, Bayés de Luna A, Oter R. Ventricular fibrillation in the Wolff-Parkinson-White syndrome. Eur Heart J. 1991;12: Klein GJ, Bashore TM, Sellers TD, Pritchett EL, Smith WM, Gallagher JJ. Ventricular fibrillation in the Wolff-Parkinson-White syndrome. N Engl J Med. 1979;301: Paul T, Guccione P, Garson A Jr. Relation of syncope in young patients with Wolff-Parkinson-White syndrome to rapid ventricular response during atrial fibrillation. Am J Cardiol. 1990;65: Klein GJ, Prystowsky EN, Yee R, Sharma AD, Laupacis A. Asymptomatic Wolff-Parkinson-White. Should we intervene? Circulation. 1989;80: Cohen MI, Triedman JK, Cannon BC, Davis AM, Drago F, Janoušek J, Klein GJ, Law IH, Morady FJ, Paul T, Perry JC, Sanatani S, Tanel RE. PACES/HRS Expert consensus statement on the management of the asymptomatic young patient with a Wolff-Parkinson-White (WPW, ventricular preexcitation) electrocardiographic pattern. Heart Rhythm. 2012;9: Moore JP, Kannankeril PJ, Fish FA. Isoproterenol administration during general anesthesia for the evaluation of children with ventricular preexcitation. Circ Arrhythm Electrophysiol. 2011;4: Wellens HJ, Brugada P, Roy D, Weiss J, Bär FW. Effect of isoproterenol on the anterograde refractory period of the accessory pathway in patients with the Wolff-Parkinson-White syndrome. Am J Cardiol. 1982;50: Santinelli V, Radinovic A, Manguso F, Vicedomini G, Gulletta S, Paglino G, Mazzone P, Ciconte G, Sacchi S, Sala S, Pappone C. The natural history of asymptomatic ventricular pre-excitation a long-term prospective follow-up study of 184 asymptomatic children. J Am Coll Cardiol. 2009;53: Czosek RJ, Anderson JB, Marino BS, Mellion K, Knilans TK. Noninvasive risk stratification techniques in pediatric patients with ventricular preexcitation. Pacing Clin Electrophysiol. 2011;34: Daubert C, Ollitrault J, Descaves C, Mabo P, Ritter P, Gouffault J. Failure of the exercise test to predict the anterograde refractory period of the accessory pathway in Wolff Parkinson White syndrome. Pacing Clin Electrophysiol. 1988;11: Bershader RS BC, Cecchin F. Exercise testing for risk assessment in pediatric Wolff-Parkinson-White syndrome. Heart Rhythm. 2007;4: Dubin AM, Collins KK, Chiesa N, Hanisch D, Van Hare GF. Use of electrophysiologic testing to assess risk in children with Wolff-Parkinson-White syndrome. Cardiol Young. 2002;12: Gaita F, Giustetto C, Riccardi R, Mangiardi L, Brusca A. Stress and pharmacologic tests as methods to identify patients with Wolff-Parkinson-White syndrome at risk of sudden death. Am J Cardiol. 1989;64: Pappone C, Santinelli V, Manguso F, Augello G, Santinelli O, Vicedomini G, Gulletta S, Mazzone P, Tortoriello V, Pappone A, Dicandia C, Rosanio S. A randomized study of prophylactic catheter ablation in asymptomatic patients with the Wolff-Parkinson-White syndrome. N Engl J Med. 2003;349: Kugler JD, Danford DA, Houston KA, Felix G; Pediatric Radiofrequency Ablation Registry of the Pediatric Radiofrequency Ablation Registry of the Pediatric Electrophysiology Society. Pediatric radiofrequency catheter ablation registry success, fluoroscopy time, and complication rate for supraventricular tachycardia: comparison of early and recent eras. J Cardiovasc Electrophysiol. 2002;13: Milstein S, Sharma AD, Klein GJ. Electrophysiologic profile of asymptomatic Wolff-Parkinson-White pattern. Am J Cardiol. 1986;57: Klein GJ, Gulamhusein SS. Intermittent preexcitation in the Wolff-Parkinson-White syndrome. Am J Cardiol. 1983;52: Kinoshita S, Konishi G, Kinoshita Y. Mechanism of intermittent preexcitation in the Wolff-Parkinson-White syndrome. The concept of electronically mediated conduction across an inexcitable gap. Chest. 1990;98: Pietersen AH, Andersen ED, Sandøe E. Atrial fibrillation in the Wolff-Parkinson-White syndrome. Am J Cardiol. 1992;70:38A 43A. 20. Fitzsimmons PJ, McWhirter PD, Peterson DW, Kruyer WB. The natural history of Wolff-Parkinson-White syndrome in 228 military aviators: a long-term follow-up of 22 years. Am Heart J. 2001;142: Szabo TS, Klein GJ, Sharma AD, Yee R, Milstein S. Usefulness of isoproterenol during atrial fibrillation in evaluation of asymptomatic Wolff-Parkinson-White pattern. Am J Cardiol. 1989;63: Moore JP, Kannankeril PJ, Fish FA. Isoproterenol administration during general anesthesia for the evaluation of children with ventricular preexcitation. Circ Arrhythm Electrophysiol. 2011;4: Pass RH, Ceresnak SR. Wolff-Parkinson-White syndrome and isoproterenol testing in children: a valid adjunct to predict risk? Circ Arrhythm Electrophysiol. 2011;4: Sarubbi B, Scognamiglio G, Limongelli G, Mercurio B, Pacileo G, Pisacane C, Russo MG, Calabrò R. Asymptomatic ventricular pre-excitation in children and adolescents: a 15 year follow up study. Heart. 2003;89: Pruszkowska-Skrzep P, Pluta S, Lenarczyk A, Kowalski O, Lenarczyk R, Kurek T, Zdrzałek-Skiba A, Chodór B, Zeifert B, Szkutnik M,

6 Kubuš et al Risk Stratification in Children With WPW Pattern 223 Białkowski J, Kalarus Z. A comparison of the clinical course of preexcitation syndrome in children and adolescents and in adults. Cardiol J. 2007;14: Jung HJ, Ju HY, Hyun MC, Lee SB, Kim YH. Wolff-Parkinson-White syndrome in young people, from childhood to young adulthood: relationships between age and clinical and electrophysiological findings. Korean J Pediatr. 2011;54: Perry JC, Giuffre RM, Garson A Jr. Clues to the electrocardiographic diagnosis of subtle Wolff-Parkinson-White syndrome in children. J Pediatr. 1990;117: CLINICAL PERSPECTIVE The management of the asymptomatic young patient with a Wolff Parkinson White electrocardiographic pattern has considerably changed during the past 2 decades. Studies in both adults and children have pointed toward the not entirely benign nature of this condition because of the possibility of rapid antegrade conduction over the accessory pathway during atrial fibrillation. However, catheter ablation has become a highly effective and safe method of treatment for the Wolff Parkinson White syndrome. A risk stratification strategy has recently been recommended in a Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society document (Heart Rhythm. 2012;9: ) for asymptomatic patients. The current study extends our knowledge on the consequences of such risk stratification. Depending on whether isoproterenol challenge will be used or not, between 1 of 3 and 2 of 3 of children exhibiting persistent preexcitation at peak exercise will fulfill either a class IIA or IIB ablation indication during electrophysiological testing. Taken together with the increasing number of asymptomatic young individuals subjected to 12-lead ECG as a part of various screening strategies, invasive risk stratification is likely to alter the natural history of the asymptomatic Wolff Parkinson White electrocardiographic pattern in a significant proportion of patients.