Impact of clinical history and electrophysiologic characterization of accessory pathways on management strategies to reduce sudden death among children with Wolff-Parkinson-White syndrome

2024 HRS expert consensus statement on arrhythmias in the athlete: Evaluation, treatment, and return to play

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

Wolf-Parkinson-White Syndrome: Diagnosis, Risk Assessment, and Therapy-An Update

Wolf-Parkinson-White (WPW) syndrome is a disorder characterized by the presence of at least one accessory pathway (AP) that can predispose people to atrial/ventricular tachyarrhythmias and even sudden cardiac death. It is the second most common cause of paroxysmal supraventricular tachycardia in most parts of the world, affecting about 0.1-0.3% of the general population. Most patients with WPW syndrome have normal anatomy, but it may be associated with concomitant congenital heart disease or systemic diseases. Although many individuals are asymptomatic, during supraventricular arrhythmia episodes, they may experience severe symptoms, including syncope or even sudden cardiac death (mainly due to pre-excited atrial fibrillation over rapidly conducting AP). In addition to arrhythmia-related symptoms, for some specific locations of the APs with overt anterograde conduction, there might be a reduction in exercise capacity mediated by a reduction in LV systolic performance due to anomalous LV depolarization. Although it is typically diagnosed through electrocardiography (ECG), additional tests are necessary for risk assessment. Management of WPW syndrome may be quite challenging and can vary from only acknowledging the presence of the accessory pathway to pharmacological treatment or radiofrequency ablation. Early diagnosis, risk assessment, and appropriate treatment are critical steps in the management of WPW syndrome, aiming to improve the quality of life and reduce the risk of life-threatening arrhythmias.

Asymptomatic Wolff-Parkinson-White Syndrome: An Ounce of Prevention Is Worth the Risk of Cure

PURPOSE OF REVIEW

With increased electrocardiogram screening, asymptomatic preexcitation has become more prevalent. Historically, the asymptomatic-symptomatic dichotomy has directed management. This approach warrants scrutiny, as asymptomatic Wolff-Parkinson-White (WPW) syndrome is not without risk. Children may be unreliable symptom reporters, have atypical arrhythmia symptoms, yet have years to become symptomatic.

RECENT FINDINGS

In a large WPW study, symptomatic patients were more likely to undergo ablation than asymptomatic patients, yet, except for symptoms, there were no differences in clinical or electrophysiology study (EPS) characteristics. Present data confirm real risk in asymptomatic WPW-sudden death can be the first symptom. Although malignant arrhythmias correlate better with EPS risk stratification than with symptoms, EPS data are imperfect predictors. Unlike adults with WPW, children have yet to prove survivorship. Asymptomatic children must be treated differently than adults. Sudden death risk is low but front-loaded in the young. An aggressive approach to asymptomatic WPW is warranted in this era of highly successful, low-risk catheter ablations.

Recommendations for participation in leisure-time physical activity and competitive sports in patients with arrhythmias and potentially arrhythmogenic conditions: Part 1: Supraventricular arrhythmias. A position statement of the Section of Sports Cardiology and Exercise from the European Association of Preventive Cardiology (EAPC) and the European Heart Rhythm Association (EHRA), both associations of the European Society of Cardiology

Symptoms attributable to arrhythmias are frequently encountered in clinical practice. Cardiologists and sport physicians are required to identify high-risk individuals harbouring such conditions and provide appropriate advice regarding participation in regular exercise programmes and competitive sport. The three aspects that need to be considered are: (a) the risk of life-threatening arrhythmias by participating in sports; (b) control of symptoms due to arrhythmias that are not life-threatening but may hamper performance and/or reduce the quality of life; and (c) the impact of sports on the natural progression of the underlying arrhythmogenic condition. In many cases, there is no unequivocal answer to each aspect and therefore an open discussion with the athlete is necessary, in order to reach a balanced decision. In 2006 the Sports Cardiology and Exercise Section of the European Association of Preventive Cardiology published recommendations for participation in leisure-time physical activity and competitive sport in individuals with arrhythmias and potentially arrhythmogenic conditions. More than a decade on, these recommendations are partly obsolete given the evolving knowledge of the diagnosis, management and treatment of these conditions. The present document presents a combined effort by the Sports Cardiology and Exercise Section of the European Association of Preventive Cardiology and the European Heart Rhythm Association to offer a comprehensive overview of the most updated recommendations for practising cardiologists and sport physicians managing athletes with supraventricular arrhythmias, and provides pragmatic advice for safe participation in recreational physical activities, as well as competitive sport at amateur and professional level. A companion text on recommendations in athletes with ventricular arrhythmias, inherited arrhythmogenic conditions, pacemakers and implantable defibrillators is published as Part 2 in Europace.

Sudden Cardiac Death in Patients with Ventricular Preexcitation

Patients with the Wolff-Parkinson-White syndrome may experience benign and malignant arrhythmias, the most common being atrioventricular reentrant tachycardias. This arrhythmia may degenerate into atrial fibrillation, which can be conducted over an accessory pathway capable of exceptionally fast conduction to the ventricles and degenerate into ventricular fibrillation, leading to sudden cardiac death. These life-threatening events generally affect symptomatic patients in their third or fourth decade. Although rare, ventricular fibrillation may be the first clinical manifestation in subjects who are asymptomatic or unaware of their conditions. Electrophysiologic study may be useful to identify subjects at high risk of sudden cardiac death.

The use of intravenous amiodarone in patients with atrial fibrillation and Wolff-Parkinson-White syndrome

BACKGROUND

It was reported that intravenous amiodarone might induce ventricular fibrillation for acute treatment in patients with atrial fibrillation (AF) and Wolff-Parkinson-White (WPW) syndrome. No study was done to assess its application comprehensively in this population.

METHODS

This study was a retrospective analysis and undertaken by reviewing medical records and electronic databases to search for patients admitted with tachycardia resulting from WPW syndrome and AF, who have intravenously administrated amiodarone at the emergency department from January 2008 to June 2018.

RESULTS

Thirty patients were involved in this study, of which 27 were males. The mean age of the patients was 47.8 ± 17.0 years. The mean systolic blood pressure and diastolic blood pressure were 111.9 ± 18.3 mmHg and 76.1 ± 14.6 mmHg, respectively. The mean heart rate was 171 (150-189) beats per minute. Half of the patients (53.3%) had no comorbidities, and only one had prior syncope. Nearly 17 patients (56.7%) started with a loading dose of 150 mg. No ventricular acceleration or VF developed. The incidence of hypotension was 3.3% (1/30). Eighteen patients (60.0%) restored to sinus rhythm by amiodarone with the conversion time of 486.0 (229.0-1278.0) minutes.

CONCLUSIONS

Intravenous amiodarone might be an alternative for acute treatment of AF and WPW syndrome in patients characterized by stable hemodynamics, relatively low admission heart rate, few comorbidities, elder age, and no prior syncope. The loading dosage of 150 mg appeared to be preferred, and the maintenance period was better to less than 12 hours. Monitoring and electrolyte correction were also necessary. It is essential to keep a defibrillator nearby during pharmacologic cardioversion.

Difficulties with invasive risk stratification performed under anesthesia in pediatric Wolff-Parkinson-White Syndrome

BACKGROUND

Children with Wolff-Parkinson-White Syndrome (WPW) are at risk for sudden death. The gold standard for risk stratification in this population is the shortest pre-excited RR interval during atrial fibrillation (SPERRI).

OBJECTIVE

The purpose of this study was to determine how closely measurements made in the electrophysiology laboratory in patients with WPW compared to SPERRI obtained during an episode of clinical pre-excited atrial fibrillation (Clinical-SPERRI).

METHODS

This was a subgroup analysis of a multicenter study of children with WPW. Subjects in our study (N = 49) were included if they had Clinical-SPERRI measured in addition to 1 or more of 3 surrogate measurements: SPERRI obtained during electrophysiological study (EP-SPERRI), accessory pathway effective refractory period (APERP), or shortest pre-excited paced cycle length with 1:1 conduction (SPPCL).

RESULTS

Seventy percent of electrophysiological measurements were made with patients under general anesthesia. Clinical-SPERRI moderately correlated with EP-SPERRI (r = 0.495; P = .012). However, 24% of our patients with Clinical-SPERRI ≤250 ms would have been misclassified as having a low-risk pathway based on EP-SPERRI >250 ms. Clinical-SPERRI did not correlate with APERP or SPPCL (r < 0.3; P >.1). Mean EP-SPERRI, APERP, and SPPCL all were greater than Clinical-SPERRI.

CONCLUSION

Electrophysiology laboratory measurements of pathway characteristics made with patients under general anesthesia do not correlate well with Clinical-SPERRI. Of APERP, SPPCL, and EP-SPERRI, only EP-SPERRI had moderate correlation with Clinical-SPERRI. This study questions the predictive ability of invasive risk stratification with patients under general anesthesia, given that 24% of patients with high-risk Clinical-SPERRI (≤250 ms) had EP-SPERRI that may be considered low risk (>250 ms).

Utility and safety of adenosine challenge for subtle ventricular pre-excitation in the pediatric population

INTRODUCTION

Adenosine challenge (AC) can be used to evaluate possible Wolff-Parkinson-White (WPW) pattern on an electrocardiogram (ECG). Despite the use of this technique, there is a paucity of studies in the pediatric population evaluating the efficacy, safety, and outcomes of this testing modality.

METHODS AND RESULTS

All ACs performed from January 2009 to June 2017 were retrospectively reviewed. Patient demographics, adenosine dosing, results, adverse effects, and outcomes including results of electrophysiology studies (EPS) were reviewed. Analysis was conducted between AC positive and negative cohorts. ECG criteria of shortest PR interval, longest QRS duration, and the number of suspected pre-excited leads were evaluated for inter-rater reliability and correlation to positive AC. Fifty-six AC (n = 51) were performed (median age, 13.8; range, 0.3-20 years). Forty-one AC were pre-EPS and 15 post-EPS due to concern for recurrent WPW. Thirty-one (76%) pre-EPS AC were negative, 9 (22%) positive, and 1 (2%) equivocal. EPS was performed following seven positive AC revealing 5 (71%) left posterior and 2 (29%) right posteroseptal AP. The 15 post-EPS AC were all found to be negative. Mean effective adenosine dose was 0.2 ± 0.11 mg/kg. No adverse events were reported. Mean follow up duration after AC was 314 ± 482 days with no documented arrhythmias.

CONCLUSION

Adenosine challenge is an effective and safe testing modality for subtle WPW in the pediatric population. In our population, there were no adverse events or documented arrhythmias in patients following a negative study.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Atrioventricular accessory pathways in 89 dogs: Clinical features and outcome after radiofrequency catheter ablation

Background

Atrioventricular accessory pathways (APs) in dogs have been reported rarely. Data regarding clinical presentation and long‐term outcome after radiofrequency catheter ablation (RFCA) are limited.

Hypothesis/Objectives

To study clinical features, electrophysiologic characteristics, and outcome of RFCA in dogs with APs.

Animals

Eighty‐nine dogs presented consecutively for RFCA of APs.

Methods

Case series.

Results

Labrador retrievers (47.2% of dogs) and male dogs (67.4% of dogs) were most commonly affected. Labrador retrievers were more likely to be male than non‐Labrador breeds (P = .043). Clinical signs were nonspecific and most commonly included lethargy and gastrointestinal signs. Concealed APs were more prevalent in Labrador retrievers than other breeds (P = .001). Right‐sided APs (91.7%) predominated over left‐sided (8.3%). Tachycardia‐induced cardiomyopathy (TICM) occurred in 46.1% of dogs, with complete resolution or substantial improvement noted on one‐month postablation echocardiograms. Radiofrequency catheter ablation successfully eliminated AP conduction long term in 98.8% of dogs in which it was performed. Complications occurred in 5/89 dogs. Recurrence in 3 dogs was eliminated long term with a second procedure.

Clinical Importance/Conclusions

Accessory pathways are challenging to recognize in dogs because of nonspecific clinical signs, frequency of concealed APs that show no evidence of their presence during sinus rhythm, and intermittent occurrence of tachyarrhythmias resulting from APs. Tachycardia‐induced cardiomyopathy commonly occurs with AP‐mediated tachycardias and should be considered in any dog presenting with a dilated cardiomyopathic phenotype because of its good long‐term prognosis with rhythm control. Radiofrequency catheter ablation is a highly effective method for eliminating AP conduction and providing long‐term resolution.

Characteristic features of patients with multiple accessory pathways

Objective Only limited clinical and electrophysiological data concerning patients (pts) with multiple accessory pathways (MAP) in comparison to large control groups are available. The aim of our study was to analyse these data from the largest cohort of patients with multiple accessory pathways and a large control group. Method and results We analysed data from pts with MAP (group 1) and pts with a single accessory pathway (AP) (group 2) referred for radiofrequency catheter ablation (RFCA) at our tertiary centre. Group 1 consisted of 124 pts (M 62.10%, mean age 33.00 ± 5.26) with MAP and RFCA. Group 2 consisted of 376 pts (M 51.20%, mean age 35.87 ± 16.15) with a single accessory pathway and RF ablation. Group 1 exhibited a higher incidence of overt APs (P < 0.0001), Ebstein anomaly (P = 0.001), ventricular fibrillation (P = 0.012), antidromic atrioventricular re-entrant tachycardia (A AVRT) (P = 0.025) and male gender (P = 0.038). The mean age at the first documented atrioventricular re-entrant tachycardia (AVRT) episode was lower in pts with MAP than in pts with single APs: 16.79 ± 13.41 vs 20.84 ± 14.29, respectively (P = 0.001). Concealed accessory pathways (P < 0.0001) occurred more frequently in the control group. Group 1 had more right-lateral (P = 0.0001), mid-septal (P = 0.0001), left-posterior (P = 0.01), left-anterior (P = 0.013) and left-lateral localizations of AP (P < 0.037). Conclusions The MAP group included statistically significantly more men, Ebstein anomaly and overt APs. The mean age of the first episode of atrioventricular re-entrant tachycardia was lower in pts with MAP. Certain distribution patterns are apparent for single and MAP. Pts with MAP are at higher risk of VF and antidromic atrioventricular re-entrant tachycardia.

Wolff-Parkinson-White syndrome: lessons learnt and lessons remaining

The Wolff-Parkinson-White pattern refers to the electrocardiographic appearance in sinus rhythm, wherein an accessory atrioventricular pathway abbreviates the P-R interval and causes a slurring of the QRS upslope - the "delta wave". It may be asymptomatic or it may be associated with orthodromic reciprocating tachycardia; however, rarely, even in children, it is associated with sudden death due to ventricular fibrillation resulting from a rapid response by the accessory pathway to atrial fibrillation, which itself seems to result from orthodromic reciprocating tachycardia. Historically, patients at risk for sudden death were characterised by the presence of symptoms and a shortest pre- excited R-R interval during induced atrial fibrillation <250 ms. Owing to the relatively high prevalence of asymptomatic Wolff-Parkinson-White pattern and availability of catheter ablation, there has been a need to identify risk among asymptomatic patients. Recent guidelines recommend invasive evaluation for such patients where pre-excitation clearly does not disappear during exercise testing. This strategy has a high negative predictive value only. The accuracy of this approach is under continued investigation, especially in light of other considerations: Patients having intermittent pre-excitation, once thought to be at minimal risk may not be, and the role of isoproterenol in risk assessment.

The Historical Perspective of Athletic Sudden Death

Since antiquity, the athlete has been elevated to a heroic status both within small communities and at the international level. Although numerous population studies have estimated athletic sudden death to be a rare event, the consequences resonate far beyond those directly affected. Sports cardiology has evolved as a result of these tragedies, which highlighted a need for safer play and more programmatic protection of the athlete in play. In this article, athletic sudden death is analyzed from a historical and literary perspective and the development of modern initiatives to protect athletes from sudden death is reviewed.

The Wolf-Parkinson-White ECG Pattern - Assessing the Mortality Risk

The presence of a Wolf-Parkinson-White (WPW) pattern is not uncommonly discovered on a life insurance applicant's ECG. How does one determine the appropriate mortality risk in this population? This article will discuss the risk of sudden cardiac death (SCD), the interpretation of electrophysiology testing results, and risk-stratification both for asymptomatic individuals and those who have had ablation treatment.

Exercise testing in children with Wolff-Parkinson-White syndrome: what is its value?

This study was conducted to evaluate the accuracy of exercise testing for predicting accessory pathway characteristics in children with Wolff-Parkinson-White (WPW) syndrome. The study enrolled 37 children with WPW syndrome and candidates for invasive electrophysiologic study (EPS). Exercise testing was performed for all the study participants before the invasive study. Data from the invasive EPS were compared with findings from the exercise testing. The sudden disappearance of the delta (Δ) wave was seen in 10 cases (27 %). No significant correlation was found between the Δ wave disappearance and the antegrade effective refractory period of the accessory pathway (AERP-AP) or the shortest pre-excited RR interval (SPERRI). The sensitivity, specificity, and positive and negative predictive values of Δ wave disappearance, based on AERP-AP as gold standard, were respectively 29.4, 80, 71.4, and 40 %. The corresponding values with SPERRI as the gold standard were respectively 23.8, 71.4, 71.4 and 23.8 %. Exercise testing has a medium to low rate of accuracy in detecting low-risk WPW syndrome patients in the pediatric age group.

Clinical and electrophysiological evaluation of pediatric Wolff-Parkinson-White patients

Objective:

Wolff-Parkinson-White (WPW) syndrome presents with paroxysmal supraventricular tachycardia and is characterized by electrocardiographic (ECG) findings of a short PR interval and a delta wave. The objective of this study was to evaluate the electrophysiological properties of children with WPW syndrome and to develop an algorithm for the management of these patients with limited access to electrophysiological study.

Methods:

A retrospective review of all pediatric patients who underwent electrophysiological evaluation for WPW syndrome was performed.

Results:

One hundred nine patients underwent electrophysiological evaluation at a single tertiary center between 1997 and 2011. The median age of the patients was 11 years (0.1-18). Of the 109 patients, 82 presented with tachycardia (median age 11 (0.1-18) years), and 14 presented with syncope (median age 12 (6-16) years); 13 were asymptomatic (median age 10 (2-13) years). Induced AF degenerated to ventricular fibrillation (VF) in 2 patients. Of the 2 patients with VF, 1 was asymptomatic and the other had syncope; the accessory pathway effective refractory period was ≤180 ms in both. An intracardiac electrophysiological study was performed in 92 patients, and ablation was not attempted for risk of atrioventricular block in 8 (8.6%). The success and recurrence rate of ablation were 90.5% and 23.8% respectively.

Conclusion:

The induction of VF in 2 of 109 patients in our study suggests that the prognosis of WPW in children is not as benign as once thought. All patients with a WPW pattern on the ECG should be assessed electrophysiologically and risk-stratified. Ablation of patients with risk factors can prevent sudden death in this population.

Age-related prognosis of syncope associated with a preexcitation syndrome

BACKGROUND

Syncope in Wolff-Parkinson-White syndrome (WPW) is without relationship with WPW or reveals a poorly tolerated arrhythmia. Electrophysiologic study (EPS) is recommended. The purpose of the study was to evaluate the influence of the patient's age on the causes and prognosis of syncope.

METHODS

A total of 98 patients, mean age 35 ± 18 years, with WPW were admitted for syncope. Note that 29 were aged between 9 and 19 years (mean 15 ± 3) (children and teenagers/group I), 45 between 20 and 49 years (mean 34 ± 8) (adults/group II), and 24 between 50 and 70 years (mean 60 ± 8) (elderly/group III). EPS consisted of atrial pacing and programmed atrial stimulation in control state and after isoproterenol.

RESULTS

Potentially malignant form (rapid conduction in accessory pathway >240 beats/min in control state or >300 beats/min after isoproterenol and atrial fibrillation [AF] induction) was more frequent in group I (34%) than in groups II (7%) (P < 0.002) and III (0%) (P < 0.001). Orthodromic atrioventricular reentrant tachycardia (AVRT) and AF were induced as frequently in groups I (59, 34%), II (47, 15.5%), and III (54, 17%). AVRT was induced in all but one patient with malignant form. EPS was as frequently negative in groups I (27.5%), II (44%), and III (37.5%). Natural follow-up (mean 8 ± 6 years) indicated a favorable prognosis, only related to AVRT induction. Induced AF was without significance.

CONCLUSIONS

Data in syncope and WPW syndrome depended on age: electrophysiological malignant form was frequent in children/teenagers, rare in adults, and absent in elderly. AVRT, the main cause of syncope, was as frequent in all ranges of age. AF's induction alone had no significance. Final prognosis was favorable.

Multiple accessory pathways in the young: the impact of structural heart disease

BACKGROUND

The presence of multiple accessory pathways (MultAP) is described in structural heart disease (SHD) such as Ebstein's anomaly and cardiomyopathies. Structural defects can impact the tolerability of tachyarrhythmia and can complicate both medical management and ablation. In a large cohort of pediatric patients with and without SHD undergoing invasive electrophysiology study, we examined the prevalence of MultAP and the effect of both MultAP and SHD on ablation outcomes.

METHODS

Accessory pathway number and location, presence of SHD, ablation success, and recurrence were analyzed in consecutive patients from our center over a 16-year period.

RESULTS

In 1088 patients, 1228 pathways (36% retrograde only) were mapped to the right side (TV) in 18%, septum (S) in 39%, and left side (MV) in 43%. MultAP were present in 111 pts (10%), involving 250 distinct pathways. SHD tripled the risk of MultAP (26% SHD vs 8% no SHD, P < .001). Multivariable adjusted risk factors for MultAP included Ebstein's (OR 8.7[4.4-17.5], P < .001) and cardiomyopathy (OR 13.3[5.1-34.5], P < .001). Of 1306 ablation attempts, 94% were acutely successful with an 8% recurrence rate. Ablation success was affected by SHD (85% vs 95% for no SHD, P < .01) but not by MultAP (91% vs 94% for single, P = .24). Recurrence rate was higher for SHD (17% SHD vs 8% no SHD, P < .05) and MultAP (19% MultAP vs 8% single, P < .001).

CONCLUSIONS

MultAP are found in 10% of pediatric patients, and are more common in SHD compared to those with normal hearts. Both the presence of MultAP and SHD negatively influence ablation outcomes.

Asymptomatic Wolff-Parkinson-White Syndrome Should be Ablated

Wolff-Parkinson-White syndrome (WPW) is associated with a small but lifetime risk of cardiac arrest and/or sudden cardiac death (SCD). However, the exact risk is not well defined, particularly in asymptomatic persons. Over recent years the authors have collected and reported new follow-up data among a large number of asymptomatic WPW patients, particularly children, intensively followed. These data have significantly contributed to the knowledge and definition of the natural history of WPW from childhood to adulthood. The risk of SCD is higher in asymptomatic children than in adults, and early ablation can be offered only to selected subjects after electrophysiologic testing.

Atrial fibrillation induction by transesophageal electrophysiology studies in patients with asymptomatic ventricular preexcitation

OBJECTIVE

Ventricular preexcitation is a conduction abnormality caused by an accessory pathway bridging the atria and ventricles. If the accessory pathway conducts rapidly during atrial fibrillation (AFib), sudden death may result. The purpose of this study was to determine the ability of transesophageal electrophysiology studies (TEEPS) to induce AFib in pediatric patients with asymptomatic ventricular preexcitation (aVPE).

DESIGN

A retrospective review of patients with aVPE who had a TEEPS was conducted. Inclusion criteria were evidence of ventricular preexcitation on electrocardiogram; age <18 years; and no history of tachycardia, palpitations, or syncope. Data gathered included age, weight, height, form of sedation, and TEEPS results. If AFib was induced, patients were classified as at risk of sudden death if the shortest preexcited RR interval during AFib was <250 ms or no risk if ≥ 250 ms.

RESULTS

A total of 26 patients met the inclusion criteria, with average age of 11.9 years, weight of 48.9 kg, and height of 149.2 cm. During the procedure, nine patients underwent conscious sedation (34.6%), and 17 underwent general anesthesia (65.4%). AFib was induced in 23 patients (88.5%), of whom 17 (73.9%) had no risk and six (26.1%) had risk. No statistical differences were noted in age, weight, height, or form of sedation when comparisons were made between AFib induction and no AFib induction.

CONCLUSIONS

TEEPS induced AFib in 88.5% of patients. Age, weight, height, and form of sedation had no effect upon AFib inducibility. TEEPS is an effective modality to induce AFib in pediatric patients with aVPE.

Induction of atrial fibrillation with adenosine during a transesophageal electrophysiology study to risk stratify a patient with asymptomatic ventricular preexcitation

An asymptomatic adolescent male athlete was incidentally found to have ventricular preexcitation on electrocardiogram during a sports preparticipation physical. A transesophageal electrophysiology study (TEEPS) was performed after an exercise stress test failed to delineate the patient's risk of sudden cardiac death. The TEEPS was favored in this case over a transvenous electrophysiology study due to reduced invasiveness. The goal of the TEEPS was to place the patient into atrial fibrillation (AFib) and evaluate the shortest preexcited RR interval during AFib, thereby assessing the risk of his accessory pathway. Conventional pacing modalities were unable to induce AFib. During atrial burst pacing, adenosine was then administered, which successfully induced AFib. This case highlights adenosine's potential to induce atrial fibrillation during transesophageal electrophysiology studies when atrial pacing alone was unable to do so.

Ablation of supraventricular tachycardia allows more liberal therapy in some children with attention-deficit-hyperactivity disorder

BACKGROUND

First-line therapy for children with attention-deficit-hyperactivity disorder (ADHD) is stimulant medication, which may have potential cardiovascular side-effects. In patients with supraventricular tachycardia or Wolf-Parkinson-White syndrome (WPW), therapy for ADHD could become challenging. The purpose of the present study was to review the authors' experience of performing electrophysiologic study (EPS) with or without ablation to determine how it affected ADHD therapy.

METHODS

Retrospective chart review of patients who underwent EPS between 2002 and 2009 was carried out. All patients under 21 years of age who had prior diagnosis of ADHD were included.

RESULTS

Twenty patients met the inclusion criteria. The mean age was 12.1 ± 2.7 years (range: 5.6-16.8 years). The patients were diagnosed with ADHD on average 3.9 ± 2.7 years (range: 6 months-9 years) prior to the EPS. All patients had a structurally normal heart. Sixteen patients had cardiac symptoms. Seventeen patients underwent ablation of the arrhythmia substrate (16/17, 94% successful). Three patients with asymptomatic WPW were at low risk for life-threatening arrhythmias and did not have ablation. After the EPS, two patients had increased doses of their ADHD medications, and two patients whose health-care providers stopped the stimulant medication prior to EPS because of recurrent tachycardia were restarted on medications. All other patients on ADHD medications continued therapy.

CONCLUSIONS

EPS for risk stratification and ablation of arrhythmia substrate is safe and effective, allowing more liberal therapy in patients with ADHD and supraventricular tachycardia or WPW.