Clinical and electrophysiologic evolution of the Wolff-Parkinson-White syndrome in children: impact on approaches to management

Impact of growth on electrophysiological properties of ventricular pre-excitation in paediatric athletes

AIM

Risk stratification is recommended for patients with ventricular pre-excitation, particularly when sports eligibility is required. Few studies have examined the changes in the electrophysiological properties of the accessory pathway during growth. This study investigates the evolution of electrophysiological properties of the ventricular pre-excitation in young athletes referred for sports eligibility.

METHODS

Between January 2011 and July 2022, 44 paediatric patients (32 males; mean age, 10 ± 2.42) with ventricular pre-excitation underwent an electrophysiological study, both at rest and during adrenergic stress at two different times (T0 and T1) within a minimal interval of 2 years. Transcatheter ablation was not performed between the two electrophysiological studies. Electrophysiological data were collected and compared.

RESULTS

Electrophysiological study under basal conditions showed a significant decrease in the anterograde accessory pathway effective refractory period and 1:1 conduction over the accessory pathway from T0 to T1. The shortest pre-excited R-R interval during atrial fibrillation did not significantly change at the basal condition; however, it decreased during the stress test. Furthermore, six patients (13.6%) changed the risk profile of their accessory pathway: two "high-risk" patients at T0 became "low-risk" and four "low-risk" patients became "high-risk" at T1. Atrioventricular re-entry tachycardia inducibility did not differ significantly between the two electrophysiological studies.

CONCLUSIONS

This study highlights the importance of repeating electrophysiological study (transesophageal or intracardiac) in paediatric athletes with ventricular pre-excitation because significant and clinically relevant changes in the conduction and refractoriness of accessory pathway can occur. This could influence risk stratification for sports eligibility and the correct indication and timing for accessory pathway ablation.

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

Supraventricular tachycardias in the first year of life: what is the best pharmacological treatment? 24 years of experience in a single centre

Background

Supraventricular tachycardias (SVTs) are common in the first year of life and may be life-threatening. Acute cardioversion is usually effective, with both pharmacological and non-pharmacological procedures. However, as yet no international consensus exists concerning the best drug required for a stable conversion to sinus rhythm (maintenance treatment). Our study intends to describe the experience of a single centre with maintenance drug treatment of both re-entry and automatic SVTs in the first year of life.

Methods

From March 1995 to April 2019, 55 patients under one year of age with SVT were observed in our Centre. The SVTs were divided into two groups: 45 re-entry and 10 automatic tachycardias. As regards maintenance therapy, in re-entry tachycardias, we chose to start with oral flecainide and in case of relapses switched to combined treatment with beta-blockers or digoxin. In automatic tachycardias we first administered a beta-blocker, later combined with flecainide or amiodarone when ineffective.

Results

The patients’ median follow-up time was 35 months. In re-entry tachycardias, flecainide was effective as monotherapy in 23/45 patients (51.1%) and in 20/45 patients (44.4%) in combination with nadolol, sotalol or digoxin (overall 95.5%). In automatic tachycardias, a beta-blocker alone was effective in 3/10 patients (30.0%), however, the best results were obtained when combined with flecainide: overall 9/10 (90%).

Conclusions

In this retrospective study on pharmacological treatment of SVTs under 1 year of age the combination of flecainide and beta-blockers was highly effective in long-term maintenance of sinus rhythm in both re-entry and automatic tachycardias.

Does the age of evaluation change the long-term follow-up of untreated pre-excitation syndrome?

BACKGROUND

Due to high rates of ablation at the time of diagnostic EP study, follow-up of the natural history of untreated pre-excitation syndrome has become difficult. We present patients in which such data is available and study the effect of initial age on the evolution.

METHODS

In this retrospective review, 126 patients, 47 aged ≤19 years, 79 aged more than>19 underwent 2 similar electrophysiological studies (EPS) within 1 to 25 years of one another (8.8 ± 6.8) for occurrence of symptoms or new evaluation. First EPS was indicated for syncope (10), atrioventricular re-entrant tachycardias (AVRT) (58), atrial fibrillation (AF) (5), spontaneous PS-related adverse event (7) or asymptomatic PS (46).

RESULTS

Clinical data remained unchanged in 76 patients (60.3%). AVRT symptom was more frequently unchanged than other symptoms. Electrophysiological data remained unchanged in 105 patients (82%), but signs of initial malignant signs were variable with a disappearance in 53.5% of patients. At EPS1, AF induction was rarer in patients ≤19 years. Syncope had a low predictive value of malignant form. AVRT induction at EPS1 was not predictive of AVRT occurrence. Maximal rate over accessory pathway increased, but unexpected changes could occur. After multivariate analysis, data of first EPS were limited for the prediction of AVRT or adverse event; effect of age was not significant.

CONCLUSIONS

Clinical data remained unchanged in 60.3% of patients and electrophysiological data in 82%. Initial age of evaluation did not change the modifications. Electrophysiological signs associated with sudden death varied over time. Clinical AVRT was inconstantly related to inducible AVRT (78.5%).

Evolution of Clinical and Electrophysiological Data in Children with a Preexcitation Syndrome

BACKGROUND

With ablation, the follow-up of preexcitation syndrome now is difficult to assess. The purpose was to collect data of children with a preexcitation syndrome studied on two separate occasions within a minimal interval of 1 year.

METHODS

This is a retrospective chart review of 47 children initially aged 12 ± 4 years, who underwent two or more invasive electrophysiological studies (EPS) within 1-25 years of one another (6.3 ± 4.8) for occurrence of symptoms or new evaluation.

RESULTS

Among initially symptomatic children (n = 25), four (19%) became asymptomatic and one presented life-threatening arrhythmia. Among asymptomatic children (n = 22), five became symptomatic (22.7%). Anterograde conduction disappeared in seven of 23 children with initially long accessory pathway-effective refractory period, but four of six had still induced atrioventricular reentrant tachycardia (AVRT). AVRT was induced at second EPS in three of 13 asymptomatic preexcitation syndrome with negative initial EPS. There were no spontaneous adverse events in the five children with criteria of malignancy at initial EPS; signs of malignancy disappeared in two. At multivariate analysis, AVRT at initial EPS was the only independent factor of symptomatic AVRT during follow-up. Absence of induced AVRT at initial EPS was the only factor of absence of symptoms and a negative study at the second EPS.

CONCLUSIONS

There were no significant changes of data in children after 6.3 ± 4.8 years of follow-up. Most children with spontaneous/inducible AVRTs at initial EPS had still inducible AVRT at second EPS. Induced AF conducted with high rate has a relatively low prognostic value for the prediction of adverse events.

Electrophysiology testing and catheter ablation are helpful when evaluating asymptomatic patients with Wolff-Parkinson-White pattern: the con perspective

The association between asymptomatic Wolff-Parkinson-White (WPW) syndrome and sudden cardiac death (SCD) has been well documented. The inherent properties of the accessory pathway determine the risk of SCD in WPW, and catheter ablation essentially eliminates this risk. An approach to WPW syndrome is needed that incorporates the patient's individualized considerations into the decision making. Patients must understand that there is a trade-off of a small immediate risk of an invasive approach for elimination of a small lifetime risk of the natural history of asymptomatic WPW. Clinicians can minimize the invasive risk by only performing ablation for patients with at-risk pathways.

Impact of transesophageal electrophysiologic study to elucidate the mechanism of arrhythmia on children with supraventricular tachycardia and no preexcitation

An electrophysiologic study (EPS) of children and teenagers with paroxysmal supraventricular tachycardia (SVT) and normal electrocardiography (ECG) in sinus rhythm was evaluated. Generally, EPS is performed only before paroxysmal SVT ablation in these patients. In this study, 140 patients (mean age, 15 ± 3 years) with normal ECG in sinus rhythm were studied for SVT by a transesophageal route in baseline state and after isoproterenol. Idiopathic left or right ventricular tachycardia was diagnosed in four patients (3 %). Anterograde conduction over an atrioventricular (AV) left lateral (n = 10) or septal (n = 9) accessory pathway (AP) was noted in 19 patients (13.5 %) at atrial pacing. Orthodromic AV reentrant tachycardia (AVRT) was induced in these children. Five of the patients had a high rate conducted over AP (>240 bpm in baseline state or >290 bpm after isoproterenol). Two of the patients (a 10-year-old girl with well-tolerated SVT and a 17-year-old with syncope-related SVT) had the criteria for a malignant form with the induction of atrial fibrillation conducted over AP at a rate exceeding 290 bpm in baseline state. Of the 140 patients, 74 (53 %) had typical AV node reentrant tachycardia (AVNRT), nine had atypical AVNRT (6 %), 1 had atrial tachycardia (0.7 %), and 33 (23.5 %) had AVRT related to a concealed AP with only retrograde conduction. Electrophysiologic study is recommended for children with paroxysmal SVT and normal ECG in sinus rhythm. The data are helpful for guiding the treatment. Ventricular tachycardia or atrial tachycardia can be misdiagnosed. Masked preexcitation syndrome with anterograde conduction through AP was present in 13.5 % of the patients, and 1.4 % had a malignant preexcitation syndrome.

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.

Risk of Arrhythmia and Sudden Death in Patients With Asymptomatic Preexcitation

Background—

The incidence of sudden cardiac death (SCD) and the management of this risk in patients with asymptomatic preexcitation remain controversial. The purpose of this meta-analysis was to define the incidence of SCD and supraventricular tachycardia in patients with asymptomatic Wolff-Parkinson-White ECG pattern.

Methods and Results—

We performed a systematic search of prospective, retrospective, randomized, or cohort English-language studies in EMBASE and Medline through February 2011. Studies reporting asymptomatic patients with preexcitation who did not undergo ablation were included. Twenty studies involving 1869 patients met our inclusion criteria. Participants were primarily male with a mean age ranging from 7 to 43 years. Ten SCDs were reported involving 11 722 person-years of follow-up. Seven studies originated from Italy and reported 9 SCDs. The risk of SCD is estimated at 1.25 per 1000 person-years (95% confidence interval [CI], 0.57–2.19). A total of 156 supraventricular tachycardias were reported involving 9884 person-years from 18 studies. The risk of supraventricular tachycardia was 16 (95% CI, 10–24) events per 1000 person-years of follow-up. Children had numerically higher SCD (1.93 [95% CI, 0.57–4.1] versus 0.86 [95% CI, 0.28–1.75]; P =0.07) and supraventricular tachycardia (20 [95% CI, 12–31] versus 14 [95% CI, 6–25]; P =0.38) event rates compared with adults.

Conclusion—

The low incidence of SCD and low risk of supraventricular tachycardia argue against routine invasive management in most asymptomatic patients with the Wolff-Parkinson-White ECG pattern.

Safety and efficacy of flecainide in the treatment of symptomatic children with Wolff-Parkinson-White syndrome

Sudden cardiac death may occur in children with symptomatic and asymptomatic Wolff-Parkinson-White syndrome (WPWS). Symptomatic patients are usually treated with antiarrhythmic drugs until ablation of an accessory pathway (AP) could be performed. The objective of this study was to review the safety and efficacy of flecainide in the treatment of children with symptomatic WPWS. Twenty-two children (14 male) with WPWS and without structural heart disease were studied. AP location was achieved by electrophysiological testing or 12-lead electrocardiogram tracing. Symptomatic children (i.e., those frequent palpitations or supraventricular tachycardia episodes) received flecainide. Patients were followed-up for an average of 3.4 years until ablation of AP. Eighteen children reported clinical symptoms when first diagnosed, but only 13 initiated treatment during 16.23 months (range 1-55). Flecainide was effective in all patients: Seven became asymptomatic, and six experimented isolated episodes of palpitations. One child experienced hair loss as a side effect. AP location was as follows: left free wall (n = 7), right free wall (n = 4), posteroseptal (n = 8), and anteroseptal (n = 4). Ablation was performed without complications in 13 children. Symptomatic WPWS in children can be treated safely and efficiently with flecainide. It represents a good alternative therapy until AP ablation can be performed.

Chaotic atrial tachycardia-related ventricular fibrillation in a 2-month-old baby with Wolff-Parkinson-White syndrome

A 2-month-old baby was resuscitated from ventricular fibrillation attributed to a concurrent chaotic atrial tachycardia with Wolff-Parkinson-White syndrome. He underwent successful radiofrequency catheter ablation of an accessory pathway. Throughout the 4-year follow-up after the procedure, the boy remained free of any drugs, was in sinus rhythm without ventricular pre-excitation and his growth and development were normal.

[Transesophageal electrophysiological study in non sedated children younger than 11 years with a Wolff-Parkinson-White syndrome]

The electrophysiological evaluation of Wolff-Parkinson-White syndrome (WPW) is recommended in children aged more than five years to detect a risk of life-threatening arrhythmia. The purposes of the study were to determine the feasibility of transesophageal EPS in a child between six and 10 years in out-patient clinic.

METHODS

Electrophysiological study (EPS) was indicated in 22 children, aged six to 10 years, with a manifest WPW either for no documented tachycardia (n=7), unexplained dizziness (n=2) or for a sportive authorization in 10 asymptomatic children. Two of the last children had a history of permanent tachycardia after the birth but were asymptomatic since the age of one year without drugs.

RESULTS

EPS was performed in all children. The main difficulty lied in passing the catheter through the mouth. Programmed stimulation at cycle length of 380 ms was performed in all children to avoid high rates of pacing when the conduction through the accessory pathway (AP) and normal AV system was evaluated. Isoproterenol was not required in five children, because they developed a catecholaminergic sinus tachycardia. The AP refractory period was determined in all children between 200 and 270 ms. Orthodromic reentrant tachycardia (RT) was induced in 11 children, three asymptomatic children (27%), seven complaining of tachycardia and one with syncope. Rapid antidromic tachycardia was induced in this last child with dizziness. Atrial fibrillation was never induced.

CONCLUSIONS

Esophageal EPS can be performed without sedation in a young child six to 10-year-old with a shortened protocol of stimulation, which was capable to clearly evaluate the WPW-related risks.

Clinical and electrophysiological characteristics, and relatively benign outcome, of typical atrioventricular nodal reentrant tachycardia in children and adolescents

BACKGROUND

Atrioventricular nodal re-entrant tachycardia is an uncommon arrhythmia in children. The natural history of this disturbance is poorly known in young patients.

METHODS

We analyzed the clinical and electrophysiological features, and the final outcome, in 19 children affected by typical atrioventricular nodal re-entrant tachycardia diagnosed by a transoesophageal electrophysiological study.

RESULTS

Of the cohort, 12 patients were female and 7 male, with a mean age of 11 years. Dual atrioventricular nodal physiology was demonstrated in 14 children (73%). The mean length of the tachycardia cycle was 297 milliseconds, with periods of 2 to 1 atrioventricular block during tachycardia noted in 5 children (26%). The mean cycle length was significantly shorter in the children who presented episodes of 2 to 1 atrioventricular block than in those who did not. After diagnosis, 12 children were not treated, 6 were treated with medical therapy, and 1 was submitted to radiofrequency transcatheter ablation. During a mean follow-up period of 41 months, 2 children with rare, but sustained, episodes of tachycardia that initially had not been treated were submitted to radiofrequency transcatheter ablation. Among children treated pharmacologically, 1 teenager was submitted to radiofrequency transcatheter ablation on the basis of parental choice, 3 children have discontinued medical therapy recording only sporadic episodes of tachycardia, and 2 children are still treated with antiarrhythmic drugs. At the last follow-up visit, 13 children (68%) were without any treatment, 4 had been successfully ablated, and 2 were still on medical treatment.

CONCLUSIONS

Our data indicates a relatively benign outcome in this group of children and adolescents with atrioventricular nodal re-entrant tachycardia.

When should we recommend catheter ablation for patients with the Wolff-Parkinson-White syndrome?

PURPOSE OF REVIEW

Catheter ablation has been proven as very effective and safe therapy for patients with symptomatic Wolff-Parkinson-White (WPW) syndrome. Its application in asymptomatic individuals with WPW pattern remains controversial. This review will elaborate on the role of catheter ablation in symptomatic and asymptomatic patients with WPW pattern on ECG.

RECENT FINDINGS

Several recent prospective studies evaluated invasive risk stratification followed by prophylactic catheter ablation in asymptomatic patients with WPW pattern. Inducibility of arrhythmias in these patients during invasive electrophysiological study was shown to predict the development of future symptomatic arrhythmias. Although ablation of accessory pathways performed in 'inducible' patients decreased the incidence of subsequent symptomatic arrhythmias, the studies were not powered to detect a reduction in life-threatening arrhythmias.

SUMMARY

Radiofrequency catheter ablation remains the first-line therapy for patients with symptomatic WPW syndrome. Invasive electrophysiological study and possible ablation of accessory pathway may be offered to well informed asymptomatic individuals with WPW if they are willing to trade the very small risk of subsequent sudden death or incapacity for a small immediate procedural risk of serious complications or death. Asymptomatic patients may require invasive risk stratification and possible catheter ablation for important social or professional reasons.

Pediatric arrhythmias: which are the news?

Knowledge about cardiac arrhythmias has significantly improved in the last 20 years, and the improvements in diagnosis and in therapy have also had important effects on the management of pediatric arrhythmias. In this paper, the most important developments in the field of management of pediatric arrhythmias (fetal arrhythmias, genetics, pharmacological strategies, radiofrequency ablation, new technologies) as well as the remaining problems (risk stratification of some arrhythmic forms as for example Wolff-Parkinson-White and ventricular arrhythmias) will be discussed.

Wolff-Parkinson-White Syndrome: Essentials for the Primary Care Nurse Practitioner

PURPOSE

To provide nurse practitioners with a basic understanding of the pathophysiology, clinical characteristics, diagnostic methods, and management of Wolff-Parkinson-White (WPW) syndrome.

DATA SOURCES

Selected research and clinical articles.

CONCLUSIONS

WPW syndrome is the most common form of ventricular preexcitation. The ventricular myocardium is activated earlier than expected by an accessory conduction pathway that allows a direct electrical connection between the atria and ventricles. Although many patients remain asymptomatic throughout their lives, approximately half of the patients with WPW syndrome experience symptoms secondary to tachyarrhythmias, such as paroxysmal supraventricular tachycardia, atrial fibrillation, atrial flutter, and, rarely, ventricular fibrillation and sudden death. Symptoms include palpitations, dizziness, syncope, and dyspnea. Diagnosis is usually made by electrocardiogram findings, but further testing may be warranted to confirm the diagnosis.

IMPLICATIONS FOR PRACTICE

A thorough patient history and physical examination can aid the practitioner in identifying patients who may have WPW syndrome. With appropriate referral, treatment, and patient education, patients with WPW syndrome can expect to have a normal life expectancy and good quality of life.

Prevalence of arrhythmias and conduction disturbances in large population-based samples of children

The aim of our study is to provide data on the prevalence of disturbances of rhythm in the general population of children. Accurate estimates of true prevalence of such disturbances of rhythm from large samples are mandatory if we are to interpret properly electrocardiographic abnormalities. We analysed prevalence of disturbances of rhythm in a population of 152,322, comprised of 71,855 elementary school students, 36,692 males and 35,163 females, aged from 5 to 6 years, and 80,467 students of junior high school, 41,842 males and 38,625 females, aged from 12 to 13 years. We analysed the prevalence of premature atrial and ventricular contractions, first, second and third degree atrioventricular block, incomplete and complete right bundle branch block, Wolff-Parkinson-White syndrome, and prolongation of the QT interval. The prevalence of disturbances of rhythm in total rose with age, being found in 1.25% of elementary school students and 2.32% of junior high school students, and was higher in males than females, at 2.00% as opposed to 1.38%, both values being statistically significant at a level of less than 0.0001. Prevalences of all types of rhythmic disturbances were higher in junior high school students than elementary school students (p < 0.0001). Premature atrial and ventricular contractions and prolongation of the QT interval were higher in female than male students, at percentages of 0.089, 0.497, and 0.02 for males, and 0.123, 0.534 and 0.027 in females (p < 0.0001). In contrast, incomplete and complete right bundle branch blocks were higher in males than females, at 0.983% and 0.083% in males versus 0.410% and 0.161% in females (p < 0.0001). Disturbances of rhythm increased with age, and conduction disturbances were higher in male students than female, although premature atrial and ventricular contractions and prolongation of the QT interval were more frequent in female. These data may be useful for future comparative studies of disturbance of rhythm in children.

The Different Electrophysiological Characteristics in Children with Wolff-Parkinson-White Syndrome Between Those with and Without Atrial Fibrillation

Atrioventricular reciprocating tachycardia (AVRT) is known to be the most common supraventricular tachycardias in childhood. Because AF with rapid ventricular response may degenerate to ventricular fibrillation through conduction of accessory pathways (APs), it can be potentially life-threatening in some pediatric patients with WPW syndrome. However, information about WPW syndrome children associated with AF is limited. The purpose of this study was to investigate the specific electrophysiological characteristics in pediatric patients with WPW syndrome and AF. From July 1992 to February 2002, 51 pediatric patients with manifest WPW syndrome and documented AVRT underwent electrophysiological study and radiofrequency catheter ablation. In these patients, two (4%) were found to have several spontaneous episodes of AF recognized on 12-lead standard ECG or 24-hour Holter monitoring. Eleven (22%) patients had AF induced by rapid atrial pacing during the baseline procedure of electrophysiological study. The children with manifest WPW syndrome were divided into two groups: those with AF (group 1; n = 11) consisted of seven male and four female children (mean age 15 +/- 3 years, range 10-18), and those without AF (group 2; n = 40) consisted of 22 boys and 18 girls (mean age 16 +/- 3 years, range 7-18). The study excluded a patient who had Ebstein's anomaly associated with moderate tricuspid regurgitation and right atrial enlargement. The onset and duration of symptoms were not significantly different between the two groups. Comparing the electrophysiological characteristics, the atrial effective refractory period (ERP) was shorter in WPW syndrome children with AF (170 +/- 36 vs 190 +/- 38 ms, P = 0.041). This study demonstrated that the pediatric WPW syndrome patients with AF had different electrophysiological characteristics from those without AF.