Noninvasive Risk Stratification Techniques in Pediatric Patients with Ventricular Preexcitation

["Asymptomatic WPW" : Is treatment necessary?]

The term "asymptomatic WPW" (Wolff-Parkinson-White) is often used as a synonym for ventricular pre-excitation of the WPW type due to an accessory pathway characterized by a short PR interval and a delta wave on the electrocardiogram (ECG) without the clinical occurrence of paroxysmal tachycardia. Asymptomatic WPW is often diagnosed in young and otherwise healthy people. There is a small associated risk of sudden cardiac death due to rapid antegrade conduction over the accessory pathway during atrial fibrillation. This paper highlights aspects of noninvasive and invasive risk stratification, therapy by catheter ablation, and the ongoing risk-benefit discussion in asymptomatic WPW.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes

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Evaluation of AP is usually performed by transesophageal and intracardiac studies.

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In young athletes with AVP, our standard of care is to perform ESnoXR.

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ESnoXR may considered a less invasive alternative for risk stratification of AP.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Review paper on WPW and athletes: Let sleeping dogs lie?

Accessory pathways are present in 1 in 300 young individuals. They are often asymptomatic and potentially lethal arrhythmias may be the first presentation. During long-term follow-up, up to 20% of asymptomatic individuals with pre-excitation go on to develop an arrhythmia and the absence of traditional clinical and electrophysiological high-risk markers does not guarantee the "safe" nature of an accessory pathway. The widespread availability of permanent cure for the condition at low risk by catheter ablation, creates an incentive to screen for accessory pathways with a 12-lead ECG, particularly in individuals who are perceived to be at increased risk, such as athletes and high-risk professions. We review the existing literature on the assessment and management of accessory pathways (Wolff-Parkinson-White [WPW] syndrome) and discuss its implications for the young athletic population.

Management of asymptomatic ventricular preexcitation

An incidental discovery of Wolff Parkinson White (WPW) pattern on the electrocardiogram (ECG) is not an infrequent finding facing the physician. Most patients discovered incidentally are asymptomatic and it is hard to justify further management of such patients given the time-honored adage to “first do no harm.” However, this finding does have implications. This article is an attempt to guide clinicians about this important issue that is often faced in the office.

Comparison of Electrophysiologic Profiles in Pediatric Patients with Incidentally Identified Pre-Excitation Compared with Wolff-Parkinson-White Syndrome

The rising utilization of screening electrocardiograms has resulted in increased incidental identification of ventricular pre-excitation in pediatric patients. We compared accessory pathways of incidentally identified pre-excitation to Wolff-Parkinson-White Syndrome (WPW) with the aim to identify factors important in preprocedural counseling and planning. This single-center, retrospective study of patients ≤18 years without congenital heart disease identified 227 patients diagnosed with pre-excitation and referred for invasive electrophysiology study between 2008 and 2017. WPW Syndrome was diagnosed in 178 patients, while 49 patients had incidental identification of pre-excitation. Anterograde conduction of incidentally identified accessory pathways was not clinically different between the two cohorts at baseline or upon isoproterenol infusion. However, the proportion of accessory pathways meeting high-risk criteria was significantly lower than in patients diagnosed with WPW, 12% versus 28% (p < 0.05). Retrograde conduction at baseline of incidentally diagnosed accessory pathways was slower with a median block cycle length 365 milliseconds (IQR 260 to 450) versus 290 milliseconds (IQR 260 to 330, p < 0.01). In the incidentally identified cohort, right-sided, paraHisian, and fascicular pathways were more common with fewer attempted ablations (71% vs 94%, p < 0.001) and lower success rate (91% vs 97%, p < 0.001). A binomial logistic regression analysis further indicated patients incidentally identified with pre-excitation were associated with having lower rates of inducible supraventricular tachycardia, atrial fibrillation, and ablations performed, in addition, to having right-sided pathways. In conclusion, as patients with incidentally identified pre-excitation present more frequently for consideration of invasive electrophysiology study, these results impact procedural approaches, technical considerations, patient counseling, and outcome expectations.

Can noninvasive testing identify benign patterns of suggested pre-excitation on electrocardiogram?

BACKGROUND

The presence of anterograde conduction through an accessory pathway (AP) has been linked to sudden cardiac death. Unfortunately, pre-excitation associated with classic pathways can be difficult to differentiate from benign APs such as nodofascicular fibers.

OBJECTIVE

Identifying characteristics on electrocardiogram (ECG) and exercise that differentiate classic and benign AP connections in suggested pre-excitation patterns.

METHODS

Retrospective review of patients presenting between 1995 and 2017 with ventricular pre-excitation on ECG, determined to have either typical left-lateral AP during electrophysiology study (EPS), or benign, or no AP determined by either transesophageal electrophysiology study (TEP), or EPS.

RESULTS

A total of 96 patients were included, 14.2 years (4-24), 45% female, 90% Caucasian. Of these, 60 (63%) had a classic APs identified on EPS and 58 (97%) underwent successful ablation. Conversely, 36 (37%) had benign pathways identified. ECG findings differed between the groups: PR-interval 102 versus 120 ms (P < .0001), QRS-duration 110 versus 102 ms (P < .0001), QRS-axis 74 versus 59 degrees (P = .0005), and QRS onset to peak R/S in limb leads 64 versus 42 ms (P < .0001), and precordial leads 66 versus 46 ms (P < .0001). Change in QRS duration during exercise differed between the groups: 25 versus 2 ms (P < .0001) and ECG characteristics identified the presence of an AP with 97% sensitivity and 94% negative predictive value.

CONCLUSION

Classic and benign APs exhibit different ECG characteristics, though clinical overlap does not allow for absolute differentiation. These data may help with risk stratification decision making though does not obviate the need for additional invasive testing.

Unresolved questions associated with the management of ventricular preexcitation syndrome

BACKGROUND

Many recent recommendations concern the management of preexcitation syndrome. In clinical practice, they are sometimes difficult to use. The purpose of the authors was to discuss the main problems associated with this management. Three problems are encountered: (1) the reality of the absence of symptoms or the interpretation of atypical symptoms, (2) the electrocardiographic diagnosis of preexcitation syndrome that can be missed, and (3) the exact electrophysiological protocol and its interpretation used for the evaluation of the prognosis. Because of significant progress largely related to the development of curative treatment, it seems easy to propose ablation in many patients despite the related risks of invasive studies and to minimize the invasive risk by only performing ablation for patients with at-risk pathways. However, there is a low risk of spontaneous events in truly asymptomatic patients and the indication of accessory pathway ablation should be discussed case by case.

Heart rate variability parameters in children with ventricular preexcitation

INTRODUCTION

The autonomic nervous system has a regulatory effect on cardiac electrophysiology and arrhythmogenesis. We aimed to assess cardiac autonomic status using heart rate variability (HRV) parameters in children with ventricular preexcitation.

METHODS

The electrocardiography, Holter monitoring, transesophageal electrophysiological study (TEEPS), and invasive electrophysiological study (EPS) results of ventricular preexcitation patients obtained over a 7-year period in our clinic were evaluated. According to the TEEPS results, patients' accessory pathway conduction was classified as adverse (n = 40) or nonadverse (n = 25). The HRV parameters of patients were compared according to tachycardia inducibility that assessed by TEEPS and EPS. Also, HRV parameters were compared in patients with adverse and nonadverse pathway conduction. Further, the HRV parameters of preexcitation patients were compared with those of healthy controls.

RESULTS

LF/HF, the best measure of sympathovagal balance, was statistically higher in patients with adverse conduction than in patients without adverse conduction and controls (P  =  0.001). The LF/HF ratio was higher in ventricular preexcitation patients with inducible tachycardia than those without in EPS (P  =  0.001). In addition, the LF/HF ratio was higher in symptomatic ventricular preexcitation patients than asymptomatic ones (P  =  0.001). No difference in HRV parameters was found between preexcitation patients and controls.

CONCLUSION

Autonomic tonus in patients with ventricular preexcitation may affect accessory pathway conduction properties, tachycardia inducibility, and symptomology. The indicator of sympathovagal balance, LF/HF ratio, increased in ventricular preexcitation patients with inducible tachycardia and those that were symptomatic.

Transesophageal and invasive electrophysiologic evaluation in children with Wolff-Parkinson-White pattern

BACKGROUND

Risk stratification for Wolff-Parkinson-White (WPW) pattern either by noninvasive or invasive tests is important to determine whether an ablation is necessary or not. The aim was to compare noninvasive tests and invasive studies in a pediatric WPW population.

METHODS

A total of 71 WPW patients (median age 14 years [interquartile range, 11-16 years]; 43 male) underwent Holter monitoring, exercise stress test (EST), and transesophageal electrophysiological study (TEEPS). In the case of a ≤270-ms effective refractory period of accessory pathway or induction of supraventricular tachycardia using TEEPS, patients were classified as high risk and underwent invasive electrophysiological study (EPS).

RESULTS

Nine of 23 patients with low risk by Holter and eight of 26 patients with low risk by EST had high risk in TEEPS. Risky TEEPS results were detected in 42 of 71 patients and those patients underwent EPS. High-risk characteristic in EPS was detected in seven of nine patients with low risk by Holter and in seven of eight with low risk by EST. Both tests yielded moderate specificity (52-69%) and negative predictive value (61-69%) according to TEEPS.

CONCLUSION

Holter and EST have low predictive value in WPW risk stratification. However, TEEPS and EPS are extremely valuable in WPW risk stratification. TEEPS may reveal important and useful results for WPW risk determination, especially in small children not having undergone EPS in order to avoid its complications.

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.

Evaluation and management of wolff-Parkinson-white in athletes

CONTEXT

Wolff-Parkinson-White (WPW) is a cardiac conduction system disorder characterized by abnormal accessory conduction pathways between the atria and the ventricles. Symptomatic patients classically present with palpitations, presyncope, or syncope that results from supraventricular tachycardia. While rare, sudden cardiac death may be the first manifestation of underlying disease and occurs more frequently in exercising individuals.

EVIDENCE ACQUISITION

Medline and PubMed databases were evaluated through 2012, with the following keywords: WPW, Wolff-Parkinson-White, pre-excitation, sudden cardiac death, risk stratification, and athletes. Selected articles identified through the primary search, along with relevant references from those articles, were reviewed for pertinent clinical information regarding the identification, evaluation, risk stratification, and management of WPW as they pertained to the care of athletes.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 1.

RESULTS

Diagnosis of WPW is confirmed by characteristic electrocardiogram changes, which include a delta wave, short PR interval, and widened QRS complex. Utilization of the electrocardiogram as part of the preparticipation physical evaluation may allow for early identification of asymptomatic individuals with a WPW pattern. Risk stratification techniques identify individuals at risk for malignant arrhythmias who may be candidates for curative therapy through transcatheter ablation.

CONCLUSION

WPW accounts for at least 1% of sudden death in athletes and has a prevalence of at least 1 to 4.5 per 1000 children and adults. The risk of lethal arrhythmia appears to be higher in asymptomatic children than in adults, and sudden cardiac death is often the sentinel event. The athlete with WPW should be evaluated for symptoms and the presence of intermittent or persistent pre-excitation, which dictates further consultation, treatment, and monitoring strategies as well as return to play.

Electrophysiologic Profile and Results of Invasive Risk Stratification in Asymptomatic Children and Adolescents With the Wolff–Parkinson–White Electrocardiographic Pattern

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.

Radiofrequency catheter ablation for dyssynchrony-induced dilated cardiomyopathy in an infant

The relationship between accessory pathway-mediated ventricular preexcitation and left ventricular dyssynchrony-induced dysfunction has been described in patients with Wolff-Parkinson-White (WPW) syndrome in the absence of sustained supraventricular tachycardia (SVT). Supraventricular tachycardia in infants is usually successfully suppressed with antiarrhythmic medications, but catheter ablation has ultimately been required as definitive treatment in medically resistant cases. Catheter ablation has not been described in young infants for dyssynchrony-related dilated cardiomyopathy in the absence of SVT. We describe a case of an infant with WPW who did not have sustained supraventricular tachycardia, but who developed rapid progression of ventricular dysfunction after birth. Preexcitation could not be medically suppressed but was successfully ablated. This was followed by complete resolution of ventricular dysfunction within 2 months.

Cost-effectiveness of various risk stratification methods for asymptomatic ventricular pre-excitation

Accessory pathways with "high-risk" properties confer a small but potential risk of sudden cardiac death. Pediatric guidelines advocate for either risk stratification or ablation in patients with ventricular pre-excitation but do not advocate specific methodology. We sought to compare the cost of differing risk-stratification methodologies in pediatric patients with ventricular pre-excitation in this single institutional, retrospective cohort study of asymptomatic pediatric patients who underwent risk stratification for ventricular pre-excitation. Institutional methodology consisted of stratification using graded exercise testing (GXT) followed by esophageal testing in patients without loss of pre-excitation and ultimately ablation in high-risk patients or patients who became clinically symptomatic during follow-up. A decision analysis model was used to compare this methodology with hypothetical methodologies using different components of the stratification technique and an "ablate all" method. One hundred and two pediatric patients with asymptomatic ventricular pre-excitation underwent staged risk stratification; 73% of patients were deemed low risk and avoided ablation and the remaining 27% ultimately were successfully ablated. The use of esophageal testing was associated with a 23% (p ≤0.0001) reduction in cost compared with GXT stratification alone and a 48% (p ≤0.0001) reduction compared with the "ablate all" model. GXT as a lone stratification method was also associated with a 15% cost reduction (p ≤0.0001) compared with the "ablate all" method. In conclusion, risk stratification of pediatric patients with asymptomatic ventricular pre-excitation is associated with reduced cost. These outcomes of cost-effectiveness need to be combined with the risks and benefits associated with ablation and risk stratification.