Unresolved questions associated with the management of ventricular preexcitation syndrome

["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.

Comparison of Outcomes of Catheter Ablation in Asymptomatic Versus Symptomatic Preexcitation to Guidelines and Beyond

Management of asymptomatic subjects with preexcitation remains controversial. Our objective was to analyze the reasons an electrophysiological study (EPS) was performed in an asymptomatic population referred for the procedure, and compare the results of catheter ablation between asymptomatic and symptomatic patients. Patients ≥18 years of age with preexcitation referred for an EPS and ablation were grouped as either symptomatic or asymptomatic. We analyzed in both subsets for (1) reasons for the procedure, (2) EPS results (anterograde effective refractory period of the accessory pathway, tachycardia/atrial fibrillation inducibility, anatomical localization), (3) success of the procedure, and (4) incidence of complications. We included 175 patients, 121 of which were symptomatic (39 ± 16 years) and 54 were asymptomatic (35 ± 14 years, p = NS not significant). The most frequent symptoms were palpitations (87%) and syncope (7%). EPS was performed in 44 of 54 asymptomatic patients mainly because of involvement in sports (60%) or high-risk employment (14%). Anterograde effective refractory period was significantly longer in asymptomatic patients (314 ± 55 milliseconds) than in symptomatic patients (278 ± 46 milliseconds; p <0.001). Orthodromic tachycardia inducibility was significantly higher in symptomatic than in asymptomatic patients (69% and 27%, respectively; p <0.001). A total of 170 accessory pathways (49% left free wall, 12% right free wall, 39% septal) were observed without significant differences in the anatomical location between groups. Catheter ablation was attempted in all patients, succeeding in 98% of symptomatic and 95% of asymptomatic patients, without major complications in either group. In conclusion, the reasons for invasive evaluation of asymptomatic patients with preexcitation may be outside the scope of current guidelines. Catheter ablation produces excellent results without major complications.