Electrophysiological guided accessory-pathway ablation strategy in children with asymptomatic WPW: it may not be enough to prevent sudden cardiac death.

BACKGROUND

Sudden cardiac death (SCD) may rarely occur among asymptomatic patients with Wolff-Parkinson-White (WPW) pattern. Risk stratification is based on electrophysiological study (EPS). We aimed to evaluate long-term efficacy of such a strategy in preventing SCD.

METHODS

Retrospective analysis of asymptomatic children with WPW who underwent EPS using isoproterenol. Patients considered at risk had inducible sustained atrial fibrillation or atrioventricular reentry tachycardia (AVRT) associated with the following: (1) accessory pathway (AP) effective refractory period or (2) 1:1 shortest cycle length along the AP or (3) shortest pre-excited R-R interval during AF ≤ 250 ms.

RESULTS

Fifty-one consecutive cases (7-18 years, 12 ± 3) were identified, 40 (78%) with right and 11 (22%) with left AP. Twenty-eight (55%) were classified as high risk (HI) and 23 (45%) as low risk (LO), with no significant differences in demographic characteristics and AP locations. Ablation was performed in 20/28 HI and 11/23 LO patients (p 0.08), with no significant differences in acute success (20/20 versus 10/11, p 0.17) or recurrence (1/20 versus 2/10, p 0.15). Follow-up (46 ± 27 months): ablated patients remained asymptomatic; among the 23 non-ablated, 18 (78%) remained asymptomatic, 5 (22%) were successfully ablated, and 5 (22%) presented events (4 AVRT, 1 SCD). Arrhythmic events did not differ significantly between non-ablated HR and LR (2/8 versus 3/15, p 0.29) and the SCD was in the LO group.

CONCLUSIONS

More than 50% asymptomatic WPW children present high-risk AP properties. EPS-based risk stratification using isoproterenol was not able to identify increased risk of future events or SCD.