Intermittent ventricular preexcitation in children: not always a low-risk condition

67 paediatric patients with symptomatic or asymptomatic intermittent ventricular preexcitation (IVP), median age 14 years (IQR 11.2–16.6), 64.2% male, all with normal cardiac anatomy except for one with an isolated bicuspid aortic valve.

Invasive risk stratification using electrophysiological testing (EPT) both at baseline and after adrenergic stimulus (isoproterenol infusion [ISO] or exercise testing [ET]).

Presence of high-risk electrophysiological parameters, defined as shortest pre-excited RR interval (SPERRI) during atrial fibrillation, shortest 1:1 AP conduction during incremental atrial pacing, and/or AP effective refractory period (AP ERP) ≤ 250 ms at baseline or during ET/ISO.surrogate