Po-03-157 activity restriction in pediatric catecholaminergic polymorphic ventricular tachycardia: does it matter what the doctor says?

Catecholaminergic polymorphic Ventricular Tachycardia (CPVT) is a rare inherited arrhythmia disorder characterized by adrenergic-induced polymorphic ventricular tachycardia (VT). Physical activity (PA) restriction was once a mainstay of therapy. Although an individualized, shared decision approach to PA is recommended, the amount activity considered safe remains unknown. To describe 1) the association between PA levels and ventricular arrhythmia scores and 2) the PA levels in relation to Canadian PA guidelines and physician PA recommendations. Patients 8-18 years with CPVT were prospectively recruited from the International Pediatric CPVT Registry. PA levels were assessed via an Actigraph accelerometer (GT3X) worn for ≥ 10-hours a day for 7-days. Ventricular arrhythmia score was ascertained from treadmill tests (to volitional fatigue) by an established scale (1=no ectopy or premature ventricular complexes (PVCs), 2=bigeminy, 3=couplets, 4=non-sustained VT). The association between ventricular arrhythmia and PA metrics were controlled for medication doses. A total of 26 pediatric CPVT patients (median age 14 (IQR 11-17) years; 46% females) were included. Nine (35%) patients were on BB monotherapy, 15 (58%) BB and flecainide and 2 (8%) were on no medication. Of those on medication, 3 (12%) underwent left cardiac sympathetic denervation. Median ventricular arrhythmia score among all patients was 2 (IQR 1-2); 11 (42%) had no ectopy or isolated PVCs on treadmill. Moderate-to-vigorous PA (odds ratio: 0.98, 95% CI: 0.95-1.0, p=0.31) was not associated with ventricular arrhythmia scores after adjusting for medication. Median moderate-to-vigorous PA was 44 (IQR 29-59) min/day and only 5 (19%) patients met PA guidelines (≥60 min/day in healthy children). Adolescents were less active than younger children (rho=-0.44, p=0.03), and moderate-to-vigorous PA did not differ based on sex (p=0.18). Physician PA recommendation ranged from no restrictions in 14 (54%) to partial PA restrictions (no competitive, team sport and/or endurance PA) in 12 (46%) patients. Ventricular arrhythmia scores (Figure 1; p=0.42) and moderate-to-vigorous PA (p=0.41) did not differ based on physician PA restrictions. There was no association between amount of PA and clinical ventricular arrhythmia scores in this cohort of predominantly treated CPVT children. Only a fifth of patients met PA guidelines irrespective of physician recommendations, and a large proportion continue to be restricted from PA.