Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT)
is a genetic arrhythmia syndrome characterized by
adrenergically-triggered ventricular arrhythmias, syncope, and sudden
cardiac death. Several small studies suggest that atrial arrhythmias
(AAs) are common in patients with CPVT. Objective: To determine the
incidence and type of AAs observed within a large, single-center cohort
of CPVT cases as well as the efficacy and durability of AA-directed
management. Methods: In this retrospective study, the electronic medical
record of 129 patients (52% female; average age at diagnosis 20.8
15.3 years) with CPVT (95% with a putative CPVT1-causative RYR2
variant) between 01/2000 and 09/2019 were reviewed for
electrocardiographic evidence of AAs. Clinical features and efficacy of
pharmacologic and ablation therapy were assessed. Results: Overall,
10/129 (7.8%) CPVT patients, all RYR2 variant-positive, had evidence of
an AA (atrial fibrillation/flutter in 6, atrial tachycardia in 3, and
supraventricular tachycardia in 1). The median age at AA diagnosis was
23 (14.2-35.5) years. 8/10 of patients experienced symptoms attributed
to their AA, including inappropriate shocks. All patients were trialed
on anti-arrhythmics, including -blockers, and/or flecainide. Owing to
drug failure (1/10), drug intolerance (1/10), or patient preference
(2/10); 4/10 patients received an ablation. Over a median follow-up of
23.5 (4.5-63) months, no AA recurrences were observed. Conclusion:
Compared to prior studies, the incidence of AAs in this large,
single-center referral cohort of CPVT patients was substantially lower
(7.8% vs. 26%-35%). Although larger multi-center studies are needed
to confirm, this study suggests that ablation is efficacious and durable
in CPVT-associated AAs.
Flecainide reduces ventricular arrhythmias via a mechanism that differs from that of β-blockers in catecholaminergic polymorphic ventricular tachycardia