Flecainide reduces ventricular arrhythmias via a mechanism that differs from that of β-blockers in catecholaminergic polymorphic ventricular tachycardia

A Case Report of Elective Bilateral Proximal Intercostal Blocks Used to Prevent Arrhythmia in Catecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmogenic disorder characterized by episodes of polymorphic ventricular tachycardia. Clinically, patients who have CPVT present with juvenile sudden death or stress-induced syncope. We present a case of an 18-year-old girl with CPVT resistant to traditional pharmacotherapies. Instead of a typical stellate ganglion block (SGB), the patient underwent bilateral continuous proximal intercostal blocks that successfully inhibited arrhythmogenic events. This therapeutic method may provide an alternative to SGBs and demonstrates proof of concept for an early elective intervention to be included in the diagnostic and therapeutic algorithm for patients with CPVT.

Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) Associated With Ryanodine Receptor (RyR2) Gene Mutations - Long-Term Prognosis After Initiation of Medical Treatment

BACKGROUND

The long-term prognosis of cardiac ryanodine receptor (RyR2) positive catecholaminergic polymorphic ventricular tachycardia (CPVT) patients after initiation of medical therapy has not been well investigated. This study aimed to assess the recurrence of fatal cardiac event after initiation of medical therapy inRyR2-positive CPVT patients.

METHODS AND RESULTS

Thirty-fourRyR2-positive CPVT patients with a history of cardiac events were enrolled. All patients had medical treatment initiated after the first symptom or diagnosis. Exercise stress tests (ESTs) were performed to evaluate the efficacy of the medical therapy. Even after the initiation of medical therapy, high-risk ventricular arrhythmias (VAs), including premature ventricular contraction couplets, bigeminy, and ventricular tachycardia, were still induced in the majority of patients (80.6%). During 7.4 years of follow-up after the diagnosis, 7 of the 34 (20.6%) patients developed fatal cardiac events. Among those 7 patients, 6 (85.7%) were not compliant with either exercise restriction or medication therapy at the time of the events.

CONCLUSIONS

Even after initiation of medical treatment, high-risk VAs were induced during EST in mostRyR2-positive CPVT patients. Most fatal recurrent cardiac events occurred in patients who were noncompliant with exercise restriction and/or medical therapy. Medical management including strict exercise restriction should be emphasized to prevent recurrent cardiac event in mostRyR2-positive CPVT patients. (Circ J 2016; 80: 1907-1915).