Referenced in: none

Automatically associated channels: Kir2.3

Title: High prevalence of exercise-induced arrhythmias in catecholaminergic polymorphic ventricular tachycardia mutation-positive family members diagnosed by cascade genetic screening.

Authors: Kristina Hermann Haugaa, Ida Skrinde Leren, Knut Erik Berge, Jørn Bathen, Jan Pål Loennechen, Ole-Gunnar Anfinsen, Andreas Früh, Thor Edvardsen, Erik Kongsgård, Trond P Leren, Jan P Amlie

Journal, date & volume: Europace, 2010 Mar , 12, 417-23

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/20106799

Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac disease predisposing to life-threatening arrhythmias. We aimed to determine the prevalence of arrhythmias and efficacy of beta-blocker treatment in mutation-positive family members diagnosed by cascade genetic screening.Relatives of six unrelated CPVT patients were tested for the relevant mutation in the ryanodine receptor-2 gene. Mutation carriers underwent an exercise test at inclusion time and 3 months after the initiation of beta-blocker therapy in the highest tolerable dose. The occurrence of ventricular premature beats, couplets, and non-sustained ventricular arrhythmias (nsVT) were recorded in addition to the heart rate at which they occurred. Thirty family members were mutation carriers and were followed for 22 (13-288) months. Previous undiagnosed CPVT-related symptoms were reported by eight subjects. Exercise test induced ventricular arrhythmias in 23 of the 30 mutation carriers. On beta-blocker treatment, exercise-induced arrhythmias occurred at a lower heart rate (117 +/- 17 vs. 135 +/- 34 beats/min, P = 0.02) but at similar workload (P = 0.78). Beta-blocker treatment suppressed the occurrence of exercise-induced nsVT in three of the four patients, while less severe arrhythmias were unchanged. One patient died during follow-up.Exercise test revealed a high prevalence of arrhythmias in CPVT mutation carriers diagnosed by cascade genetic screening. beta-Blocker therapy appeared to suppress the most severe exercise-induced arrhythmias, while less severe arrhythmias occurred at a lower heart rate.