Exercise related ventricular arrhythmias are related to cardiac fibrosis in hypertrophic cardiomyopathy mutation carriers

Abstract

Aims Hypertrophic cardiomyopathy (HCM) is a frequentcause of sudden cardiac death (SCD) due to exercise-relatedventricular arrhythmias (ERVA); however the pathological substrate is uncertain. The aim was to determine theprevalence of ERVA and their relation with fibrosis asdetermined by cardiac magnetic resonance imaging (CMR) in carriers of an HCM causing mutation.Methods We studied the prevalence and origin of ERVAand related these with fibrosis on CMR in a population of31 HCM mutation carriers.Results ERVA occurred in seven patients (23%) who all showed evidence of fibrosis (100% RVA(+) vs. 58%ERVA(-), p=0.04). No ventricular tachycardia or ventricu-lar fibrillation occurred. In patients with ERVA, the extent of fibrosis was significantly larger (8±4% vs. 3±4%, p= 0.02). ERVA originated from areas with a high extent of fibrosis or regions directly adjacent to these areas. Conclusions ERVA in HCM mutation carriers arose from the area of fibrosis detected by CMR; ERVA seems closely related to cardiac fibrosis. Fibrosis as detected by CMR should be evaluated as an additional risk factor to further delineate risk of SCD in carriers of an HCM causing mutation. © The Author(s) 2011.