Netlike Appearance Distal to the Moderator Band Shown by Multidetector Computed Tomography May Be a Pathogenesis of Ventricular Fibrillation in Arrhythmogenic Right Ventricular Cardiomyopathy

Abstract

Clinical manifestations of arrhythmogenic right ventricular cardiomyopathy (ARVC) are variable, and in some cases, ventricular fibrillation (VF) represents the first manifestation. In order to aid in the prevention of sudden cardiac death due to ARVC, we examined the clinical presentations of ARVC patients whose first sign was VF or another manifestation. Fifteen patients (male/female 7/8, mean age 47 years, ge of onset 41 years) diagnosed as having ARVC using the updated 2010 Task Force Criteria were included. The earliest symptoms were VF in 3 patients; ventricular tachycardia in 6 patients; heart failure in 3 patients; and ECG abnormality, family history, and premature ventricular contractions in 3 patients. We investigated clinical data based on 12-lead ECG, signal-averaged ECG (SAECG), Holter ECG, echocardiography, right ventricular biopsy, multidetector computed tomography (MDCT), magnetic resonance imaging, substrate mapping using an electroanatomical mapping system, and 123I-metaiodobenzylguanidine scintigraphy for all subjects. Repolarization abnormalities (inverted T waves in right precordial leads) and depolarization abnormalities (late potentials by SAECG) were observed in all patients. We made a remarkable MDCT observation in all patients whose earliest symptom was VF: trabeculae distal to the RV moderator band showed a netlike appearance. The other parameters were similar in patients with and without VF. This particular netlike appearance of RV may be a pathogenesis of VF in ARVC.