Intracardiac echocardiography and electroanatomic mapping in diagnosis of arrhythmogenic right ventricular dysplasia

A 48-year-old man with an episode of syncope and family history of sudden cardiac death was evaluated. The ECG showed negative T waves from V1 to V3 with evidence of epsilon-wave. Magnetic resonance imaging showed replacement with fibrofatty tissue in midapical regions of free wall of the right ventricle with dyskinesia. Transthoracic echocardiography revealed only mild enlargement of the middle right ventricular cavity. A programmed ventricular stimulation induced only an unsustained monomorphic ventricular tachycardia. Intracardiac echocardiography showed mild right ventricular enlargement and outflow dilatation (26 mm), microaneurysms with systolic bulging along the apical segment of the right ventricle. Bipolar voltage mapping, performed by the Carto system, detected a circumscribed low potential (