We report the case of a dual-chamber cardioverter defibrillator (ICD) implantation in a young patient with a persistent left superior vena cava. The patient had biventricular dilatation, pulmonary hypertension and severely depressed left ventricular ejection fraction due to non-ischemic cardiomyopathy. Appropriate use of currently available, low profile active fixation leads allowed safe implantation of both leads through the left subclavian vein.