We present the case of a 46-year old male patient suffering from non-ischemic cardiomyopathy and intermittent atrial tachycardia. According to guidelines an implantable cardioverter defibrillator (ICD) was planned to implant through the left subclavian vein. During the procedure the angiography revealed a persistent left superior vena cava (PLSVC) with moderate stenosis of the subclavian vein. Due to this we decided not to implant a dual chamber ICD but to implant a single chamber lead with additional atrial sensing capacity. The procedure as well as the follow-up was uneventful. Follow-up revealed good ventricular as well as atrial signals.