Persistent left superior vena cava as a cause for an unsuccessful ICD implant.

Transvenous ICD implantation has become a routine procedure at cardiologic centers. If such procedures fail because lead placement in the heart is impossible, anomalies of the venous vascular system should be considered. A persistent left-sided superior vena cava (LPSVC) with transition into the coronary sinus (CS) may be a cause of implantation difficulties. We describe the case of a 70-year-old patient, in whom non-invasive evidence of LPSVC was successfully gathered through contrast medium-supported transthoracic and transesophageal echocardiography and magnetic resonance imaging (MRI). System implantation from the right side was performed thereafter without problems.