Combined therapy with subcutaneous implantable cardiac defibrillator and leadless pacemaker in a patient with persistent left superior vena cava and mega coronary sinus: A challenging case for the best treatment.

In a patient requiring pacing and defibrillation therapy, but without superior venous access, combined therapy with S-ICD and leadless pacemaker could be the best solution. An appropriate programming of both devices represents the technical challenge in order to avoid inappropriate shocks due to leadless pacing oversensing.