[Persistent left superior vena cava with agenesis of the right superior vena cava in a patient with complete atrioventricular block].

Persistant left superior vena cava is a rare systemic venous anomaly that can be associated with agenesis of the right superior vena cava. It is usually assymptomatic and discovered incidentally during surgery or other procedures. The authors present the case of a 72-year-old male submitted to an aortic valve replacement surgery. After sternotomy, persistant left superior vena cava and absence of the right superior vena cava were identified. The patient developed complete atrioventricular block after surgery, requiring the implantation of a definitive cardiac pacemaker through the brachiocephalic vein and coronary sinus. This case highlights and ilustrates the clinical implications of the described systemic venous anomalies, discussing the necessary management both in the perioperative and intraoperative periods.