[Left superior vena cava: a simple diagnosis by transthoracic echocardiography. A case report].

Persistent left superior vena cava is an anomaly of the systemic venous return occurring in 0.5% of the general population. We report the case of a patient with an incidental diagnosis made during a dyspnea while he had chronic pulmonary disease. The diagnosis was suspected by the presence of a markedly dilated coronary sinus and confirmed by a simple contrast injection into the left antecubital vein. Transesophageal echocardiography and magnetic resonance imaging confirmed the existence of 2 superior vena cava with the left superior vena cava draining into the coronary sinus. This congenital anomaly is of minimal hemodynamic significance when isolated. The diagnosis can be useful for placement of central catheters from left superior approach.