Rheumatic mitral stenosis in association with parital anomalous pulmonary venous return.

An unusual case is presented, in which mitral stenosis was accompanied by a persistent left superior vena cava communicating through a venous channel with the left pulmonary veins. The pulmonary veins were normally connected to the left atrium, but, due to elevation of the left atrial pressure from the mitral valve lesion, pulmonary venous blood was directed up the left superior vena cava to reach the right atrium. Although from an anatomical viewpoint this did not constitute true anomalous pulmonary venous drainage, the condition behaved as such haemodynamically. It was only at operation that the diagnosis was firmly established, but after mitral valvotomy the abnormal venous channel was obliterated by simple ligation without incident.