An elusive persistent left superior vena cava draining into left atrium.

A case report of a persistent left superior vena cava draining into left atrium with a fibromuscular left ventricular outflow tract obstruction and a small atrial septal defect. The anomalous vessel escaped detection during two right and left heart catheterizations from the right arm and open heart surgery. It was an incidental finding during cardiac catheterization from the left arm and the anatomy was confirmed by contrast echocardiography.