The quadricuspid aortic valve.

The quadricuspid aortic valve is a very rare congenital defect that may be an isolated entity or associated with a multitude of cardiovascular abnormalities. Isolated cases usually manifest late in life with the complication of aortic regurgitation, which can be delayed by early valve replacement. We present a case of quadricuspid aortic valve associated with truncus arteriosus, ventricular septal defect, and interrupted aortic arch.