The Lewis A. Conner Memorial Lecture

While there are many anatomic varieties of congenital malformations of the heart and great vessels, most may be divided, from a functional point of view, into 3 types: (1) communication between the ventricles or between the aorta and pulmonary arteries, (2) anomalous drainage of pulmonary venous blood into the right atrium, and (3) obstruction to pulmonary venous flow. In each of these categories the responses of the pulmonary vascular tree have to be considered in understanding the altered dynamics. Depending on the type and degree of response in the pulmonary vascular bed, there may be a varying functional picture among patients having the same anatomic or functionally comparable malformation.