Atrial Septal Defect

This is the most common atrial septal defect, affecting over two-thirds of people with atrial septal defects. It is caused when a part of the atrial septum fails to close completely while the heart is developing. This causes an opening to develop in the center of the wall separating the two atria.

This defect is part of atrioventricular canal defects and is associated with a split (cleft) in one of the leaflets of the mitral valve.

This defect occurs at the superior vena cava and right atrium junction in the area where the right pulmonary veins enter the heart. As a result, the drainage of one or more of the pulmonary veins may be abnormal in that the pulmonary veins drain to the right atrium, rather than the left atrium.

This defect is located within the wall of the coronary sinus, where it passes behind the left atrium. The coronary sinus carries the blood flow from the heart's own vein, into the right atrium. It is the rarest of all atrial septal defects.

The procedure is named after Willis J Potts (1895-1968), an American surgeon who performed the procedure at Chicago's Children's Memorial Hospital in 1946.

The Potts's (Potts-Smith-Gibon) shunt is a connection between the descending aorta and the left pulmonary artery which was proposed initially as an alternative to the classic Blalock-Taussig's shunt in neonates. This shunt was abandoned because of the high incidence of subsequent pulmonary hypertension, the preferential blood flow to one lung with kinking and distortion of the pulmonary artery and the technical difficulties with takedown.

The Glenn shunt was introduced in 1958 by Dr. William Glenn and modifications to the procedure were published by Dr. Gaetano Azzolina in 1973 . In this procedure, the systemic venous return is re-directed to the pulmonary circulation, bypassing the right heart.

Glenn procedure is performed in cyanotic congenital cardiac anomalies that eventually lead to a single anatomical or functional ventricle (tricuspid atresia), right or left ventricular hypoplasia (hypoplastic left heart syndrome) and as an initial step before the Fontan form of a total right heart bypass.

The classic (unidirectional) Glenn shunt involves ligation of the distal end of the superior vena cava (SVC) and anastomosis of the side of the SVC above the ligation with the distal end of the divided right pulmonary artery, providing unilateral (right) lung perfusion.

In a modified (bidirectional) Glenn or hemi-Fontan shunt, anastomosis is created between the transected end of the SVC and the side of the undivided right pulmonary artery, providing balanced bilateral pulmonary circulation.

The procedure was introduced by William H. Muller, Jr. and J. Francis Dammann, Jr. in 1951 and was initially used in an infant with ventricular septal defect.

Pulmonary artery banding is a palliative surgical procedure used to decrease excessive pulmonary blood flow. It is usually used for neonates and infants with left-to-right shunts unable to withstand complete surgical correction.

Some indications include: single ventricle, multiple VSDs, Atrioventricular Defects, Double Outlet Right Ventricle, Double Outlet Left Ventricle, Unrepaired Transposition of the Great Arteries in neonates to prepare the left ventricle to receive a higher systemic pressure load prior to Arterial switch procedure.