The arterial supply to the right atrium and the sinus node in classic tricuspid atresia.

Dissection was performed in 41 hearts from patients with classic tricuspid atresia so as to demonstrate the major arteries supplying the right atrium and the sinus node. A right anterior atrial artery was identified in 85.4% of the hearts, a right lateral atrial artery was seen in 68.3%, a right posterior atrial artery in 41.5%, and a left anterior atrial artery in 78.0% of the specimens. The artery to the sinus node, identified in 34 hearts, originated from the right coronary artery in 38% of the cases, from the left coronary artery in 59%, and had a dual origin in 3% of cases. The relative importance of these arteries is discussed with regard to the atriopulmonary anastomosis of the Fontan procedure. Special consideration is given to the incisions employed in different variations of this operation and the arterial distribution is compared to that found in the normal heart.