Sequelae of atriotomy and ventriculotomy on the endocardium, conduction system and coronary arteries.

The endocardium was analyzed in all four chambers of 99 hearts with various types of congenital heart defects in which surgical repair was performed more than 6 weeks before death. The findings were compared with those of normal hearts in similar age groups. In some cases the endocardium was microscopically examined. This study revealed that in many cases all four chambers had fibroelastosis of the endocardium (diffuse regardless of the type of surgery done previously). These data suggest that diffuse fibroelastosis can occur as a result of surgical intervention and may be related to blocked lymphatic drainage. Sudden death in some patients long after surgery for congenital heart disease and the failure of the chambers to regress to normal size in some cases after total surgical repair may be related to fibroelastosis of the chambers. The sinoatrial node may be injured in atriotomy and in the performance of the Mustard procedure. Ventriculotomy may injure the right bundle branch. Ventriculotomy may also injure the coronary supply to the right ventricle or rarely the anterior descending coronary artery.