Enlargement of the right ventricle using a viable atrial pedicle graft

A viable muscle pedicle of right atrial wall was used to enlarge the right ventricle in 5 dogs. The procedure consistently resulted in an increase in right ventricular circumference of approximately 20%. Although ventricular function was adequate to permit survival, cardiac index did not increase appropriately to an elevation in preload. Morphologic studies demonstrated later scarring and thickening of the muscle pedicle suggesting the graft had not maintained its contractile nature.