Mechanism of congestive heart failure following aorta constriction in rabbits.

Severe constriction of the abdominal aorta in rabbits caused congestive heart failure and death in 4 to 7 days. Expansion of total plasma volume suggested that aortic narrowing increases the vascular bed distal to the stricture. Reduction of total body fluids did not prevent total plasma volume expansion, unless it caused severe dehydration. A large percentage of dietary sodium was retained. Expansion of extracellular volume occurred even when sodium intake was reduced. The early, gradual post-operative rise in arterial pressure probably depends, in part, on development of an effective circulating plasma volume. A tentative answer is given to the question of what factors determine the exact time that heart failure will occur.