Cyanosis, Cardiomegaly, and Weak Pulses

Abstract

An infant was seen at 2 days of age with cardiomegaly, congestive failure, cyanosis, and weak pulses. The primary cardiovascular lesion was a massive arteriovenous fistula between the left subclavian artery and innominate vein. Review of the literature indicates that most newborn infants with large systemic arteriovenous fistulas leading to congestive failure have been cyanotic. The hemodynamic alterations incident to large experimental systemic arteriovenous fistulas affords an explanation for this cyanosis. It is suggested that massive systemic arteriovenous fistula in the newborn lowers systemic resistance to a fraction of the high pulmonic resistance present at this age. The right ventricle bears the brunt of the increased cardiac work. Right ventricular failure associated with a marked increase in systemic venous return to the right atrium elevates right atrial pressure above that in the left atrium and almost inevitably leads to cyanosis with right-to-left shunting of blood through the foramen ovale. Failure to realize that massive systemic arteriovenous fistula in the newborn may present as cyanotic heart disease can cause fatal delay in recognizing this correctable form of heart failure.