Two patients with hereditary telangiectasia (Osler-Weber-Rendu disease) and high-output congestive heart failure secondary to large hepatic arteriovenous malformations had preoperative heart catheterization and exploratory cardiotomy to correct presumed intracardiac left-to-right shunts at the atrial level. At operation, both patients had oxygen-enriched blood returning from the inferior vena cava. Subsequent hepatic angiography demonstrated large hepatic arteriovenous fistulas, and both patients underwent hepatic artery banding and ligation, with reduction of left-to-right shunting.