Partial extracorporeal circulation in closed-chest dogs

¹ Institute for Medical Research, Cedars of Lebanon Hospital, Los Angeles, California

In anesthetized dogs a fraction of the venous blood flow was diverted into a heart-lung machine (gas exchange bag) and from there infused by gravity into the arterial circulation. During such a partial heart-lung bypass an increase in extracorporeal perfusion rate resulted in a long lasting bradycardia and a decrease of right ventricular pressure and pulmonary blood flow. The decline of the aortic pressure caused by this maneuver could be compensated by adjustment of the infusion pressure into the arterial system. The external work of the heart was reduced thereby without compromising tissue perfusion. The procedure was compatible with survival of the animals.