The Artificial Heart: Research, Development or Invention?

¹ Division of Artificial Organs, Department of Surgery, University of Utah Medical School, University of Utah, Salt Lake City, Utah

we Have learned the lessons of the past and will apply a simple approach. We hope to prove that an artificial heart that responds to Starling's law will be able to maintain an animal's circulation for a long time. Progress made with thrombosis prevention by either heparin grafting or the velour technique—in both of which we have participated—seem to indicate that the prospects of overcoming thrombosis are better now than they were before. To prove our concepts we will need the tools and, therefore we will still make artificial hearts. The major portion of our work, however, is with animals to receive feedback and inspiration. We hope to make a simple artificial heart driven by compressed air which will be introduced thruogh tubes into the chest wall. We have learned from McDonald²³ to anchor the tubes with Dacron in the skin to prevent the occurrence of infection. The inflow resistance of our valves will be low. The ventricles will be collapsible, but not distensable beyond a piont. The result will be an artificial heart that, for its output, will automatically depend on venous filling from both sides—in other words, it will respond to Starling's law. Since careful analysis of our previous experience and those of others has indicated that failure in the past (both in our hands and in those in other laboratories) resulted mainly from technical failures: damage done by heart-lung machines, insufficient venous return, insufficient cardiac ourput. pulmonary complication, air emboli, and quite often technical breakdown of either the heart itself or its driving mechanism, its monitoring system or the leads to it. We will give priority to a simple design, better surgical techniques and to intense postoperative management of our experimental animals. We have in the past learned how to make our own plastic artificial hearts. Close cooperation between the conceptional designer, the mold maker, the thoracic surgeon and the cardiologist is required for a fruitful solution.The recent emphasis on heart transplantation and its temporary success can only stress the fact that there will never be enough human hearts available for transplantation. The alternative approach of the artificial heart deserves to be studied.