The use of a safe and effective artificial heart can be lifesaving for those patients with end stage cardiac disease refractory to inotropic support or intra aortic balloon counterpulsation.
The current status of worldwide total artificial heart (TAR) development programs is reviewed in this paper. A comparison is made of the clinical results from the 33 cases utilizing TAH implantation and the first 30 cardiac transplantation cases. Initial results from former group further encouraged the use of the TAH: five cases represent the first human TAH implants and 28 cases used TAH as a bridge to transplant.
These results suggest that the following conditions must be met for clinically acceptable TAH systems: durable components with good biocompatibility and minimal hemolysis; easy control modes having simple and reliable sensors; smaller component size with good anatomical fit; and totally implantable systems offering patients a good quality of life.
The second major topic discussed pertains to the current status of the TAH development programs at major centers worldwide. The pump designs and materials used at several centers are summarized including the Cleveland Clinic's Biolized pump.
Progress with various types of actuation and TAH control modes were also outlined. The Cleveland Clinic's variable rate mode used with the pusher plate type pumps is described. An adaptation hypothesis relative to TAH implantation, which divided into three stages, includes the confusion stage, the fighting stage and the live together stage, is presented with experimental results.
In conclusion, all the major centers achieved equally feasible results with regard to clinical application of their TAR devices.
Future programs for totally implantable TAR systems, including the Cleveland Clinic's version of an electrohydraulic one piece TAH, are also summarized.
