Sixty-six long-term experiments were performed on animals (65 calves, 1 goat) after implantation with a total artificial heart (TAH). Animal survival ranged from 30 to 314 days using TAH devices ranging from the TNS-BRNO-II to the TNS-BRNO-VIIII. In these experiments some basic problems were studied which need to be overcome to achieve the optimal physiological status of the animal, the optimal maintenance of the internal environment, and the long-term survival of TAH recipients. The problem areas studied were: the vasomotor regulation of the periphery, the prevention of calcification of the driving diaphragms, the optimal regulation of homeostasis, and the pathogenesis and prevention of infection. The basic precondition for the experiments was the problem-free implantation of a TAH and the subsequent optimal method of postoperative care was investigated. By the gradual multifactorial solution of these individual problems, the prolongation of the survival period of experimental animals was achieved. The definite solution and elucidation of some complications during long-term survival is still an open problem because the multifactorial events that influence long-term TAH survival are often very complicated and can sometimes only be solved by overcoming numerous obstacles as a result of the deep functional interrelationships of the disorders present.