A detailed summary of seven patients who received eight total artificial heart implants, including one Phoenix heart, two Jarvik 7-100 ml hearts, and five Jarvik 7-70 ml hearts, and nine heart transplants, reveals that bleeding, hemolysis, and thromboembolic and infectious problems are not the limiting factors. Size of the patient and the requirement for adequate space to permit adequate systemic and pulmonary venous filling seem to be the major limitations. Patients with a reasonable expectation of receiving a transplantation within 3 weeks are the best candidates for a bridge to transplantation. After this adhesions were found to cause severe technical problems at reoperation.