Replacement of the left ventricle with a single-chambered artificial pump

Early clinical experience with total artificial hearts has stimulated further research and interest in this field. The concept of total heart replacement with a permanent mechanical device has been reevaluated, and its application as a bridge to heart transplantation is becoming more widely accepted. The size of total artificial hearts, however, limits the number of cases in which they can be used. In an effort to solve this problem, we evaluated a single-ventricle artificial pump in six Hereford calves. During surgery, the left ventricle was excised and replaced with a pneumatically actuated polyurethane pump connected to the mitral and aortic valve anulus. The right ventricle provided flow through the pulmonary vasculature, which eliminated the necessity of maintaining elevated right-sided filling pressures. The single-ventricle pump required less space than a biventricular device and was capable of maintaining adequate hemodynamic parameters in experimental animals. In comparison with the biventricular pump, this device offered the advantages of less extensive dissection requirements, ease of anastomosis, and a better anatomic fit. Patients whose pericardial cavities are too small for a biventricular artificial heart may benefit from the single-ventricle pump if they require hemodynamic support while awaiting heart transplantation.