RESUMO
Diseases of the cardiovascular system are a major health-care problem. Nearly 50% of all deaths are due to cardiovascular disease. A number of cardiovascular patients experience heart failure, mostly of the left ventricle, and require some form of mechanical support. Cardiac-assist devices are used widely in the treatment of patients with damaged heart muscle. Cardiac-assist devices have been introduced recently to maintain circulation in heart failure patients, until a suitable heart transplant donor is found. Earlier types of left ventricular assist devices were the copulsation and the counterpulsation pumps, which increased the efficiency of the vascular system and decreased the workload on the failed heart. In this study, the authors investigated the performance of a valveless cardiac assist device that can be operated in copulsation, counterpulsation, or any intermediate mode with the left ventricle. The device has only one connection to the ascending aorta, no valves, and a common inlet/outlet. The authors measured the hemodynamic parameters in all modes and have suggested an optimal mode of operation in a left ventricular heart failure mode.