A right ventricular assist device (VAD) based on the principle of counterpulsation has been developed at our institution. The device is a valveless, pneumatically actuated, 40 cc, sac-type pump, with a single inlet-outlet port. For right ventricular support, the "Uniport" pump is anastamosed end-to-side to the pulmonary artery. In previous experimental trials, the device has been shown to impart minimal trauma to blood components. In this study, biventricular failure was induced in eight Holstein calves by normothermic ischemia during cardiopulmonary bypass. A Pierce-Donachy left VAD (LVAD) was used for left ventricular support following the ischemic insult. Hemodynamic measurements were obtained throughout the study, and each animal served as its own control. A significant increase in post injury cardiac output (33.5 +/- 11.4%) was obtained with use of the Uniport and LVAD, as compared to use of the LVAD alone (p less than or equal to 0.005). Other hemodynamic parameters of right heart failure, including right atrial pressure (RAP), pulmonary artery pressure (PAP), and left atrial pressure (LAP) were not significantly affected. These data suggest that the Uniport right ventricular assist device significantly improves cardiac output in this model of moderate right ventricular failure. Additional studies are required, however, to optimize pump stroke volume, and to further define the performance envelope of the device.
Animals Cardiac Output