[Experimental study of optimal driving mode in biventricular assist device].

It has been known that the ventricular assist device (VAD) is effective in profound ventricular failure refractory to conventional drugs and the intra-aortic balloon pumping. The patients with biventricular failure required biventricular mechanical support for survival. Until recently, biventricular assist device (BVAD) were applied in a few instances unfortunately. In this experimental study biventricular failure was induced by pulmonary artery banding and ligation of left anterior descending coronary artery in 20 pigs, and the BVAD was operated and the optimal driving mode was examined on the flow ratio of the right and left pumps. Group I animals were treated with BVAD, in the condition pump flow ratio right ventricular assist device (RVAD): left ventricular assist device (LVAD) = 1: less than 0.5 (4 pigs), group II were RVAD:LVAD = 1:0.5 less than or equal to less than 1 (8 pigs), and group III were RVAD:LVAD = 1:1 less than or equal to (8 pigs). CVP and RVEDP were decreased by operating the BVAD in all groups. In the group I, the flow of LVAD was less than a half of that of RVAD and the condition of excess left ventricular preload was elicited, and left ventricular failure was accelerated and it was difficult to maintain the systemic circulation. In contrast, in group II and III, the left ventricular preload was decreased, and left ventricular failure improved, and it was maintain the systemic circulation. PCWP/CVP was calculated as a method to determine clinically the right and left pump flow.(ABSTRACT TRUNCATED AT 250 WORDS)