Abstract
We investigated the effects on cardiac performance of the left heart bypass (LHB). Three different LHB mode were used in Mongrel dogs: asynchronous pulsatile, synchronous pulsatile, and nonpulsatile mode. In these modes, the pump flow was changed and then changes in AoSP, LVSP, LAP, CO, PTB, EVR and LVW was simultaneously measured, In asynchronous pulsatile mode the phase analysis was used. The results obtained in these experiments were 1) In high LHB flow, the nonpulsatile LHB was more useful to maintain flow and more effective to reduce the cardiac work than other modes of LHB. However there was no difference between the effects on the cardiac performance when the LHB flow was increased higher. 2) In contrast, when the LHB flow was low, no differential effect were observed between the hemodynamic parameters. Thus, it is concluded that although the cardiac work was reduced in all modes of LHB when the bypass flow was maintained high, the nonpulsatile LHB showed the best performance of all modes of LHB.
