Clinical and experimental experiences on assisted circulation with special reference to its indications and optimal flow rate.

1) The different modes of assisted or controlled circulation have been con· sidered for an intractable cardiac failure. The authors advocated the following classification that may be useful for the hemodynamic study of assisted circulation. A) The partial bypass technique: ( 1) veno-arteiral pumping, (2) right ventricular partial bypass, ( 3) left ventricular partial bypass, and (4) partial cardiopulmonary bypass. B) The total bypass technique: (1) right ventricular total bypass, ( 2) left ventricular total bypass, (3) synchronized arterial counterpulsation, and ( 4) total cardiopulmonary bypass. 2) Indication for various types of assisted circulation were discussed on the basis of the clinical and experimental experiences. 3) The authors proposed the concept of an optimal flow rate of assisted circulation employing partial bypass technique. The maximum efficacy of assisted circula· tion may be obtained by perfusing at the optimal flow rate, while the serious complications caused by perfusing at an unnecessarily high flow rate are avoided. The authors previously reported the efficacy of veno-arterial pumping and partial cardiopulmonary bypass on dogs with experimentally induced cardiac failure and on clinical cases of acute pulmonary edema or intractable congestive cardiac failure, the clinical application of a properly designed pumping device "Circulatory Assistor H-1" in these cases, and the hemodynamic and histological studies on the experimental animals in which prolonged venoarterial pumping was performed. On the basis of these observations, an attempt is made in this paper to ~nJcA.t~ ~$. ,NB t~. W7K 1%. cA.!l!t 3lt. ,Nllai:l&:. rz;;~ ~. ~tt't!lit\t. illwl\l!liJ.L, 7K:tt:.lll:ll't Received for publication May 27, 1965.