Abstract
Recently, there has been much discussion about a hypothesis that there are two kinds of experimental heart failures, namely the one caused by impaired utilization of energy and the other by impaired libera, ion of energy (1-5). Spontaneous failure and many druginduced failures belong to the former group, and such failures induced by metabolic inhibitors belong to the latter. It was pointed out that, in general, cardiac glycosides are effec, ive in the first group of failures, but not in the second, suggesting that the mechanisms of failure are different from each other. In the present study, the authors reinvestigated this problem systematically, using dog's heart-lung preparation.
