Physiologic Support of Heart Action

DURING the past decade there has been increasing interest in methods of assisting the circulation of patients in circulatory failure. This review traces the development of synchronous types of circulatory assist and, in the last section, reports the progress to date in cardiac pacing by bigeminal electrical stimulation.Approaches to assisting the circulation fall into three major categories. In the first, the work of the heart is lessened by reduction of the amount of blood that the ventricle must eject (that is, the preload); this is referred to as shunt or flow assist because part of the circulation is diverted . . .