The Relationship Between Electrical and Mechanical Events in the Cardiac Cycle of Man

In studying the dynamics of the heart beat, the relationship between electrical and mechanical events in the cardiac cycle has been of fundamental im- portance. The basic concepts of this relationship have been defined by Lewis (1925) and Wiggers (1923) and their co-workers. Sir Thomas Lewis provided indirect information on these events in the right auricle of man. Animal experiments, supplemented by such indirect information as could be obtained from venous and arterial pulse wave trac- ings, recording of heart sounds, etc., in man were used .by Wiggers to anticipate the probable normal sequence of events in the cardiac cycle.