Postsystolic Myocardial Augmentation: 1. Effect Upon an Induced Shock State.

Abstract

Technic and appropriate equipment is reported which removes blood from the circulation during cardiac systole, thereby reducing intraventricular systolic blood pressure and work of systolic ejection. Blood is reinjected during ventricular diastole, so that diastolic blood pressure and coronary blood flow are increased. An electronic circuit enables the phasing of the augmenting systole to be accurately placed in relationship to the QRS complex of the ecg. Application of the technic has been carried out in animals subjected to an induced shock state produced by administration of norepinephrine combined with removal of 1/3 of the circulating blood volume. This procedure is uniformly fatal within 2 hours. Survival time of animals thus prepared is increased by application of the procedure, and the dilated heart and hypotensive state of the standardized animal are reversed.