Comparative studies of ventricular ejection phase parameters for the detection of impaired cardiac function.

Experimental studies were carried out in 11 anesthetized pigs in order to compare the sensitivity of left ventricular ejection phase parameters as determined by quantitative angiocardiographic methods, for detection of mild or moderate ventricular dysfunction. The experimental setup implied various degrees of nonadequate muscular hypertrophy in relation to chronic volume overload by aortic insufficiency. Left ventricular stroke volume, flow, ejection fraction and mean circumferential fiber shortening did not demonstrate impairment of ventricular function reserve when studied in the resting state of the circulation, but became indicative to some degree by their abnormal pattern of response to acute afterload stress (angiotensin infusion). Mean normalized systolic ejection rate as well as normalized values of systolic ejection time were found to be the most sensitive indices of ventricular function in this study.