Factors Influencing the Peak Acceleration of Ventricular Ejection Blood Flow in the Conscious Dog

Abstract

Rushmer suggested that the ventricle acts as an impulse generator and the "initial ventricular impulse" can be used as a useful index of myocardial performance(Rushmer, 1961). This view was further supported by Noble et al. (Noble, 1966) from the observation of the high sensitivity of the maximum acceleration of the blood flow in the early ejection phase to intracoronary injection of stimulating drugs, prior to any changes in stroke volume. Based upon these observations, the peak acceleration of the blood flow in the ascending aorta was proposed as an index of the contractile state of the left ventricle. On the other hand, Wilcken and his co-investigators observed that the peak acceleration was changed with the alterations in aortic impedance (Wilcken, 1964). In this case, the peak acceleration cannot represent the intrinsic left ventricular contractile state. To evaluate the above conflicting results, we performed animal experiment using a conscious dog, and then, studied quantitatively the hemodynamic factors influencing the peak acceleration of aortic flow using the equivalent circuit analysis of the left ventricle-systemic circulation model.