Cardiovascular Function during Sustained +Gz Stress. 1. Coronary Hemodynamics, Left Ventricular Function and Blood Oxygen Saturation.

摘要

Using a canine model, the heart and cardiovascular system were instrumented to continuously measure coronary blood flow, cardiac output, left ventircular and aortic root pressure, and oxygen saturation in the aorta, coronary sinus, and right ventricle. The animals were exposed to acceleration profiles up to +6 Gz, 120 s at peak G; a seatback angle of 45 was simulated in some experiments. Radiopaque contrast medium was injected to visualize the left ventricular chamber, coronary vasculature, aorta, and branches of the aorta. The results suggest mechanisms responsible for arrhythmias which may occur, and subendorcardial hemorrhage which has been reported in other animals.