Production of Acute Experimental Circulatory Failure by Graded Pulmonary Artery Constriction.

Abstract

An exptl. attempt was made to simulate acutely the cardinal circulatory changes of congestive heart failure for the purpose of creating a prepn.in which the incipient effects on renal function could later be studied. Optically recorded pressure pulses from the aorta, pulmonary artery, and right atrium are presented, and show that judicious compression of the pulmonary artery can reduce the output of the left ventricle significantly without incurring a drastic fall of arterial pressure. These dynamic studies also revealed that such graded pulmonary artery constriction results in (a) a reduction of pulmonary systolic and diastolic pressures distal to the constriction, and the development of a systolic murmur, (b) a rise in maximal and initial tensions in the right ventricle, and (c) an elevation of right atrial pressures. In some instances, relative tricuspid insufficiency developed. The elevation of central venous pressure is obviously associated with translocation of a large volume of blood to the venous side of the circulation. A part of this transfer occurs from the pulmonary vascular bed, although a shift may also occur within the systemic circuit itself toward the central . veins.