Cardiovascular Effects of Acutely Produced Anemia in the Normal Dog

Abstract

Acute isovolemic anemia was produced in dogs anesthetized with Na pentobarbital. When a critical level of anemia was produced, further decreases in hematocrit produced proportional increases in cardiac output. This increase in cardiac output was not accompanied by an increase in right auricular pressure; in fact, in some expts. a decrease in right auricular pressure was observed concomitant with an increase in cardiac output. With restoration of the hematocrit to normal value, the cardiac output decreased to normal levels with no significant change in the right auricular pressure or other indices. It is concluded that the arterial-O2 content is the primary factor in the regulation of the cardiac output in the intact animal.