The hemodynamic effects of cardiac tamponade: Mainly the result of atrial, not ventricular, compression

Abstract

We studied the hemodynamic effects of surgically induced regional cardiac tamponade in anesthetized dogs. Tamponade restricted to either the right or the left venticle was compared with tamponade of either ventricle and both atria. Intrapericardial pressures were elevated to approximately 20 mm Hg. With tamponade of the right ventricle alone, aortic pressure rose from 161 ± 3.8 to 164 ± 3.4 mm Hg (p > .05) and cardiac output fell from 149.4 ± 16.1 to 134.9 ± 11.9 ml/kg/min (p > .05). However, tamponade of the right ventricle plus both atria decreased mean aortic pressure from 152.5 ± 3.6 to 115.9 ± 8.7 mm Hg (p < .01). With tamponade of the left ventricle alone, aortic mean pressure changed significantly from 158.5 ± 6.1 (control) to 148.9 ± 5.0 mm Hg (tamponade) (p .05). However, when the atria were included, mean aortic pressure fell significantly more from 155.5 ± 5.4 to 105.5 ± 10.4 mm hg (p