ORIGINAL ARTICLES Hemodynamic Alterations and Regional Myocardial Blood Flow During Supraceliac Aortic Occlusion in Dogs With a Critical Coronary Stenosis

The hemodynamic consequences and myocardial blood flow alterations associated with cross-clamping of the thoracic aorta were studied during pentobarbital (control), halothane (1 MAC), and isoflurane (1 MAC) anesthesia in dogs with a critical stenosis of tho left circumflex coronary artery. Aortic clamping at the fevef of the diaphragm resulted in significant and equivalent increases in mean aortic pressure and left atrial pressure during the control clamp, halothane clamp, and isoflurane cfamp periods. Likewise, aortic clamping resulted in a signifkzmt and equivalent decrease in cardiac output during control-clamp, halothane clamp, and isoflu-rane clamp. Myocardial contractility as assessed by dP/dt was depressed during halothans and isoflurane anesthesia when compared with control, but no further change in S URGICAL REPAIR of aortic aneurysms or occlusive disease requires occlusion of the aorta above the sit