Isoflurane in Patients with Ischaemic Heart Disease

Abstract

Isoflurane is a direct myocardial depressant but, when compared with halothane and enflurane it provides improved maintenance of cardiac output [1], Isoflurane causes a dose-related decrease in systemic vascular resistance with peripheral vasodilation, a reduction in pre-load and after-load and in myocardial work and oxygen consumption [2]. Dose-dependent arterial hypotension [3] is the main clinical disadvantage, particularly in the presence of coronary artery disease where there is a limit of tolerance to arterial hypotension. Reiz and colleagues [4] have postulated that, in the presence of coronary artery occlusion, isoflurane-induced coronary artery vasodilation leads to the redistribution of myocardial blood flow and a “steal” phenomenon which may cause ischaemic damage in the region of the myocardium supplied by the stenosed artery. This comparative study was designed to investigate the clinical implications of this theory.