Anesthesiology
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The effects of isoflurane on the transmural distribution of myocardial blood flow distal to an acute critical coronary stenosis and the relationship between the changes in regional blood flow and function were studied to determine whether isoflurane can produce a transmural "steal" phenomenon and to assess the role of this phenomenon in producing changes in regional myocardial function. ⋯ These results show that isoflurane is a coronary vasodilator able to induce a transmural redistribution of myocardial blood flow distal to an acute critical coronary stenosis. A true transmural steal, however, was not produced reliably in the absence of hemodynamic changes, suggesting that isoflurane either is only a moderate vasodilator, or that the decrease in subendocardial blood flow is offset by the negative inotropic action of the drug. When regional myocardial dysfunction distal to a severe coronary stenosis occurs, this correlates with decreasing subendocardial blood flow during isoflurane anesthesia, suggesting ischemia as the cause.