Der Anaesthesist
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[Isoflurane: coronary blood flow and myocardial metabolism in patients with coronary heart disease].
The effects of isoflurane on myocardial oxygen uptake, metabolism and coronary blood flow (argon washin-technique) were studied in 10 patients undergoing three-vessel coronary artery bypass surgery. All patients were men with stable angina and normal left ventricular function and were receiving maintenance doses of beta-receptor antagonists or calcium channel blocking drugs. Anaesthesia consisted of isoflurane and 50% nitrous oxide in oxygen. ⋯ Myocardial uptake of glucose, lactate, free fatty acids and pyruvate significantly decreased after induction and increased to pre-induction levels during sternotomy. Myocardial lactate production, indicating myocardial ischaemia, was observed in 1 patient after induction and in three patients during sternotomy; three additional patients demonstrated a marked reduction in myocardial lactate uptake after induction and during sternotomy. It is concluded that all changes in myocardial metabolism, oxygen uptake and coronary blood flow were the result of a decrease in haemodynamic load on the myocardium and reduced contractility, while the increase in these parameters during sternotomy was due to an increase in myocardial work.(ABSTRACT TRUNCATED AT 250 WORDS)