In 12 patients with coronary artery disease, hypertensive periods during aortocoronary bypass surgery were treated with 1 MAC enflurane. The effect of enflurane on the major determinants of myocardial oxygen consumption was studied. Systolic arterial pressure was reduced to a level of about 120 mmHg (16 kPa). The heart rate diminished by 16.5%. The cardiac index during enflurane application was unchanged. Pulmonary artery wedge pressure was measured at short intervals and remained unchanged. The fall in arterial pressure and heart rate under unchanged preload produced a significant reduction in myocardial oxygen consumption as determined by calculation of the systolic wall tension and the tension time index. In five patients, the O2 content in coronary sinus blood was measured and the arterial-coronary sinus O2 difference was found to be diminished. In the concentration used, enflurane reduced the myocardial oxygen consumption of patients with coronary artery disease.
Ackern et al. (Sat,) studied this question.