Effects of nitroglycerin upon myocardial metabolism after open heart surgery

The effects of intravenous administration of nitroglycerin (TNG) on hemodynamics and myocardial metabolism after open heart surgery were evaluated in 22 patients without ischemic heart disease. On 12 hours after starting the continuous infusion of TNG at a rate of 0.2 micrograms/kg/min on 10 patients (TNG group), coronary blood flow (CBF) increased (p less than 0.01) and myocardial oxygen metabolism improved remarkably. However, anaerobic metabolism still existed in TNG group and no significant difference between TNG group and Control group even after 12 hour continuous drug infusion. From these studies, it was concluded that the intravenous administration of TNG at a rate of 0.2 microgram/kg/min increased CBF, however did not improve myocardial metabolism after open heart surgery possively probably because of changes in coronary collateral function.