Until recently, the use of
nitroglycerin in patients with acute
myocardial infarction has been contraindicated primarily because of possible
hypotension or
tachycardia which, with sublingual or oral preparations, would be difficult to control. The introduction of intravenous
nitroglycerin and its use during experimentally induced
infarction paved the way for its use in patients with acute
myocardial ischemia. It was shown that
nitroglycerin, administered intravenously during experimentally induced coronary artery occlusion, redistributed flow to the subendocardium of the ischemic area while it maintained flow to the normal areas and was associated with decreased S-T segment elevation. Preliminary studies in patients with acute
infarction have confirmed the beneficial effect of intravenous
nitroglycerin on S-T segment elevation, and a subsequent study in 31 patients with acute
infarction showed a decrease in
infarct size with improved hemodynamics. In a more recent randomized prospective study in 85 patients with acute
myocardial infarction, we found that intravenous
nitroglycerin was associated with a decrease in
infarct size in patients with inferior
infarction (36 percent reduction, p less than 0.05) but that it had no effect on
infarct size in patients with anterior
infarction. Whether or not
nitroglycerin should be used routinely for reduction of
infarct size remains to be determined, but results indicate that it is effective and safe for the treatment of
cardiac failure in patients with acute
myocardial infarction.