THE USE OF coronary vasodilators in the treatment of acute myocardial infarction has been considered by some authors to be physiologically unsound, since hypotension frequently accompanies their use.1Seemingly, if a specific coronary vasodilator were available to adequately dilate coronary vessels without an associated systemic hypotension, such a drug would be both beneficial and useful. The supply of oxygenated blood provided to a region of ischemic myocardium through collaterals probably could be increased, and the danger of ventricular fibrillation lessened. In spite of the paradoxical lowering of blood pressure with the use of nitrates, a few authors continue to advocate their use in humans during acute myocardial infarction. Isosorbide dinitrate (Isordil) is claimed to be a potent coronary vasodilator, and, because of its rapid absorption and prolonged action appears potentially more useful than some other nitrates.2,3 Hedges et al4recently suggested possible benefits with isosorbide dinitrate in