Myocardial infarction temporally related to ephedra--a possible role for the coronary microcirculation.

Myocardial infarction has been reported with ephedrine and pseudoephedrine use. It has been suggested that these agents may induce coronary artery spasm, hypercoagulable states, or oxygen demand imbalance. We report a 25-year-old male with myocardial infarction after receiving a diet pill containing ephedra. Coronary angiography revealed normal coronary arteries with very slow flow, suggestive of microcirculation abnormalities. The flow responded promptly to intracoronary verapamil.