Acute myocardial infarction with "normal" coronary arteries: clinical and angiographic profiles, with ergonovine testing.

Among 528 patients consecutively undergoing selective coronary angiography after acute myocardial infarction, ten cases (1.9%) with angiographically normal coronary arteries were identified. Eight of these ten patients were 45 years of age or younger and comprised 11% of those studied in this age group, with higher prevalence in females (five of 18 [28%]) versus males, (three of 57 [5%]). Common features besides the young age of patients included predominance of female sex, smoking as a risk factor, and the lack of preinfarction symptoms. An ergonovine test was carried out in seven of these patients, and all tested patients failed to show any evidence of focal coronary spasm. Three patients had recanalization of the infarct-related vessel by intracoronary streptokinase. The lack of a history of variant angina in nine patients, the negative response to ergonovine provocation in seven, and documented thrombolysis after intracoronary streptokinase in three seem to indicate that a thrombotic process is a leading factor in myocardial infarction in such cases. Angiographic studies of this young subset of patients would enhance their identification and might reveal the pathophysiologic mechanisms involved with potentially significant clinical implications. Long-term follow-up of such cases will be needed to determine their ultimate prognosis.