Acute myocardial infarction with normal coronary arteries: a possible manifestation of the billowing mitral leaflet syndrome.

The findings in four young patients with the billowing mitral leaflet syndrome who presented with evidence of acute myocardial infarction are reported. Because technically adequate coronary arteriograms demonstrated patent vessels and the electrocardiograms initially showed pronounced elevation of the ST segments as occurs in Prinzmetal's angina, it is postulated that spasm of normal coronary arteries was the operative factor. Scrutiny of those cases of clinically apparent ischemic heart disease with normal coronary angiograms is suggested to establish whether there is in fact a causal relationship with the billowing mitral leaflet syndrome.