Primary coronary artery dissection: its incidence, mode of the onset and prognostic evaluation.

The incidence, mode of the onset and prognosis of primary coronary artery dissection in 1,445 consecutive patients with myocardial infarction undergoing coronary angiography were elucidated in the present study. Primary coronary artery dissection was observed in four patients (0.28%). The first case was a 28-year-old man, who developed angina at rest, followed by inferior myocardial infarction. His coronary angiogram showed dual lumina in the proximal to distal segments of the right coronary artery, which were separated by a flap. A left ventriculogram showed severe impairment of contraction (akinesis) in its inferior segment. Six years later, he was classified as New York Heart Association (NYHA) functional class I. The second case, a 54-year-old man, developed vasospastic angina followed by inferior myocardial infarction. His coronary angiogram showed a similar dissection from the proximal to distal segments of the right coronary artery. A left ventriculogram showed akinesis of the inferior segment and a coronary angiogram five years later showed marked resolution of the dissection. Twelve years after the infarction, he was classified as NYHA functional class I. The third case, a 46-year-old woman, experienced sudden onset of inferior myocardial infarction. Her coronary angiogram showed dissection from the middle to distal segments, and the posterior descending branch of the right coronary artery. A left ventriculogram showed akinesis of the inferior segment, and three years later, she was asymptomatic. The fourth case, a 28-year-old woman, developed anterior myocardial infarction following delivery. Her coronary angiogram revealed dissection from the proximal to middle segments of the left anterior descending artery. A left ventriculogram showed akinesis in the anteroseptal segment and dyskinesis in the apical segment. She died suddenly four years after her myocardial infarction. Thus, primary coronary artery dissection is not extremely rare and it may have been associated with coronary vasospasm in at least two of these four cases.