Wall motion abnormalities in Q wave and non-Q wave myocardial infarction in isolated left anterior descending coronary artery disease.

Abstract

Although the frequencies of transmural involvements of Q wave and non-Q wave myocardial infarction (MI) are similar, their clinical features are different in many aspects. In the present study, the wall motion abnormalities of 34 patients with Q wave MI and eight patients with non-Q wave MI, all with isolated left anterior descending artery (LAD) lesion, were compared using left ventriculography and two-dimensional echocardiography. This study clearly demonstrated that the severity and distribution of asynergy were significantly greater in patients with Q wave MI than in those with non-Q wave MI. Akinesis or dyskinesis was observed in all 34 patients (100%) (151 of 544 segments) with Q wave MI, and in four of eight patients (50%) (eight of 128 segments) with non-Q wave MI (p less than 0.05). Apical aneurysm occurred exclusively in patients with Q wave MI. In non-Q wave MI, asynergy was localized at the papillary muscle level or the apex. At the chordal level, asynergy was observed in only one of eight cases with non-Q wave MI, and in 24 of 34 cases with Q wave MI (p less than 0.05). These results suggest that the infarct size may be smaller in non-Q wave MI than in Q wave MI in patients with isolated LAD lesion.