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Clinical significance of abnormal Q wave disappearance in acute transmural myocardial infarction.

1991; Japanese Circulation Society; Volume: 55; Issue: 3 Linguagem: Inglês

10.1253/jcj.55.213

1347-4839

Kinji Ishikawa, MINORU SHIMIZU, Makoto Ohno, Masataka Morishita, Iwao Ogawa, Takahiro Hayashi, YOSHIHIDE SAKAGUCHI, KEIZO YAMASHITA, Hironari Koka, Noriaki Kamata, Ryo Katori,

Cardiac electrophysiology and arrhythmias

The clinical features of acute myocardial infarction patients in whom abnormal Q wave disappeared were analyzed. Of 201 patients, 40 (20%) (Group A) showed disappearance of Q wave in serial electrocardiograms. Regional ejection fraction of the infarcted portion improved significantly (from 24 +/- 2 to 34 +/- 4%, p less than 0.001) during chronic phase in Group A, but no such improvement was present in Group B patients who showed no change in the Q wave. Global ejection fraction was greater and percent akinetic segment was smaller in Group A than in Group B at chronic phase. Coronary occlusion occurred more often at segment 7 in Group A; in Group B, occlusion occurred more frequently upstream at segment 6, suggesting Group A had a smaller area of risk. Spontaneous recanalization was more often (57%) and complete occlusion was less frequent in Group A. These indicate that Group A is characterized by a smaller area of risk, smaller infarct size, earlier reperfusion, and greater improvement in wall motion. Twenty-eight patients (70%) of Group A lost Q wave within one month and 12 patients (30%), after 3 months or more. Electrical stunning of the myocardium may be a possible mechanism for the early disappearance of Q waves, and anatomical healing for the late disappearance of Q waves.