Clinicopathological Characteristics of Left Ventricular Myocardium with Transient Asynergy: Report of Three Cases

The aim of the present retrospective study was to clarify the histopathologic substrates of left ventricular myocardium with transient asynergy due to acute ischemic insult in man. Three patients who had had prolonged chest pain, new abnormal Q waves and new ST segment elevation were studied. There was no significant elevation of serum creatine phosphokinase activity in two of the three patients. Echocardiograms on admission or the next day showed severe hypokinetic or akinetic motion and thinning of the anteroseptal and apical portions of the left ventricle and regional dilatation of the same portions. Disappearance of the abnormal Q waves, ST segment elevation resolution, and early T wave inversion were observed later. Complete improvement of the echocardiographic abnormalities was confirmed after a few weeks in all patients. Manifest ischemic lesions of subendocardial scars of the anteroseptal region of the left ventricle were detected in only one of the three cases by gross examination. However, on microscopic examination, islands of necrotic myocytes were interspersed with islands of viable cells throughout the jeopardized region in one case, although the scattered necrotic foci were restricted to the subendocardium and the trabeculae. Normal myocardium and subendocardial scars were observed in the other two cases. In conclusion, left ventricular myocardium with transient asynergy, detected clinically during acute ischemic attack, consists of normal myocardium or small ischemic lesions primarily in the subendocardium.