BACKGROUND AND OBJECTIVES: The so-called 'stress-induced cardiomyopathy' or takotsubo cardiomyopathy, mimicking acute myocardial infarction (AMI), has recently been reported, particularly in Japan. We prospectively studied the clinical characteristics of, for the first time with a Korean series, this novel syndrome. SUBJECTS AND METHODS: Eighteen patients, fore filling the inclusion criteria, were entered onto the study. The criteria for inclusion were: 1) no previous history of cardiac disease, 2) acute onset, 3) a regional wall motion abnormality in the left ventriculogram, typically in the apical segment, and 4) no significant stenosis in the coronary angiogram. RESULTS: The events preceding the condition included: emotional stress (N=7), acute illness (N=5), non-cardiac surgery or medical procedure (N=4) and accident (N=2). Chest pain, dyspnea, or nausea/vomiting were initially noted in 12 cases (66%). Pulmonary edema was demonstrated in 10 (56%), and cardiogenic shock in 4 (23%) of the patients. The peak creatinine kinase MB fraction was 69+/-136 IU/L. A T wave inversion was noted in all patients, whereas, a Q wave was noted transiently in only 1. The average left ventricular ejection fraction (LVEF) was 38+/-8% on the initial echocardiograms. On the left ventriculograms, 15 patients showed akinetic wall motion, or aneurysmal dilatation in the apical wall, however, notably in 3 patients in the mid-ventricular wall. The coronary vasospasm provocation tests were negative in all 10 patients tested. An intravascular ultrasonography showed no infarct-related plaques in the 4 patients examined. On a follow-up echocardiogram, the average LVEF was improved to 51+/-8%, and regional wall motion was normalized after 30+/-29 days following onset. CONCLUSION: We report, for the first time in a series of Korean patients, on a novel stress-induced cardiomyopathy with transient regional wall motion abnormality, mimicking AMI. The precise etiology remains to be elucidated in further studies.