Background Peculiar asynergy, which consists of hypokinesis or akinesis from the mid portion to the apical area and hyperkinesis of the basal area on contrast left ventriculogram, is rare. Because the end-systolic left ventriculogram looks like a “tako-tsubo,” which was used for trapping octopuses in Japan, we proposed the term “tako-tsubo-like left ventricular dysfunction.” Our aim was to evaluate its clinical features and causes. Methods We studied 30 patients with tako-tsubo-like left ventricular dysfunction without significant coronary artery disease. We assessed its pathophysiologic mechanisms by coronary spasm provocation test, endomyocardial biopsy, measurement of virus titer, and measurement of circulating catecholamine levels. Results Patient age ranged from 55 to 83 years. Twenty-eight were women and 2 were men. Tako-tsubo-like left ventricular dysfunction was dramatically resolved on predischarge left ventriculogram at 11.3 ± 4.3 days. Acute coronary angiography revealed spontaneous multivessel coronary spasm in 3 patients. Among 14 patients, ergonovine or acetylcholine induced epicardial single coronary spasm in 4 patients and multivessel coronary spasm in 6 patients. Spontaneous microvascular spasm occurred at predischarge in 1 patient. An endomyocardial biopsy specimen in 3 patients and measurement of virus titer in 7 patients did not show evidence of acute myocarditis. Circulating norepinephrine was normal or slightly elevated in 6 patients. Conclusions We showed clinical features of a novel cardiac syndrome with tako-tsubo-like left ventricular dysfunction. Although the precise cause remains unclear, simultaneous multivessel coronary spasm at the epicardial artery or microvascular levels may contribute to the onset of tako-tsubo-like left ventricular dysfunction. (Am Heart J 2002;143:448-55.)