BackgroundPlaque rupture with subsequent transient thrombotic coronary occlusion by a fast‐dissolving clot is one of the proposed pathogenic mechanisms in Takotsubo cardiomyopathy (TC).HypothesisThe aim of this study was to seek evidence for the hypothesis of transient coronary thrombosis as the underlying mechanism of TC by means of intravascular ultrasound (IVUS).MethodsIn our database of 63 consecutive patients with TC we identified 10 patients (16%) who had undergone IVUS during their initial left heart catheterisation.ResultsA median length of 67 mm of the left anterior descending artery was analyzed (interquartile range [IQR]: 63.3–70.1 mm). Median lumen diameter, median vessel diameter, median plaque and media volume were 2.9 mm (IQR: 2.7–3.1 mm), 4.2 mm (IQR: 3.8–4.4 mm), and 90.9 mm3 (IQR: 70.4–101.4 mm3), respectively. Plaque rupture, positive remodeling, and presumed intracoronary thrombus were absent in all patients.ConclusionIn conclusion, plaque rupture does not account for the regional wall motion abnormalities observed in TC. The previously reported observation of plaque rupture in TC seems to constitute an incidental finding. We suggest that the theory of aborted myocardial infarction as the underlying cause of TC should be abandoned once and for all. Copyright © 2010 Wiley Periodicals, Inc.