"Apical ballooning" - what is the cause?

The pathophysiology of takotsubo cardiomyopathy remains enigmatic. Here we attempted to define the link between the coronary arteries and the histopathological involvement of the left ventricle. We observed similarities and discrepancies between patients. All patients experienced stress prior to the event. We found a reduced coronary flow reserve in all patients and signs of hibernating myocardium on biopsy specimen. This raises a strong suspicion of stress-induced endothelial dysfunction with hibernating myocardium in the pathogenesis of this cardiomyopathy.