Aims: To gain more insight into the phenomenon of Tako-Tsubo cardiomyopathy (TTC), the purpose of the present study was to investigate the myocardial structure in the acute phase of TTC and after functional recovery.
Methods and results: We studied eight patients presenting with TTC diagnosed by coronary angiography, ventriculography, magnetic resonance imaging, and echocardiography. Serial myocardial biopsies were taken during the phase of severely impaired left ventricular function and after functional recovery. Specimens were examined by light and electron microscope as well as immunohistochemistry. Additionally, specific methods detecting different types of cell death and measurements of virus titer were performed. All patients showed the typical contractile pattern of TTC and complete functional recovery within 12 +/- 3 days. In 'acute' biopsies, many vacuoles of different size were found contributing to cellular hypertrophy. PAS staining revealed intracellular accumulation of glycogen. Additionally, structural deteriorations characterized by disorganization of contractile and cytoskeletal proteins could be detected. The extracellular matrix proteins were increased. Signs of oncotic and apoptotic cell death were absent. After functional recovery, all described alterations showed a nearly complete reversibility.
Conclusion: TTC is accompanied by severe morphological alterations potentially resulting from catecholamine excess followed by microcirculatory dysfunction and direct cardiotoxicity. However, the affected myocardium represents a high potential of structural reconstitution which correlates with the rapid functional recovery.