P-23 Comparison of Myocardial Damage in Takotsubo Cardiomyopathy and Sympathetic Nerve Distribution Pattern of Myocardium in Human Heart

Background: The cause of takotsubo cardiomyopathy is still unknown. Several mechanisms have been proposed, including neurologically mediated myocardial stunning. Objective:We assessed the relationship between myocardial damage and sympathetic nerve distribution pattern in myocardium in takotsubo cardiomyopathy. Methods: Endomyocardial biopsied specimens in 2 takotsubo cardiomyathy patients with transient left ventricular ouflow tract obstuction were studied. These specimens were evaluated the pattern and area of myocarcdial damage by microscope and electron microscope. We compared these results and nerve distribution pattern in normal human heart that had already been studied by immunohistochemical staining using anti-tyrosine-hydroxylase (TH) antibody for the detection of sympathetic nerve. Results: Hypercontraction of myocardium and cardiac myocyte loss was detected as myocardial damage in the biopsied myocardium of takotsubo cardiomyopathy. These myocardial damages were seen in the small areas and these area patterns were similar to the peripheral TH-positive nerve distribution patterns in the myocardium. Conclusion: These results suggest that myocardial damage may be related to peripheral sympathetic nerve in takotsubo cardiomyopathy.