[Ultrastructure of myocardial microcirculatory bed in patients with ischemic heart disease at various stages of aortocoronary bypass].

Changes in the ultrastructure of microcirculatory vasculature were studied on 136 puncture biopsy samples of the left ventricular myocardium taken from 56 ischemic heart disease patients before aortic compression, at terminal cardioplegia, and after coronary flow reconstruction. It was found, that changes in the endothelial cells gradually grow during cardioplegia, becoming statistically significant in the reconstructive post-cardioplegia period lasting over 60 min, which affects the capillary permeability, status of homeostasis and metabolism, and contractility of cardiomyocytes in the postoperative period.