Ultrastructure of myocardial capillary endothelium in children with congenital heart disease.

Cardiosurgical stress initiates endothelial injury of the colliquation necrosis type (without activating coagulation necrosis) in coronary capillaries of infants aged under 1 year. The dark cells exhibited high tolerance to operation stress in the presence of labile ultrastructural response of endothelial cells of the main and light types. The percentage of dark cells does not change during surgical intervention, which is a sign predicting a favorable course of the postoperative period.

Anatomical variants of transposition of the main vessels and their relationship with the content of chemical elements in heart ventricles.

Cardiometrical characteristics of anatomical variants of the main vessels transposition are determined by different functional load of heart compartments and are associated with metabolic processes of different intensity, which is confirmed by the content of chemical elements in the right- and left-ventricular myocardium. It was shown that the content of chemicals was virtually the same in both cardiac ventricles in case of main vessels transposition and isolated atrial septal defect. Positive correlations between the degree of left-ventricular hypertrophy and content of S, K, Fe, and Sr in it and a negative correlation between this hypertrophy and Cu content were revealed.

Changes in myocardial metabolism and ultrastructure of myocardial microvessels during pharmacological and cold cardioplegia under hypothermic conditions without perfusion.

A combination of pharmacological and cold cardioplegia in with hypothermia without perfusion in open-heart surgery guarantee the reversible character of shifts in energy and free radical balance in the myocardium. However, this procedure can impair coronary micricirculation due to structural and functional changes in microvessel endothelium. Our results demonstrate that new cytoprotective approaches are extremely needed for cardiac protection during surgery.