[Ultrastructure of the human heart sinus node in alcoholic cardiomyopathy under acute alcohol intoxication and without it].

An electron-microscopic study of the sinus nodes (SN) was conducted in the hearts of 8 males aged 32-60 who had suddenly died of alcoholic cardiomyopathy in the background of acute alcohol intoxication (4 cases) or without it (4 cases). The hearts of matched-for-age 7 males and 1 female whose cause of sudden death was other than cardiac served as control. It appeared that all the components of the sinus nodes from hearts of the study group underwent chronic or acute destructive changes. The latter were seen both in dark and clear SN conducting myocytes. There were also defects in neurohumoral regulation of the myocytic function due to nervous and microcirculatory SN disturbances. SN connective tissue was affected too. Relevance of the elicited SN changes to cardiac rhythm derangement and to the mechanism of sudden cardiac death is discussed.