[Myocardial ultrastructure in the recovery period following aortocoronary shunting in chronic ischemic heart disease patients].

On the material from 96 puncture biopsies of the left ventricle performed on 32 patients with chronic ischaemic heart disease during aorto-coronary shunting under extracorporeal circulation with combined cold and pharmacological cardioplegia lasting from 15 to 92 min the ultrastructure of the myocardium has been studied at the 30th-40th min of the restorative period. After restoration of cardiac activity progression of changes in cardiomyocytes was recorded, more clearly seen in the quantitative stereological analysis of the membranous components of mitochondria, the degree of damage depending on the duration of cardioplegia. Statistically significant (p less than 0.02) decrease of the area of external membranes of mitochondria at the 30th min of the restorative period was detected in patients after cardioplegia exceeding 60 min. Such changes are due, according to the authors, both to enhanced demands of energy supply to cardiomyocytes during the overloads of the restorative period and to the disorders of the microcirculation and of the rheological properties of the blood during reperfusion.