| Abstract: | The purpose of the study was to investigate the character of clinical and functional manifestations of ischemic cardiac dysfunction in patients with idiopathic coronary microangiopathy, and their correlation with insulin level, as a possible diagnostic criterion of coronary heart disease (CHD). The subjects were 115 men, including 35 individuals (mean age 41.8 +/- 1.2 years) with microvascular form (MVF) of coronary artery lesion, 60 patients with CHD with postinfarction cardiosclerosis (PICS), and 20 healthy individuals. Patients with glucose tolerance disorder, diabetes mellitus, arterial hypertension, and other severe pathology were not included in the study. The diagnostic tests included selective coronaroventriculography with right ventricle endomyocardium biopsy, and myocardial perfusion scintigraphy. Parameters of coronary, intracardial and system hemodynamics were evaluated; insulin and glucose serum levels were measured at rest and during stress-tests with physical exercise. Endocardial biopsy in MVF patients found plastic insufficiency of the endothelium of hemocapillars, prearteriols and cardiomyocytes. Alterations in the parameters of metabolism, intracardial and system hemodynamics, and physical exercise tolerance were found to be comparable in MVF and PICS patients. Insulin level at rest in both groups was equal to that in the control group. At threshold physical load during veloergometry insulin levels in MVF and PICS patients demonstrated comparable elevation (222.8% and 201%, respectively; p < 0.05-0.01). Glucose concentrations in patients with microangiopathy decreased by 28% (p < 0.05), while in patients with CHD it increased significantly by 27.3% (p < 0.05). The study shows that structural and functional lesion of hemocapillar endothelium underlies cardiac syndrome X It results in perfusion ability impairment, chronic hypoxia, impairment of myocardial contractility under the conditions of physical activity. Hyperinsulinemia, manifesting when ischemia is induced, is not caused by insulinresistence. Probably, it presents and adaptive and compensatory reaction to increase of myocardial glucose requirement, and may be one of early CHD markers. |
