Structural changes in the myocardium and serum lipid spectrum in experimental hypercholesterolemia and hypothyroidism

We studied the peculiarities of lipid spectrum of the blood and structural reorganization of the myocardium in experimental hypercholesterolemia with and without hypothyroidism. It was found that alimentary hypercholesterolemia accompanied by elevated total cholesterol, LDL, HDL, and triglyceride concentrations led to a decrease in body weight, heart weight, number of cardiomyocytes in the heart and induced pronounced lytic changes in cardiomyocytes, circulation disorders (sludge syndrome, echinocytosis of erythrocytes, lymphostasis), diffuse fibrosis of the stroma, and appearance of foam cells among diffuse mononuclear infiltrate cells. The combination of hypercholesterolemia with hypothyroid status caused more pronounced changes in the lipid spectrum and atherogenic index and more pronounced lytic and necrobiotic changes in cardiomyocytes. These findings suggest that elevated cholesterol concentrations in the blood, especially against the background of suppressed thyroid function, can directly induce considerable damage to cardiomyocytes, intramural vessels, and erythrocytes without the development of myocardial ischemia and in the absence of atherosclerotic plaques.