Pathomorphology of myocardial circulation: comparative study in increased left or right ventricle afterload.

Comparative study of pathomorphology of myocardial circulation under conditions of increased afterload of the left or right ventricles showed similar changes. All compartments of the coronary bed were plethoric, capillary blood stasis and perivascular edema, more pronounced in arterial vessels, were detected in both cases. These changes equally involved both ventricles and the ventricular septum.

Role of sympathetic and parasympathetic nervous systems in heart rate regulation in cats.

The effects of atropine and beta-adrenoceptor blockers on mean HR, wave structure of the cardiac rhythm, and chronotropic reaction to noise stress were examined in cats. Atropine (0.5 mg/kg) increased the mean HR and significantly decreased the spectrum power of HF, LF, and VLF oscillations.

Comparative pathomorphological study of contractile myocardium under conditions of increased left and right ventricular afterload.

Structural changes in the myocardium under conditions of increased left and right ventricular afterload were studied using polarization microscopy and histological, histochemical, and stereological methods. Increased afterload not complicated by heart failure was characterized by low number of damaged cardiomyocytes (3.3-6.

[Histochemical characteristics of adrenergic myocardial and adrenal fibers in experimental narrowing of the aorta and pulmonary artery].

Ligation of the aorta or the pulmonary trunk was the method of experimental overloading of heart ventricles. Histochemical studies indicated activation of mediator chain of the sympatho-adrenal system. Catecholamines content in the nervous plexus of the overloaded ventricle did not change but there was an increase of their content in the medullary layer of the adrenals.

Sympathoadrenal system under conditions of increased left and right ventricular afterload.

Adrenergic plexuses in the myocardium and adrenal medulla were studied histochemically under conditions of increased left or right ventricular afterload. Under conditions of high afterload not accompanied by heart failure the density of sympathetic myocardial innervation remained unchanged in the loaded ventricle, but increased in the intact ventricle. Comparison of the state of the sympathoadrenal system under conditions of increased afterload complicated or uncomplicated by heart failure revealed common prognostically unfavorable changes: sharp decrease in the density of adrenergic nerve plexuses in the ventricular myocardium and activation of adrenal chromaffin cells.