by Yelena PONIZOVKINA, journalist A group of scientists from the Institute of Immunology and Physiology, the Ural Branch of the Russian Academy of Sciences (Yekaterinburg), headed by Vladimir Markhasin, Corresponding Member of the Russian Academy of Sciences, a specialist in the cardiac biomechanics, well-known both in Russia and abroad, has discovered a new type of myocardial contractility autoregulation connected with myocardial tissue heterogeneity. This result is important for a diagnosis, therapy, and prognosis of cardiovascular diseases, which rank first among the causes of population mortality. The innovational work of physiologists has become one of the most important achievements of the Ural Branch of the Russian Academy of Sciences of recent years. Not long ago scientists believed that myocardial cells--cardiomyocytes--were relatively similar. When numerous data indicated the opposite, the scientists started to speak about myocardial heterogeneity. It was found that the biomechanical, bioelectric, and biochemical characteristics of cardiomyocytes in different regions of the ventricular wall (at the apex or base, in the outer or inner layers) were different, and with propagation of stimulation wave in the heart were stimulated not simultaneously, but in succession. This phenomenon was first discovered in the course of studies of pathological processes, for example, coronary disease or myocardial infarction. Further experiments showed that the normal myocardium was also heterogeneous. Moreover, this property was responsible for the normal work of the main organ of the circulation system, preventing the development of arrhythmia. Due to this the myocardium acquires high plasticity: reduced function of one region of the compartment wall can compensate for stimulation of others. The Ural cardiophysiologists got interested in these effects. In order to understand the role of this heterogeneity in health and disease, a group of specialists ... Читать далее