Circulatory insufficiency with acquired heart diseases

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Circulatory insufficiency, which should be interpreted as the impossibility of full blood supply of tissues in accordance with the level of sharing that occurs when limited adaptive capacity of the cardiovascular system and to ensure the metabolism starts to use the reserves of other systems, especially the respiratory system. Circulatory insufficiency may occur because of infringements contractility, i.e. by weakening the force of heart contractions and consequently - decrease in cardiac output. This form it can be called a heart failure.
The development of circulatory failure may be due to other factors such as significant changes in tone resistive vessels, decrease volume of circulating blood and oxygen capacity and so on, Some authors, especially often in clinical practice, the distinction between the concept of circulatory failure and heart failure, though, as it is obvious from the above, the differences between them are.
Metabolic requests tissues when changing the currency can be covered at the expense of additional extraction of certain substances from the blood. Quantitative characteristic features of this additional disposal of certain substances involved in the measurement of the blood against the normal values are called safety factor.
The smallest ratio security celebrated in oxygen and glucose (it is equal for these substances 3), while others significantly exceeds the specified value.
That is why when activating metabolism, primarily energy, should immediately increase the blood supply to tissues to provide them with oxygen and glucose. If the circulatory system is unable to ensure adequate exchange perfusion of tissues with blood, and there is an insufficiency of blood circulation, manifested primarily oxygen starvation of tissues (hypoxia), rapid spending of substrates energy metabolism and others associated with this process.
Circulatory insufficiency with acquired heart defects caused by two factors: a decrease in the efficiency of cardiac output due to changes in intracardiac hemodynamics and gradual decrease in contractility.
Before you characterize violations of myocardial contractility with acquired defects and their value in the event of failure, it is advisable to make some remarks about his normal functions.
The normal functioning of the heart caused by close interaction of the following systems: system of myocardial contractile proteins, system calcium regulation of contraction of heart muscle and other
The system of contractile proteins are presented in the myocardium actin, myosin and their complex - actomyosin, forming a group of hard-soluble proteins myofibrils (Banga, Szent-Gyorgyi, 1941; Straub, 1942). In addition, in the heart muscle are easily soluble myofibrillar proteins: tropomyosin and troponin (I. I. Ivanov and others, 1959).
The main structure of the contractile mechanism of myocardial muscle cells are of myofibrils - tertiary intracellular education, peculiar only to muscle tissue. They represent the long strings that without interruption, and then pass sarcomere in sartomer through membranes and end in the sarcolemma (outer shell of muscle fibers) on membranes of the inserted discs or the points of attachment of muscles (Szent-Guorgyi, 1959).
Huxleu et al. (1957) showed that of myofibrils contain two types of threads running in a longitudinal direction: thick, which include myosin, and thin - of actin. Within each of myofibrils beams these threads go for each other. While shortening or stretching the muscles of the two groups of threads slide one relative to another.