The concept of hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy - a diseasecharacterized by independent, not dependent on other diseases of the cardiovascular system significantly thickened (hypertrophy) of the ventricles with a simultaneous decrease of the internal volume. In the case of myocardial hypertrophy prevents normal outflow of blood from the ventricles of the heart, it obstruktivnoaya form of hypertrophic cardiomyopathy. In all other cases, non-obstructive hypertrophic cardiomyopathy is considered. In the majority of cases there is left ventricular failure.
The causes of the disease
The disease can be congenital or acquired. Congenital hypertrophic cardiomyopathy is inherited and often runs in families. Causes of acquired hypertrophic cardiomyopathy is not completely clear. According to one hypothesis, patients with acquired hypertrophic cardiomyopathy during the prenatal period of life formed the so-called defect of adrenergic cardiac receptors, which carry out the regulation of cardiac activity, such as heart rate. In the blood of any person constantly circulating norepinephrine and other quickens the heart rate naturally occurring chemicals (hormones). In persons with defective receptors significantly increased sensitivity to noradrenaline and similar hormones that contribute to their development of myocardial hypertrophy and eventually hypertrophic cardiomyopathy.
Basic mechanisms of the development of hypertrophic cardiomyopathy
Due to severe myocardial hypertrophy wallventricle disturbed normal ventricular filling with blood. As a result, the ventricle comes less than in healthy individuals, the amount of blood. At the same time expressed myocardial stiffness causes a persistent increase in intraventricular pressure. And the expression of myocardial stiffness, and increased intraventricular pressure lead to the fact that a smaller amount of blood ejected from the ventricle when the heart beats. At the beginning of the disease, these changes did not manifest itself. Gradually, beginning with the major, and then with less physical activity, the disease manifests itself.
Normally, for the release of all loadsblood from the heart must increase the need for adequate oxygen delivery to organs and tissues of the body. To do this, when the load increases the heart rate. In hypertrophic cardiomyopathy heart filled with blood and suffering alone, and during the load it further deteriorates due to an increase in heart rate. Thus, adequate growth of cardiac pump function during execution of the load occurs. Physical activity in hypertrophic cardiomyopathy also leads to a significant increase in intraventricular pressure, which in turn causes an increase in upstream pressure in the left atrium and the small vessels (pulmonary) circulation. As a result of all these changes, there is shortness of breath, increasing in proportion to the degree of the load. Because during exercise ejection of blood from the left ventricle is not adequate increase in load, one of the first begins to suffer blood flow in the coronary arteries supplying the heart muscle itself.
Furthermore, in hypertrophic cardiomyopathythere is always a discrepancy between the capabilities of the coronary blood supply, remain the same as in healthy people, and a large mass of myocardium. The decrease in the coronary arteries appears angina blood - typical pain attack in the middle and on the left side of the chest. As well as shortness of breath, angina triggered by stress and goes alone. In some cases, stress also deteriorates the brain blood flow, which is manifested syncope. It should be noted that for some time to overcome the increase in intraventricular pressure during loading, "connected" compensatory mechanism following: left atrial cavity expands and its wall thickness increases. Such changes further promote the blood filling the left ventricle during exercise. But due to the fact that the allowance of the left atrium as a "pump" light, shortly refuses and this additional mechanism. A significant expansion of the left atrium predisposes to the development of atrial fibrillation. In addition to atrial fibrillation in most cases characterized by hypertrophic cardiomyopathy and a variety of other heart rhythm disorders (arrhythmias), which often are life threatening in nature. Arrhythmias often provoked by emotional or physical stress and may be accompanied by faintness, and sometimes lead to sudden death. At the heart cavities due to their reduced distensibility may form clots. Distribution of fragments of blood clots from the bloodstream (embolism) can cause heart attacks internal organs and occlusion of large vessels.
Symptoms of the disease
Availability and time (timing) of complaints whenhypertrophic cardiomyopathy is mainly determined by two factors: some of the ventricles of the heart is changed as a result of the disease. Hypertrophy of the left ventricle, which is the most powerful chamber of the heart, can remain unnoticed for years and decades. Only when the left ventricle begins to "donate" their positions, there will be complaints. Isolated right ventricular failure is extremely rare (most often marked hypertrophy of the interventricular septum - a common wall of both ventricles). gipetroficheskoy cardiomyopathy, when the outflow of blood from the ventricle does not interfere with the obstructive form of the complaints generally can not be. Sometimes there may be a shortness of breath (when the significant physical exertion), disruption of the heart and irregular heartbeat. The presence of obstruction (obstacle) the outflow of blood from the ventricle significantly reduces the emission of blood from the heart during exercise. When gipertroyicheskoy cardiomyopathy obstructive form of the typical complaints are: shortness of breath during exercise, angina and syncope. The emergence of complaints in patients with obstructive form is the reason of their visit to a doctor. Complaints with hypertrophic cardiomyopathy since its launch are progressing slowly, which is a characteristic feature of the disease.