Myocardium dystrophy - the diseases of a myocardium of noninflammatory and nekoronarogenny genesis arising owing to disturbances of its metabolism (a metabolism and power) and resulting in insufficiency sokratitelny and other its functions.
Classification of dystrophies of a myocardium
On a current: acute, subacute, chronic and from the outcome in a miodistrofichesky cardiosclerosis.
On prevalence of pathological process: focal and diffusion.
Pathogeny of dystrophies of a myocardium
On a pathogeny allocate potassium dystrophies of a myocardium, katekholaminovy dystrophies of a myocardium, a membranopathy and fermentopatiya.
Mainly potassium dystrophies of a myocardium are observed at endocrine diseases (a diabetes mellitus, a hypercorticoidism, chronic insufficiency of bark of adrenal glands), at acute and persistent infections, a renal failure. In a pathogeny of potassium dystrophy of a myocardium matters not only change of a gradient inside - and extracellular potassium at normally functioning potassium channels of a membrane, but also defeat of a membrane with dysfunction of potassium channels at a normal gradient inside - and extracellular potassium. In hard cases also fermental systems of cationic transport can be broken that reduces potassium concentration in a cell.
At mainly katekholaminovy dystrophies of a myocardium which arise at a stress, a climax, a hyperthyroidism, a pheochromocytoma, under the influence of catecholamines membranes of cardiomyocytes are surprised, peroxide oxidation of lipids in membranes of cells becomes more active, membranes of sarcolemmas and a sarcoplasmic reticulum, and also fermental systems of cationic transport are damaged (Sa2+, Mg2+, Na2+, To +-dependent Atfaza). Damage of membranes leads to increase in concentration of calcium in cardiomyocytes that reduces diastolic relaxation of a myocardium. Besides, activity calcium - dependent proteases which destroy some structures of myofibrils and mitochondrions increases. The centers of necroses with the subsequent development of a miodistrofichesky cardiosclerosis and decrease in sokratitelny function of a myocardium are formed.
Clinical displays of dystrophy of a myocardium
Clinical displays of dystrophy of a myocardium can be various, depend on character of a basic disease, prevalence of damage of a myocardium, disease duration.
Long time a disease can proceed latentno, but cases of sudden death at an acute physical overstrain at athletes are known. At the same time morphologically reveal development of contractures of cardiomyocytes due to excess accumulation of calcium ions. At an initial stage of dystrophy of a myocardium clinical manifestations can be minimum and only at functional researches of heart (an ECG, EhoKG, etc.) damage of a myocardium is confirmed. The most frequent displays of dystrophy of a myocardium are cardialgias, symptoms of heart failure, disturbance of a cordial rhythm and conductivity.
Pains in precardiac area often have the aching or pricking character, have no accurate communication with an exercise stress, but quite often amplify after long physical or psychoemotional tension. Precursory symptoms of decrease in sokratitelny function of a myocardium are tachycardia, fast fatigue, weakness, especially at exercise stresses. At the beginning of a disease an asthma arises only at considerable loadings; when progressing dystrophy of a myocardium it develops at the minimum loadings, quite often passing into asthma (cardiac asthma). Total heart failure with the stagnation phenomena in a small and big circle of blood circulation, emergence of a hydrothorax, ascites, a hydrocardia develops in far come stage of a disease.
The most frequent disturbances of a heart rhythm at dystrophy of a myocardium are sinus tachycardia, an ikstrasistoliya. the sinus bradycardia is possible, the ciliary arrhythmia quite often comes to light, also disturbances of atrioventricular conductivity and intra ventricular blockade are observed.
First of all, it is necessary to treat the basic disease which caused myocardium dystrophy, to carry out correction of electrolytic disturbances. At dystrophy of a myocardium of katekholaminovy genesis appoint beta adrenoblockers (propraiolol, atenolol, etc.). The drugs improving metabolic processes in a myocardium (inosine, Mildronate, neotone, vitamins) are widely used. The symptomatic treatment includes purpose of antiaritmik and drugs for treatment of heart failure.