Myocardial dystrophy - a noninflammatory lesion of a cardiac musle as a result of disturbances of its metabolism under influence of extracardiac factors.

Etiology. Acute and chronic exogenous intoxications, including alcoholic, endocrine and metabolic disturbances (a thyrotoxicosis, a myxedema, an obesity, a diabetes mellitis, avitaminoses, starvation) anemias, a pathological climacterium, a physical overstrain (« soldier's heart »), infections (including tonsillar), physical agents (radiation, weightlessness, an overheating), general diseases (diffusive diseases of a connecting tissue, a muscular dystrophia, etc.). To myocardial dystrophies carry also adjournment in a myocardium of pathological products of an exchange or normal metabolites: an amyloid, iron (at a hemochromatosis), a glycogen, etc. Some forms of a myocardial dystrophy quite often name also myocardiopathies (alcoholic, climacteric, amyloid).

Pathogenesis. Change of current of biochemical processes in a myocardium with the subsequent disturbance of microstructures and functions of muscular fibers. Signs quite often mask displays of a basic disease. Undue fatiguability, a small dyspnea is marked at physical strains.