96. Hypertrophy of the heart: definition of the concept, classification, causes, stages. Macro- and microscopic changes in the heart during hypertrophy, outcomes, complications, clinical significance.

The causes of cardiac hypertrophy may lie in the pathological processes of the heart itself and in these cases they are called intracardial (intracardiac). In other cases, they may be associated with pathology of the small or large circulatory system, then we are talking about extracardial (extra-cardiac) causes.

Mechanism: - hypertrophy and hyperplasia of the cellular structures of cardiomyocytes (the number of CMC does not increase) due to increased LV load.

1. Hypertrophy of the lv wall.

• Intracardiac causes: Heart defects: aortic stenosis;

• insufficiency of the mitral (bicuspid) valve.

Extracardial causes:

- hypertension and symptomatic (secondary) hypertension.

Macro: the heart is enlarged, the mass is increased, the LV wall is thickened to 2.5 cm. (normally 1.0-1.2 cm).

2. Hypertrophy of the pancreatic wall (pulmonary heart).

Intracardial causes:

• heart defects: stenosis of the mouth of the trunk of the pulmonary artery;

• insufficiency of the pulmonary artery valves;

• tricuspid valve insufficiency;

• stenosis of the left atrioventricular foramen (mitral);

Extracardial causes of hypertrophy of the right ventricle of the heart may be lung diseases, accompanied by a decrease in the volume of the small circle of blood circulation and an increase in blood pressure in the pulmonary artery system:

• chronic diffuse pulmonary emphysema; pneumosclerosis

• chronic obstructive bronchitis;

• primary pulmonary hypertension.

Normally, the wall of the pancreas is 0.2-0.4 cm, reaches 1.0-1.5 cm.

III. “Bull's heart is an enlargement of the whole heart.

- cardiomyopathy (various)

- heart defects

- renal hypertension (sometimes) Outcome: the process is reversible, provided that the cause is eliminated in time. For example, if a patient has timely reconstructive surgery for congenital or acquired heart disease, then heart changes may reverse and return to normal occurs.

Otherwise, there is a relative insufficiency of blood supply, that is, chronic ischemia occurs. Metabolic processes in the hypertrophied heart are disrupted, dystrophic changes occur, and then irreversible changes occur - cell death with the proliferation of connective tissue in their place, that is, decompensation develops.

Meaning. Heart failure develops, which is the cause of death of the patient.

Signs of hypertrophy: an increase in the volume of the heart, the heart muscle on the incision is strongly thickened, full-blooded, thickened muscle fibers clearly protrude, while the heart cavities retain normal volume or are slightly enlarged. Dystrophic processes can often occur in hypertrophied muscle, since the development of blood vessels and nerves lags behind the build-up of muscle mass and the nutritional conditions of hypertrophied muscle fibers are worse than normal. When the causes of cardiac hypertrophy are eliminated, atrophic changes develop in the myocardium with the possible replacement of connective tissue muscle fibers (myofibrosis), and then the expansion of the heart occurs.