Ischemic heart disease is a group of diseases caused by absolute or relative insufficiency of the coronary circulation.
Risk factors that lead to IHD common factors 1.Men of middle age and older. 2. hyperlipidemia; 3.arterial hypertension; 4.excessive body weight (obesity); 5. a sedentary lifestyle; 6. smoking; 7. violation of tolerance to carbohydrates, in particular diabetes mellitus; 8. genetic predisposition; 9. belonging to the male sex. 10.Women in the period of menopause. 11.neuropsychiatric disorders
local causes of development (Local factors) : prolonged spasm, thrombosis, thromboembolism of coronary arteries of the heart and functional overstrain of the myocardium in conditions of atherosclerotic occlusion of these arteries. Pathogenetic factors of ischemic disease, atherosclerosis and hypertension are also common.
Ischemic myocardial dystrophy, or acute focal dystrophy of the myocardium, develops with relatively short episodes of the coronary crisis, when characteristic changes in the electrocardiogram occur, but there is no enzyme (an increase in the activity of transaminases, lactate dehydrogenase, etc.), which is one proof of the absence of myocardial necrosis.
Macroscopic diagnosis of foci of ischemic dystrophy is possible with the help of tetrazolium salts, potassium tellurite. In areas of ischemia where the activity of oxidation-reduction enzymes is sharply weakened, the formazan grains and the restored tellurium do not fall out, therefore the ischemia sites appear light on the dark background of the unchanged myocardium.
Microscopically find paretic expansion of capillaries, stasis of erythrocytes, edema of interstitial tissue. It is possible to attach to these changes hemorrhages and leukodiapedesis, accumulations of leukocytes along the periphery of the ischemic zone. The muscle fibers lose their striation, are devoid of glycogen, they are intensely stained with eosin, fuchsin, pyronine and Schiff's reagent, which indicates necrobiotic changes.
Complication of myocardial ischemic dystrophy is most often acute heart failure, it also becomes the immediate cause of death. Apparently, therefore, clinicians usually designate this form of coronary heart disease as "acute heart failure."
Myocardial infarction is ischemic necrosis of the cardiac muscle, therefore, clinically, in addition to electrocardiogram changes, it is characterized by enzyme. As a rule, this is an ischemic (white) infarction with a hemorrhagic aureole.
In the necrotic stage in histological investigation, the infarct area is necrotized tissue, in which perivascular "islets" of unchanged myocardium are preserved. The area of necrosis is distinguished from the extant myocardium by the zone of plethora and leukocyte infiltration (demarcation inflammation)
The stage of the scarring (organization) of the infarct begins when essentially the leukocytes are replaced by macrophages and young cells of the fibroblastic series. Macrophages take part in the resorption of necrotic masses, lipids, tissue detritus products appear in their cytoplasm. Fibroblasts, having a high enzymatic activity, participate in fibrillogenesis. The organization of the infarction occurs both from the demarcation zone and from the "islets" of the preserved tissue in the necrosis zone.
Part of the muscle fibers is replaced by a connective tissue (especially noticeably lower left and right on the right). Preserved cardiomyocytes more near the vessels. Among the preserved muscle fibers there are both atrophied and hypertrophied