Damage to the heart and blood vessels is observed in 50-80% of patients with diabetes, and with its prolonged course – in 100%. They are the main cause of disability and death of patients. The risk of dying from a heart attack or other vascular catastrophe in patients with diabetes is 4-5 times greater than in other people. Myocardial lesions are factors that significantly aggravate the course and prognosis of diabetes. Their origin is complex and due to both hormonal and metabolic disorders inherent in diabetes, and atherosclerotic changes.
In diabetes mellitus, the following main forms of heart disease are distinguished: cardiomyopathy, coronary heart disease and their combination.
In diabetes, against the background of metabolic imbalance, a mismatch develops between the energy supply of the myocardium and its oxygen demand, which intensifies with small loads. This is accompanied by the development of dystrophic changes in the myocardium, which are observed in 48-100% of patients.
Cardiomyopathies are found mainly in patients under the age of 40 years with type I diabetes without microangiopathy and atherosclerosis. Patients complain of palpitations, shortness of breath during physical exertion, pain in the heart. Instrumental studies reveal signs of impaired myocardial contractile function and its degenerative changes, exercise tolerance is preserved or slightly reduced.
In patients younger than 40 years of age, with long-term diabetes, with the presence of generalized microangiopathy, the phenomena of cardiomyopathy are aggravated until the development of subjective and objective symptoms of chronic coronary heart disease. Severe forms of cardiomyopathy under special conditions may be complicated by myocardial necrosis in the absence of organic lesions of the coronary arteries.
Coronary heart disease, atheromatous lesions of the coronary arteries in patients with diabetes are more common, develop at an earlier age, proceed more severely than in the general population, are often combined with hypertension and specific lesions of the vessels of the kidneys, eyes, lower extremities. There is a picture of stenotic coronary sclerosis, microangiopathy and myocardiopathy, which characterizes the term “diabetic heart”. It occurs in middle-aged and elderly people, more often with a prolonged course of non-insulin-dependent diabetes. The clinical symptoms of coronary heart disease do not differ from those in non-diabetic individuals.
However, coronary heart disease in diabetes mellitus is more often than in the general population complicated by myocardial infarction, while the increased risk of developing a heart attack extends to women (even under the age of 40), which is not observed in people without diabetes. Myocardial infarction with diabetes is difficult, with high mortality, often with sudden death. A distinctive feature is the high prevalence of “silent” heart attacks, in which pain is poorly expressed or absent in the acute period. Among the possible causes of the painless course of myocardial infarction indicate generalized capillaropathy, damage to small intramural vessels with impaired function of the neuro-receptor apparatus. Degenerative changes in the small coronary artery, damage to the nerve endings as a result of necrosis and diabetic neuropathy impede the development of collateral circulation, which creates favorable conditions for repeated and widespread heart attacks, the development of aneurysms, and cardiac ruptures. In addition to coronary arteries, atherosclerotic changes are observed in the aorta, cerebral, renal arteries, and lower limb arteries.