Causes of heart failure

In terms of age, the etiological factors of heart failure may be the following:

• neonatal period: congenital heart defects, as a rule, at this age are complex, combined and combined;
• infancy:
  • congenital heart defects, congenital myocarditis - early (endocardial and myocardial fibroelastosis) and late;
  • acquired valvular heart defects, at this age - as a consequence of infective endocarditis;
  • acute myocarditis.

Congenital heart defects are probably the most common cause of heart failure at any age. However, at a certain age stage, other causes of heart failure are also identified. Thus, from the age of 7 (very rarely earlier), the formation of valvular heart defects of rheumatic genesis is possible, as well as the formation of rheumatic carditis with predominant damage to the myocardium, much less often - the formation of rheumatic pancarditis.

Cardiomyoptia - dilated (congestive) and hypertrophic - manifest clinically, manifestly at any age.

Uncommon causes of heart failure include conditions defined as arrhythmogenic heart failure, which arise as a result of excessive exploitation of the myocardial capacity, such as in some forms of chronic tachyarrhythmias.

Extracardiac causes of heart failure are kidney diseases with oliguria and anuria, bronchopulmonary pathology - hyaline membrane syndrome in newborns, acute and chronic pneumonia, fibrosing alveolitis (Hamman-Rich syndrome), injuries. Unfortunately, clinical situations of iatrogenic heart failure are encountered, most often - with inadequate infusion therapy. In clinical practice, we had to deal with situations when infusion therapy was prescribed already with heart failure, in particular against the background of ongoing acute myocarditis, "for the purpose of detoxification." Of course, such treatment tactics lead, at best, to an increase in the severity of the patient's condition.

In some extracardiac conditions (hyperthyroidism, severe forms of anemia, liver cirrhosis, arteriovenous fistulas), an increase in cardiac output is observed, and circulatory disorders occur due to the fact that the pumping function of the heart is unable to meet the increased needs of the body.

Taking into account the etiological factors leading to damage to the heart muscle, the following forms of heart failure can be distinguished.

• The myocardial-metabolic form, or heart failure due to damage, occurs in diseases of the heart muscle of a toxic, infectious and allergic nature, i.e. this form is caused by primary damage to the heart muscle without its previous hypertrophy.
• Heart failure from overload is a condition in which the contractility of the myocardium decreases as a result of overfatigue and secondary changes based on hyperfunction. Such changes most often accompany heart defects, as well as conditions of increased pressure in the small and large circles of blood circulation.
• A mixed form of heart failure, in which factors of damage and overload of the heart are combined, for example, in thyrotoxicosis and rheumatic heart defects.

There are also systolic and diastolic forms of heart failure.

• In the systolic form, the decrease in cardiac output is caused by a decrease in the contractility of the myocardium or volume overload.
• The diastolic form is caused by a decrease in the filling of the heart cavities (ventricles) during diastole; most often, this situation occurs when there is a disturbance in the relaxation of the myocardium during the diastole phase, which is possible with hypertrophic, obstructive cardiomyopathy, constrictive pericarditis, a decrease in the volume of the cavities due to tumors, or with tachystolic forms of rhythm disturbance, when diastole is shortened.

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