Heart failure in children

The term “circulatory failure” is widely used in literature and clinical practice; in fact, it is a circulatory disorder associated with two main factors:

• decreased contractility of the myocardium;
• weakening of the tonic tension of peripheral vessels.

Weakening of the tonic tension of peripheral vessels is, by definition, vascular insufficiency. It is encountered in isolation most often in practically healthy individuals with the phenomena of vegetative dystonia with reduced sympathetic supply and relative predominance of parasympathetic influences, i.e. with asympathicotonia, as well as in individuals with primary true predominance of the parasympathetic influence of the vegetative part of the central nervous system. Of course, vascular insufficiency can be secondary and manifest itself in acute and chronic infections, endocrine pathology, chronic course of non-infectious diseases, including in individuals with cardiovascular pathology.

The leading clinical signs of vascular insufficiency are pallor, possible dizziness, and in extreme situations, loss of consciousness (vaso-vagal syncope) as a result of decreased blood pressure with low peripheral vascular resistance. Vascular insufficiency is not accompanied by dyspnea or tachycardia; liver enlargement is never observed, and there are no peripheral edemas or other signs of congestion. The boundaries of relative cardiac dullness are not expanded, and heart sounds may be louder due to insufficient filling of the heart chambers. In the vascular form of circulatory insufficiency, the contractile function of the heart is not impaired. In individuals with organic cardiac pathology, vascular insufficiency is a consequence of cardiac insufficiency. The combination of vascular and cardiac forms of circulatory insufficiency is called cardiovascular insufficiency.

The concept of heart failure itself can be defined as follows:

• a condition caused by a disturbance of intracardiac and peripheral hemodynamics, associated with a decrease in the contractility of the myocardium;
• a condition caused by the inability of the heart to convert venous inflow into adequate cardiac output.

In fact, the latter definition represents the hemodynamic basis for the clinical signs of heart failure.

There are two forms of heart failure: acute and chronic. Acute heart failure occurs during myocardial infarction, acute mitral or aortic valve failure, or rupture of the left ventricular walls. Acute heart failure can complicate the course of chronic heart failure.

Since we are more often talking about chronic heart failure, we will provide another definition: chronic heart failure is a syndrome that develops as a result of various diseases of the cardiovascular system, leading to a decrease in the pumping function of the heart (although not always), chronic hyperactivation of neurohormonal systems and manifested by shortness of breath, a feeling of palpitations, increased fatigue, limited physical activity and excessive fluid retention in the body.

ICD 10 codes

According to ICD 10, heart failure is classified as class IX: diseases of the circulatory system. It is coded with code 150: congestive heart failure - 150.0, left ventricular - 150.1.

Epidemiology of heart failure

The need to address this problem is dictated by the following reasons:

• poor prognosis of the syndrome;
• the risk of sudden death is 5 times greater than in the population;
• 5-year survival rate of patients with chronic heart failure is less than 50%;
• The number of patients with asymptomatic course (asymptomatic left ventricular dysfunction) significantly exceeds the number of patients with clinically expressed chronic heart failure.

The presented positions concern the adult contingent of patients. There are no exact statistics on the number of patients, and especially children with chronic heart failure in Ukraine.

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.

Causes of Heart Failure

Pathogenesis of heart failure

In this paper, we are talking about chronic heart failure. This is due to the fact that, strictly speaking, acute heart failure without a previous long-term heart disease is not very common in clinical practice. An example of such a condition may probably be acute myocarditis of rheumatic and non-rheumatic genesis. Most often, acute heart failure occurs as a complication of chronic, possibly against the background of some intercurrent disease and is characterized by the rapid development and severity of individual symptoms of heart failure, thereby demonstrating decompensation.

At early stages of cardiac dysfunction or heart failure, peripheral circulation remains adequate to tissue needs. This is facilitated by the activation of primary adaptation mechanisms already at early, preclinical stages of cardiac failure, when there are no obvious complaints yet and only a careful examination allows us to establish the presence of this syndrome.

Pathogenesis of heart failure

Classification of heart failure

Acute and chronic heart failure can be left ventricular and right ventricular, but more often, failure of both ventricles develops simultaneously, i.e. total heart failure. Currently, our country uses two classifications in assessing heart failure in adults.

The classification of N.D. Strazhesko and V.Kh. Vasilenko suggests the following stages.

• Stage I - latent heart failure, revealed only during physical exertion.
• Stage II - severe long-term heart failure (congestion in the small and/or large circulation), symptoms are expressed at rest:
  • II A - hemodynamic disturbances are weakly expressed, in one of the sections (in the large or small circle of blood circulation):
  • II B - profound hemodynamic disturbances - end of a long stage, involvement of the large and small circles of blood circulation:
• Stage III, final - dystrophic changes in organs with severe hemodynamic disturbances, persistent changes in metabolism and irreversible changes in the structure of organs and tissues.

Classification of heart failure

Symptoms of Heart Failure

One of the earliest and most characteristic signs of left ventricular heart failure is shortness of breath. At first, shortness of breath occurs only during physical exertion, fast walking, running, climbing stairs, etc. Later, it occurs at rest, increasing with a change in body position, during conversation and eating. Shortness of breath caused by heart disease increases in the horizontal position of the patient. Therefore, children with heart failure take a forced semi-sitting position (orthopnea), in which they feel relief.

Right ventricular failure is also characterized by subjective symptoms such as rapid fatigue, weakness, sleep disturbances, etc. Cough, shortness of breath, cyanosis are usually expressed to varying degrees and often do not correspond to the severity of congestion in the systemic circulation. They often depend on the nature of the underlying disease underlying the failure of the right sections.

Symptoms of Heart Failure

Diagnostics

The diagnosis of left ventricular failure is also based on the data of instrumental examination methods. Thus, the most informative in this regard are ECG data: the size of the left atrium, left ventricle, and the ejection fraction. In left ventricular failure, these indicators can change significantly. A pronounced increase in the left atrium, as a rule, reflects a high degree of overload of the pulmonary circulation and coincides with the clinical signs of pulmonary hypertension. In some cases, an increase in the left atrium is more important than an increase in the left ventricle.

When assessing the severity of heart failure, one should not forget about general physical examination methods, in particular about blood pressure characteristics. Blood pressure indicators in heart failure can indicate the severity of the patient's condition. Thus, a decrease in cardiac output leads to a decrease in systolic pressure.

Diagnosis of heart failure

Treatment of heart failure

Treatment of heart failure is aimed at increasing the contractility of the myocardium, eliminating congestion (fluid retention), normalizing the functions of internal organs and homeostasis. Of course, a mandatory condition is treatment of the underlying disease that caused heart failure.

General tactics and principles of treatment of chronic heart failure

The goals of treatment for chronic heart failure are:

• elimination of disease symptoms - shortness of breath, palpitations, increased fatigue, fluid retention in the body;
• protection of target organs (heart, kidneys, brain, blood vessels, muscles) from damage:
• improving the quality of life;
• reduction in the number of hospitalizations:
• improving prognosis (extending life).

Treatment of heart failure

Complications of heart failure

Complications may occur at different stages of heart failure. As the degree of heart failure increases, complications occur more frequently and are more severe. Some complications may become the immediate cause of death.

True hyponatremia develops with prolonged use of diuretics against the background of a salt-free diet. In this case, the sodium content in the blood serum is less than 130 mmol/l. There is a painful thirst, loss of appetite, dry mouth, vomiting, etc.

On the ECG, there may be a shortening of the AV conduction and a change in the terminal part of the ventricular complex.

Complications of heart failure

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