Acute heart failure in children

Acute heart failure in children is a clinical syndrome characterized by a sudden disruption of systemic blood flow as a result of a decrease in myocardial contractility.

Acute heart failure in children may occur as a complication of infectious-toxic and allergic diseases, acute exogenous poisoning, myocarditis, cardiac arrhythmia, as well as with rapid decompensation of chronic heart failure, usually in children with congenital and acquired heart defects, cardiomyopathy, arterial hypertension. Consequently, acute heart failure may occur in children without chronic heart failure and in children with it (acute decompensation of chronic heart failure).

In acute heart failure, the child's heart does not meet the body's need for blood supply. It develops as a result of decreased contractility of the myocardium or rhythm disorders that prevent the heart from performing its pumping function.

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What causes acute heart failure in children?

• myocardial damage;
• volume and/or pressure overload;
• heart rhythm disturbances.

The leading role in ensuring the adaptive-compensatory reactions of the heart is played by the sympathoadrenal system, the Frank-Starling mechanism, and the renin-angiotensin-aldosterone system.

How does acute heart failure develop in children?

In children under 3 years of age, acute heart failure may be caused by: congenital heart disease, acute infectious diseases manifested by toxic or viral damage to the myocardium, electrolyte disorders. In older children, AHF is usually observed against the background of infectious-allergic carditis, acquired heart defects, poisoning. The classic picture of AHF is formed with pneumonia. There are 3 stages of acute heart failure:

1. The stage is characterized by a decrease in the minute volume of blood, moderate hypervolemia, dyspnea, tachycardia, signs of blood stagnation in the pulmonary or systemic circulation. The ratio of respiratory rate and heart rate increases to 1:3-1:4. The liver enlarges, small wet and dry wheezing can be heard in the lungs, the heart tones are muffled, its borders increase.
2. stage, in addition to the above-mentioned signs, is accompanied by distinct oliguria, obvious peripheral edema, signs of pulmonary edema. RR/HR = 1:4-1:5. CVP increases, jugular veins pulsate, facial puffiness and acrocyanosis appear, the liver enlarges, and moist rales appear in the lungs.
3. stage - hyposystolic phase of acute heart failure with development of arterial hypotension against the background of pulmonary edema and (or) peripheral edema in combination with severe intravascular hypovolemia (decrease in circulating blood volume). Characterized by a decrease in blood pressure and an increase in central venous pressure. Distinct oliguria.

According to the pathogenetic mechanism, energetic-dynamic and hemodynamic forms of AHF are distinguished. In the first case, the basis of acute heart failure is the depression of metabolism in the myocardium, in the second - the suppression of the heart due to its long-term work to overcome high vascular resistance (for example, with stenosis of the aorta or the mouth of the right ventricle).

Pathogenetic forms of acute heart failure

• The energetic-dynamic form arises as a result of primary disturbances in metabolic and energetic processes in the myocardium (myocardial insufficiency due to damage, or asthenic form, according to A.L. Myasnikov).
• Hemodynamic form. Acute heart failure in children is caused by overload and secondary metabolic disorders against the background of hypertrophy (myocardial insufficiency due to overstrain, or hypertensive form, according to A.L. Myasnikov).

When assessing acute heart failure, it is advisable to distinguish its clinical variants.

Clinical variants of acute heart failure:

• left ventricular;
• right ventricular;
• total.

Hemodynamic variants of acute heart failure:

• systolic:
• diastolic;
• mixed.

Degrees of insufficiency: I, II, III and IV.

Symptoms of Acute Heart Failure in Children

The main clinical signs of acute heart failure are: dyspnea, tachycardia, dilation of the heart borders due to dilation of the heart cavities or myocardial hypertrophy, enlargement of the liver, especially the left lobe, peripheral edema, and increased central venous pressure. EchoCG data reveals a decrease in the ejection fraction, and chest X-ray data reveals congestion in the lungs.

Acute left ventricular failure

Clinically, it manifests itself with symptoms of cardiac asthma (interstitial stage of pulmonary edema) and pulmonary edema (alveolar stage of pulmonary edema). An attack of cardiac asthma begins suddenly, often in the early morning hours. During an attack, the child is restless, complains of shortness of breath, tightness in the chest, fear of death. Frequent, painful cough with the release of scanty light sputum, dyspnea of a mixed type occur. Orthopnea is typical. During auscultation, harsh breathing with an extended exhalation is heard. Moist rales may not be heard at first, or a scanty amount of fine-bubble rales over the lower parts of the lungs is determined.

Pulmonary edema manifests itself as severe dyspnea of inspiratory or mixed type. Breathing is noisy, bubbling: cough is wet, with the release of foamy sputum, usually colored pink. Symptoms of acute hypoxia (pallor, acrocyanosis), agitation, fear of death, and consciousness is often impaired.

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Acute right ventricular failure

Acute right ventricular failure is the result of a sharp overload of the right sections of the heart. It occurs with thromboembolism of the pulmonary artery trunk and its branches, congenital heart defects (pulmonary artery stenosis, Ebstein's anomaly, etc.), a severe attack of bronchial asthma, etc.

It develops suddenly: a feeling of suffocation, tightness behind the breastbone, pain in the heart area, and severe weakness immediately appear. Cyanosis quickly increases, the skin becomes covered in cold sweat, signs of increased central venous pressure and congestion in the systemic circulation appear or intensify: the jugular veins swell, the liver quickly enlarges and becomes painful. The pulse is weak and becomes much more frequent. Blood pressure is reduced. Edema may appear in the lower parts of the body (with prolonged horizontal position - on the back or on the side). Clinically, it differs from chronic right ventricular failure by intense pain in the liver area, which intensifies with palpation. Signs of dilation and overload of the right heart are determined (expansion of the borders of the heart to the right, systolic murmur over the xiphoid process and protodiastolic gallop rhythm, accentuation of the second tone on the pulmonary artery and corresponding ECG changes). A decrease in left ventricular filling pressure due to right ventricular failure can lead to a drop in the minute volume of the left ventricle and the development of arterial hypotension, up to the picture of cardiogenic shock.

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Total acute heart failure in children

It occurs mainly in young children. It is characterized by signs of congestion in the large and small circle of blood circulation (shortness of breath, tachycardia, liver enlargement, swelling of the jugular veins, fine bubbling and crepitating rales in the lungs, peripheral edema), muffled heart sounds, and decreased systemic arterial pressure.

Cardiogenic shock

In children, it occurs with a rapid increase in left ventricular failure. against the background of life-threatening arrhythmias, destruction of heart valves, cardiac tamponade, pulmonary embolism, acute myocarditis, acute dystrophy or myocardial infarction. In this case, cardiac output and BCC decrease sharply with a decrease in arterial and pulse pressure. The hands and feet are cold, the skin pattern is "marbled", the "white spot" when pressing on the nail bed or the center of the palm disappears slowly. In addition, as a rule, oliguria occurs, consciousness is impaired, CVP is reduced.

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Treatment of acute heart failure in children

Treatment of acute heart failure in children is carried out taking into account clinical and laboratory data, the results of additional research methods. It is very important to determine the form, variant and degree of its severity, which will allow the best possible implementation of therapeutic measures.

In severe acute heart failure, it is very important to elevate the child and ensure rest. Nutrition should not be abundant. It is necessary to limit the intake of table salt, liquids, spicy and fried foods, foods that promote flatulence, as well as stimulating drinks (strong tea, coffee). It is best to give expressed breast milk to infants. In some cases of severe heart failure, it is advisable to carry out parenteral nutrition or tube feeding.

The main principles of treating acute heart failure in children are the use of cardiac glycosides (usually digoxin for parenteral administration), diuretics (usually lasix at a dose of 0.5-1.0 mg / kg) to unload the pulmonary circulation, cardiotrophic drugs (potassium preparations) and drugs that improve coronary and peripheral blood flow (complamin, trental, agapurin, etc.). The sequence of their use depends on the stage of AHF. Thus, at stage I, the main attention is paid to improving microcirculation, cardiotrophic therapy, including aerotherapy. At stage II, treatment begins with oxygen therapy, diuretics, drugs that improve myocardial trophism; then glycosides are used at a moderately rapid saturation rate (in 24-36 hours). At stage III of acute heart failure, therapy often begins with the administration of cardiotonics (for example, dobutrex at a dose of 3-5 mcg/kg per minute), the administration of cardiac glycosides, diuretics, cardiotrophic agents, and only after hemodynamic stabilization are microcirculators connected.

In case of prevalence of cardiac asthma in the clinic (overload of the left heart chambers), the following measures should be taken:

• the child's head and upper shoulder girdle are given an elevated position in the bed;
• inhalation of oxygen at a concentration of 30-40%, supplied through a face mask or nasal catheter;
• administration of diuretics: lasix at a dose of 2-3 mg/kg orally, intramuscularly or intravenously and (or) veroshpiron (aldactone) at a dose of 2.5-5.0 mg/kg orally in 2-3 doses under the control of diuresis;
• In case of tachycardia, cardiac glycosides are indicated - strophanthin (at a dose of 0.007-0.01 mg/kg) or corglycon (0.01 mg/kg), repeated every 6-8 hours until the effect is achieved, then in the same dose after 12 hours, digoxin at a saturation dose (0.03-0.05 mg/kg) in 4-6 doses intravenously after 6-8 hours, then at a maintenance dose (75 of the saturation dose), divided into 2 parts and administered after 12 hours. An option for accelerated dosing of digoxin is also proposed: 1/2 the dose intravenously immediately, then 1/2 the dose after 6 hours; after 8-12 hours, the patient is transferred to maintenance doses: 1/2 the saturation dose in 2 doses after 12 hours.
• cardiotrophic therapy: panangin, asparkam or other potassium and magnesium preparations in age-appropriate doses.

When alveolar pulmonary edema manifests, the following treatment is added:

• inhalation of 30% alcohol solution for 20 minutes to reduce foaming of sputum; 2-3 ml of 10% solution of antifoamsilane in children over 3 years old;
• oxygen therapy up to 40-60% 02 and, if necessary, mechanical ventilation with airway clearance by suction (very carefully due to possible reflex cardiac arrest), the PEEP mode can worsen hemodynamics;
• It is possible to prescribe ganglionic blockers (pentamine) in complex therapy for pulmonary edema, with known hypertonicity of the pulmonary vessels and increased central venous pressure and blood pressure;
• prednisolone at a dose of 1-2 mg/kg orally or 3-5 mg/kg intravenously, especially in the development of acute heart failure against the background of infectious-allergic carditis; the course of treatment is 10-14 days with gradual withdrawal;
• The administration of analgesics (promedol) and sedatives is indicated.

Emergency care for acute left ventricular failure

If there are signs of cardiac asthma and pulmonary edema, the child is placed in an elevated position with legs down, the airways are kept clear, and oxygen passed through 30% ethanol is inhaled for 15-20 minutes, alternating it with 15-minute inhalations of humidified oxygen.

Children of all ages should be given furosemide at a dose of 1-3 mg/kg intravenously by bolus, the maximum dose is 6 mg/kg. In order to reduce pre- and post-load, veno- and vasodilators (nitroglycerin at a rate of 0.1-0.7 mcg/kg x min), sodium nitroprusside at a dose of 0.5-1 mcg/kg x min) are administered intravenously by drip.

Persistent signs of pulmonary edema with stabilization of hemodynamics may indicate an increase in membrane permeability, which dictates the need to add glucocorticosteroids to the complex therapy (hydrocortisone at the rate of 2.5-5 mg / kg x day, prednisolone - 2-3 mg / kg x day) intravenously or intramuscularly). To reduce the increased excitability of the respiratory center, children over 2 years old are shown the introduction of a 1% morphine solution (0.05-0.1 mg / kg) or 1% solution, and in order to increase tolerance to hypoxia, a 20% sodium oxybate solution is administered intravenously at 50-70 mg / kg. In the presence of bronchospasm and bradycardia, it is advisable to administer intravenously a 2.4% aminophylline solution at a dose of 3-7 mg / kg in 10-15 ml of a 20% dextrose solution. Aminophylline is contraindicated in coronary insufficiency and myocardial electrical instability.

Modern methods of drug treatment have reduced the importance of applying venous tourniquets to the extremities to a minimum, however, if adequate drug therapy is impossible, this method of hemodynamic unloading not only can, but should be used, especially in rapidly progressing pulmonary edema. Tourniquets are applied to 2-3 extremities (upper third of the shoulder or thigh) for 15-20 minutes, with the procedure repeated after 20-30 minutes. An indispensable condition is maintaining the pulse in the artery distal to the tourniquet.

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Hypokinetic variant of acute left ventricular failure

In order to increase the contractility of the myocardium, fast-acting drugs with a short half-life (sympathomimetics) are used. Of these, dobutamine [2-5 mcg/kg x min] and dopamine [3-10 mcg/kg x min] are most often used. In decompensated heart failure, cardiac glycosides are prescribed (strophanthin at a dose of 0.01 mg/kg or digoxin at a dose of 0.025 mg/kg intravenously slowly or by drip). The use of cardiac glycosides is most justified in children with tachystolic atrial fibrillation or flutter.

Hyperkinetic variant of acute left ventricular failure

Against the background of normal or elevated blood pressure, ganglionic blockers should be administered (azamethonium bromide at a dose of 2-3 mg/kg, hexamethonium benzosulfonate - 1-2 mg/kg, arfonad - 2-3 mg/kg). They promote the redistribution of blood from the pulmonary circulation to the systemic circulation ("bloodless bloodletting"). They are administered intravenously by drip under the control of blood pressure, which should decrease by no more than 20-25%. In addition, with this option, the administration of a 0.25% solution of droperidol (0.1-0.25 mg/kg) intravenously is indicated, as well as nitroglycerin, sodium nitroprusside.

Emergency care for acute right ventricular and total heart failure

First of all, it is necessary to eliminate the causes of heart failure and begin oxygen therapy.

To increase the contractility of the myocardium, sympathomimetics (dopamine, dobutamine) are prescribed. Until now, cardiac glycosides have been used [digoxin is prescribed for the hemodynamic form of heart failure in a saturation dose of 0.03-0.05 mg/kg/day]. The maintenance dose is 20% of the saturation dose. In conditions of hypoxia, acidosis and hypercapnia, cardiac glycosides should not be prescribed. They should also not be used in case of volume overload and diastolic heart failure.

The prescription of vasodilators depends on the pathogenetic mechanisms of hemodynamic disorders. To reduce preload, venous dilators (nitroglycerin) are indicated, and to reduce afterload, arterial dilators (hydralazine, sodium nitroprusside) are indicated.

In the complex therapy of the indicated types of heart failure, it is necessary to include cardiotrophic drugs; in the presence of edema syndrome, diuretics (furosemide) are prescribed.

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Emergency care for cardiogenic shock

A child with cardiogenic shock should be in a horizontal position with legs raised at an angle of 15-20°. In order to increase the BCC and increase arterial pressure, infusion therapy should be performed. Usually, rheopolyglucin is used for this purpose at a dose of 5-8 ml/kg + 10% glucose solution and 0.9% sodium chloride solution at a dose of 50 ml/kg in a ratio of 2 to 1 with the addition of cocarboxylase and 7.5% potassium chloride solution at a dose of 2 mmol/kg of body weight, 10% dextrose solution.

If low blood pressure persists, glucocorticosteroids and sympathomimetics (dopamine, dobutamine) are prescribed. In cardiogenic shock with moderate arterial hypotension, dobutamine is preferable, and in severe arterial hypotension, dopamine. When used simultaneously, a more pronounced increase in blood pressure is achieved. With increasing arterial hypotension, dopamine is best used in combination with norepinephrine, which, having a predominantly alpha-adrenergic stimulating effect, causes narrowing of peripheral arteries and veins (while the coronary and cerebral arteries dilate). Norepinephrine, promoting the centralization of blood circulation, increases the load on the myocardium, worsens the blood supply to the kidneys, and promotes the development of metabolic acidosis. In this regard, when using it, blood pressure should be increased only to the lower limit of the norm.

In children with diastolic defect syndrome, developing against the background of severe tachycardia, magnesium preparations should be administered (potassium and magnesium aspartate at a dose of 0.2-0.4 ml/kg intravenously).

In order to reduce the need for oxygen and provide a sedative effect, it is recommended to use GABA (in the form of a 20% solution of 70-100 mg/kg), droperidol (0.25 mg/kg) intravenously.

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