Heart failure (pediatric)/chronic

Compensatory mechanisms, which include myocardial hypertrophy, activation of the renin-angiotensin-aldosterone system ( RAAS ), are typical for chronic heart failure. There is a decrease in diuresis with retention of sodium and water, and thus an increase in circulating volume. These mechanisms do not have time to apply in acute failure.

According to the type of ventricular dysfunction, we distinguish heart failure:


 * with systolic dysfunction;
 * with diastolic dysfunction.

Systolic dysfunction is the most common. We usually find an enlarged heart with a decrease in contractility, with diastolic dysfunction then usually a non-enlarged heart with impaired diastolic filling. Often, however, systolic dysfunction is associated with diastolic dysfunction. If peripheral symptoms are not expressed during myocardial dysfunction - congestion, swelling, we are talking about compensated heart failure, with decompensated heart failure, there are already clear clinical signs of failure.

Right-sided heart failure
The right ventricular outflow ensures blood flow through the pulmonary circulation. The right chamber performs the function of a volume pump, it tolerates an increase in volume charge more easily than a pressure overload, i.e. work against increased resistance. Right-sided heart failure occurs during pulmonary embolism and in conditions accompanied by significant pulmonary vasoconstriction. Clinical manifestations include tachycardia , cyanosis, hypotension , and typically increased filling of jugular veins, hepatomegaly, peripheral edema .

Left-sided heart failure
The left ventricle of the heart ensures systemic circulation, therefore it has the function of a pressure pump and more easily tolerates work against increased resistance than sudden fluid overload. Left-sided heart failure occurs with hypertension, myocarditis, myocardial ischemia. It causes hypotension and a significant decrease in cardiac output with insufficient tissue perfusion (weak pulsation, cold acra, oliguria). Hypertension represents a chronic pressure overload for the left ventricle. Initially, there is hypertrophy of the ventricle, later complications are ischemic changes and congestive heart insufficiency. More pronounced and longer-lasting insufficiency leads to the development of pulmonary edema(tachypnea, dyspnea) and later also to pulmonaryization of the disorder, i.e. it is associated with right-sided failure and we speak of biventricular failure.

Congestive failure
If the ventricle is unable to expel its contents and the blood accumulates in front of the ventricles in the atria, in the small or large circulation, blood congestion occurs in the pulmonary or systemic circulation. The hemodynamic manifestation of these changes is an increase in pressure in the left atrium and in the pulmonary circulation (wedged pressure in the pulmonary artery) — left ventricular failure and an increase in central venous pressure and pressure in the right atrium — right ventricular failure. The classification into right-sided and left-sided failure is descriptive only. In fact, hemodynamic and neurohumoral changes are present in the entire circulation, and in addition, when one ventricle fails, its dilation and change in the position of the septum worsen the compliance and geometry of the other ventricle, thereby reducing its performance. The term congestive failure refers to a clinical syndrome that is composed of symptoms of congestion and hypoperfusion of organs. Congestion means an increase in the volume of body fluids or their redistribution. Congestive heart failure with normal cardiac output is called compensated, when cardiac output decreases we speak of decompensated failure.

Circulatory heart failure
Circulatory = circulatory failure must be distinguished from "own" heart failure = myocardial dysfunction. Here, symptoms of low minute volume and tissue hypoperfusion occur even with intact myocardial function (e.g. hypovolemia, cardiac tamponade, constrictive pericarditis).

Related Articles

 * Heart failure (pediatrics)/acute

Source

 * HAVRÁNEK, J.: Akutní srdeční selhání.