Pediatric cardiology: diseases — симптомы, диагностика и лечение

Long QT syndrome is a condition in which the heart muscle takes too long to recover between contractions. This is visible on the electrocardiogram as prolongation of the QT interval. The danger is that at such a vulnerable moment a special type of ventricular tachycardia can start, causing fainting, and in severe cases, cardiac arrest. The syndrome can be congenital, associated with changes in ion channel genes, or acquired, most often due to taking drugs that prolong QT, or potassium and magnesium deficiency. Typical situations when fainting occurs are physical activity, sudden fear, loud sound, and in some patients, sleep. The condition is well controlled with proper management.

Sinus arrhythmia is an irregular heart rhythm in which the impulses still originate from the sinus node, but the intervals between beats are slightly different. Most often this is a respiratory arrhythmia: when you inhale, the pulse quickens, when you exhale it slows down. This fluctuation reflects the normal influence of the autonomic nervous system on the heart and is especially pronounced in children, adolescents and young adults. Therefore, the entry “sinus arrhythmia” in the ECG conclusion of a child without complaints usually does not mean illness. Less common is non-respiratory sinus arrhythmia, which occurs in the elderly, with heart disease or taking certain medications. An examination is needed if the irregular rhythm is combined with fainting, shortness of breath, chest pain or severe weakness.

Pulmonary stenosis is a congenital narrowing of the pathway through which blood from the right ventricle enters the lungs. Most often, the valve itself is narrowed: its flaps are fused and do not open completely. To push blood through a narrow opening, the right ventricle works with increased pressure, its wall thickens, and with prolonged overload, the pumping function begins to suffer. Mild forms are common, do not manifest themselves in any way and are detected by a heart murmur. Severe narrowing in newborns can lead to cyanosis and requires treatment in the first days of life. The main diagnostic method is echocardiography.

Tetralogy of Fallot is the most common congenital heart defect accompanied by cyanosis. It has four components: narrowing of the right ventricular outlet, a large ventricular septal defect, displacement of the aorta that lies above the defect, and thickening of the right ventricular wall. Due to the obstruction on the way to the lungs, part of the venous blood enters through the defect directly into the aorta and spreads throughout the body, bypassing the lungs - the skin acquires a bluish tint. The severity depends on the degree of narrowing. The defect is recognized in the first months of life, and sometimes even before birth, and treated surgically.