What does vice consist of?
The four components of the tetrad are formed from one developmental disorder - a displacement of the septum in the outflow tract of the heart. A narrowing of the path from the right ventricle to the pulmonary artery occurs, a large ventricular septal defect remains underneath, the aorta shifts to the right and appears above the defect, receiving blood from both ventricles, and the right ventricular muscle thickens due to constant overload. The stronger the narrowing of the outlet section, the more venous blood is discharged into the aorta and the more pronounced the cyanosis.
- Right ventricular outflow stenosis
- Ventricular septal defect
- Dextraposition of the aorta over the defect
- Right ventricular hypertrophy
- The degree of cyanosis depends on the severity of the stenosis
- Possible combinations with other vascular anomalies
Causes and risk factors
The defect occurs in the first weeks of pregnancy, and the exact cause usually cannot be determined. It is known that the likelihood increases with some chromosomal and genetic syndromes, in particular with microdeletion of the twenty-second chromosome and with Down syndrome. Poorly controlled diabetes in the mother, infections suffered in the first trimester, taking a number of medications, and alcohol are important. The risk is higher if congenital heart defects already exist in the family, so fetal echocardiography is recommended for such women.
- Genetic and chromosomal syndromes
- Poorly controlled maternal diabetes
- Infections in the first trimester of pregnancy
- Alcohol and certain medications during pregnancy
- Congenital heart defects in relatives
- Fetal echocardiography for risk factors
Symptoms and cyanotic attacks
The main symptom is cyanosis of the skin, lips and nail beds, which intensifies with crying, feeding, and straining. Children with moderate stenosis may not have blueness at rest for the first months. A typical manifestation is dyspnea-cyanotic attacks: the child suddenly becomes restless, breathing quickens, cyanosis increases sharply, and possible limpness and loss of consciousness. Older children instinctively squat down, which reduces blood flow and alleviates the condition. Over time, thickening of the terminal phalanges and a lag in physical development appear.
- Blueness of lips, nails, skin
- Increased cyanosis with crying and feeding
- Dyspnea-cyanotic attacks
- Squatting pose for older children
- Rough heart murmur
- Thickening of the fingertips
- Lag in weight and height
Diagnostics
Often the defect is detected before birth by fetal echocardiography. After birth, it is indicated by cyanosis and reduced blood oxygen saturation on pulse oximetry, as well as a rough noise when auscultated. The diagnosis is confirmed by echocardiography: it shows all four components, the degree of narrowing and the structure of the pulmonary arteries. An ECG reveals an overload of the right sections, an x-ray reveals a characteristic form of a cardiac shadow. Before surgery, a contrast-enhanced CT scan or cardiac catheterization may be needed to clarify the vascular anatomy.
- Echocardiography of the fetus during pregnancy
- Pulse oximetry of a newborn
- EchoCG as the main method
- ECG
- Chest X-ray
- CT angiography or catheterization before surgery
- Genetic testing for suspected syndrome
Treatment and life after surgery
Treatment is surgical. Radical correction is usually performed in the first year of life: the septal defect is closed with a patch and the outlet of the right ventricle is widened. If the child is too small or the vascular anatomy is unfavorable, a palliative operation is first performed - a shunt is placed to improve blood flow in the lungs, and radical correction is carried out later. In case of a cyanotic attack, before the doctors arrive, the child is calmed down and the knees are brought to the chest, calling an ambulance by number 103. After the operation, children are observed for life: pulmonary valve insufficiency and arrhythmias are possible.
- Radical correction of the defect in the first year of life
- Palliative bypass surgery for unfavorable anatomy
- Emergency care for a cyanotic attack
- Pose with knees brought to the chest during an attack
- Prevention of infective endocarditis
- Lifelong observation by a cardiologist with echocardiography
- Possible pulmonary valve replacement in the future
