The defect includes 4 components: stenosis of the pulmonary artery, ventricular septal defect, destructive aorta, right ventricular hypertrophy.
The most important 2 components of this defect are: stenosis of the pulmonary artery and ventricular septal defect. Pulmonary stenosis can be infundibular, at the level of the valve, pulmonary trunk, or in the subinfibular zone. The combination of valvular and infundibular stenosis is most characteristic. Dextraposition of the aorta can be in varying degrees of severity. Hypertrophy of the right ventricle is secondary and occurs as a result of obstruction of the output tract. The right-sided aortic arch is observed in 20-30%.
One-dimensional echocardiography reveals: aortic dilatation, aortic destraction (location of the anterior aorta wall and interventricular septum at different depths), hypertrophy of the anterior wall of the right ventricle, hypertrophy of the interventricular septum, reduction of the diameter of the pulmonary artery, reduction of the left atrium. A two-dimensional study is characterized by direct visualization of the ventricular septal defect, aortic dislocation and its dilatation in the parasternal projection of the long axis, as well as direct visualization of the stenosis of the pulmonary artery and its localization. Doppler echocardiography reveals turbulent flow in the pulmonary artery stem and the presence of a systolic pressure gradient.
Parasternal position along the long and parasternal position along the short axes Diagram and EchoCG with Fallot’s tetrad.
Open arterial duct
The duct departs from the aorta at the level of the left subclavian artery and flows into the pulmonary artery at the site of its division into two branches. One-dimensional study reveals signs of volume overload of the left heart (an increase in the cavity of the left ventricle and atrium). In a two-dimensional study, direct visualization of the duct from the supraternal access is possible in the form of an echo-free space between the descending aorta and the pulmonary artery. The Doppler-EchoG has the highest sensitivity and specificity in detecting a defect, which allows to detect systolic and diastolic turbulent flows in the pulmonary artery above the valve.