According to the localization, the defects of MZhP are divided into: 1. membranous; 2. infundibular (in the outgoing department of the IUP); 3.atrioventricular (defects of the bringing department); 4. muscle. The most frequently diagnosed and hemodynamically significant are defects in the membranous part of the IUP.
EchoCG examination includes visualization of the defect itself in the B-mode, identification of signs of hypertrophy and volume overload of the pancreas in the M-mode, as well as an assessment of the degree of pulmonary hypertension using Doppler research. As a rule, when Doppler studies at the level of the defect in systole (and sometimes in diastole) high-speed flows with a high pressure gradient of 40–90 mm are detected. Hg Art. (the larger the size of the defect – the smaller the pressure gradient) with the directionality of the flow above the zero line. Therefore, hemodynamically insignificant defects of the muscular part are usually high-speed, and with Eisenmenger syndrome, which often complicates large membranous defects, the nature of the discharge becomes low-speed and bidirectional (left-right at the beginning of systole, and right-left at the end)
Color mapping allows you to visualize the defect and the direction of blood flow much faster, and also recognize multiple defects. It should be borne in mind that the size of the diagnosed MZhP detected during the EchoCG examination is usually 20–30% less than the true size.