EchoCG is performed from the following standard sensor positions: 1. Parasternal access – region 3 – 4 intercostal spaces to the left of the sternum
2. Apical (apical) – apical impulse zone
3. Subkostal – from the xiphoid process
4. Suprasternal – jugular fossa
In some standard positions of the sensor, ultrasound examination of the heart is carried out in several directions: along the long and short axis of the organ (as a rule, it is parasternal and subkostal). Since B mode gives the most complete picture of the structural and geometric features of the organ under study, the study usually begins with it. Below are the schematic images of the heart and its structures in B – mode in the study of the main approaches.
Systole (valves open), diastole (valves closed).
Parasternal access on the short axis at the level of the aortic valves.
Research in the M -mode is often carried out from the left parasternal access along the long axis of the heart. The angle of inclination of the sensor is chosen so that the ultrasound beam “cuts through” the heart at the level of the aorta, the cusps of the mitral valve, and also the LV cavity at the level of the tendon filaments. In these positions, a quantitative and qualitative assessment of the studied structures is carried out. At the level of the aortic section: aortic diameter, aortic valve opening degree, size of the left atrium. At the level of the mitral valve: an assessment of its structure and nature of movement. Normally, diastole is determined by a two-phase M-shaped movement of the anterior and W-shaped movement of the posterior cusps (Fig.1.10). On the curve of movement of the front flap there are several sections with the letter designation:
The CD interval corresponds to the LV systole and complete closing of the valves. The DE interval reflects the divergence of the valves in the fast filling phase. Interval EF incomplete valve cover in the slow filling phase. Wave A is caused by repeated divergence of the valves into the atrial systole phase.
At the level of tendon filaments, a measurement is made of the systolic-diastolic size of the LV cavity, the thickness of the IVS and CS in the diastole, their excursion, as well as the size of the RV cavity and the thickness of its wall.
The absolute values of the parameters under study, and their indices (IKDRlzh – index of the end-diastolic size of the LV, IKSRlzh-index of the end-systolic size of the LV, ITMZhP – index of the thickness of the interventricular septum, etc.). Dubois tables are used to calculate indexed indicators. This is essential in the diagnosis of myocarditis, small hypertrophies, etc.