The systolic function of the LV is estimated by several indicators, the central place among which is occupied by stroke volume (PP), minute volume (MO), ejection fraction (EF) and the rate of circular shortening of myocardial fibers (V cf). TEICHOLZ method. Until recently, the calculation of PP, FV and other hemodynamic parameters was carried out on the basis of measurements in the M-mode when registering the image of the LV in the left parasternal approach. For the calculation, the degree of anteroposterior LV shortening is taken into account, i.e. the ratio of KDR and DAC.The calculation is carried out according to the formula L. Teicholz:
V = 7.0 * D3 / (2, 4 + D), where V is the LV volume (KSO or KDO) and D is the anteroposterior size of the LV in systole or diastole. EO is defined as the difference between BWW and CSR, and EF is defined as the ratio of EO to BWW.
Calculation of the main hemodynamic parameters using the Teicholz method (EDV-end diastolic volume, ESV – end-systolic volume, SV – stroke volume, CO – minute volume, EF-left ventricular ejection fraction).
Currently, most researchers have abandoned this method of determining hemodynamic parameters, since the calculation of LV and CSR LV, according to this method, is based on measuring the CRD and CSR of only a small part of the LV at its base and does not take into account the entire complexity of the ventricular cavity geometry (which is important for patients with violation of local contractility, for example in patients with coronary artery disease). This requires the practitioner to be very careful about the results of measurements and calculations using the Teicholz method. In addition, in some patients, the endocardium of the posterior wall is difficult to locate, and pericardial movements are mistaken for its movements , which leads to an overestimation of the dimensions of the cavities and a decrease in EF values.