1. Recording of ECG & RHEO of ascending aorta in practice: use of an original single-lead system including placement of an electrode on the anterior median line within the heart apex area.
Fig. 1 Scheme of electrode arrangement for recording ECG & RHEO of ascending aorta
2. Analysis: cardiac cycle phase structure
Fig. 2. Cardiac cycle phase structure according to ECG & RHEO
3. ECG first derivative curve: tool No.1 for identifying each of the cardiac cycle phase boundary.
Fig.3. Basics of graphical differentiation in mathematics.
A local maximum (or a local minimum) of a derivative graph can be found out on the derivative curve as a function. At the local minimum or maximum point, we are dealing with energy change rate, i.e., energy decreasing or increasing. The same is applicable to our recorded curve: in this case, it reflects the maximum (or minimum) of the rate of changing process recorded.
Fig. 4. Derivative of a real ECG
4. Upon measuring durations of each cardiac cycle phase and substituting them into the hemodynamic equation by G. Poyedintsev ‚Äď O. Voronova, the following 7 phase-related volumes of blood are calculated as listed below:
SV ‚Äď stroke volume (ml);
MV ‚Äď minute volume (l/min);
PV1 ‚Äď volume of blood entering the ventricle in the early diastole (ml);
PV2 ‚Äď volume of blood entering the left ventricle in the atrial systole (ml);
PV3 ‚Äď volume of blood ejected by the ventricle during the rapid ejection phase (ml);
PV4 ‚Äď volume of blood ejected by the ventricle during the slow ejection phase (ml);
PV5 ‚Äď volume of blood (SV fraction) pumped by the ascending aorta as peristaltic pump (ml).