Open Access e-Journal Cardiometry - No.14 May 2019

entry into a cell. This is an aerobic process. In spite
of the relatively high energy consumption, the aerobic
process is properly provided with all metabolism
components [7-9].
The aerobic process is followed by the anaerobic
process, which takes place in tension phase S – L. In the
context of the energetics, the anaerobic process is characterized
by splitting of the carbohydrates. It exhibits
a very high consumption of the energy and cannot be
maintained for a long time. Upon entering the cells, the
Ca ++ ions initiate one more muscle contraction, but it
occurs against the background of the permanent residual
tension. It is similar to the Q – R – S complex. In
this case, in the course of the anaerobic process, the
lactic acid products (lactates) are formed [10, 11].
The Na + and Ca ++ ions, upon entering a cell, create
the conditions for the К+ exit in phase L – j of the
rapid ejection. This is an anaerobic process (the same
case as we have in the previous phase). The shape of
this ECG curve segment is similar to the QRS complex
except for the amplitude of these oscillations: the
amplitude is very low. In terms of the energetics, this
process is weaker than the previous one. To ensure the
process in the next cardiac cycle, the phosphocreatine
must be restored in the diastole within the same cardiac
cycle. Therefore it characterizes the remaining level
of the phosphocreatine [12].
The shape of an ECG curve is a mirror capable
of clearly reflecting all qualitative and quantitative
characteristics of the actual metabolic processes. The
amplitude in each phase is linear with the muscular
fiber contractility. It can be assessed in terms of mathematics
with the use of an ECG curve derivative. By
applying some mathematical apparatus, the cardiac
muscle contraction rate can be found and evaluated
(see Figure 1 herein).
The amplitude of the first order derivative R1
(when measured from the leading edge of the Q – R
interval augmentation) can be treated as an indirect
marker of the actual condition of the aerobic processes
in the cardiac muscle fiber cells of the interventricular
septum. The higher is the amplitude of the derivative,
the more efficient is the muscle performance. So, the
amplitude of the first derivative K1 of the R – S interval
indirectly shows the state of the aerobic processes
in the cardiac muscle fiber cells.
The amplitudes of the derivatives of these phases of
the ECG differ in their informative values despite the
fact that the aerobic processes occurring in the cells
Figure 1. An example: a real ECG curve and the first order
derivative thereof. On the amplitude derivatives: R1 and K1,
R2 and K2, R3 and K3 correspond to interventricular septum
and myocardial muscle contraction rates with reference to
different phases, depending on the aerobic, anaerobic and
phosphocreatine reactions, respectively.
in the interventricular septum and the myocardium
are identical. The interventricular septum starts contracting
the first, and, while contracting, it is “pulling”
the relaxed myocardium, and in the circumstances no
resistance is available. But the contraction of the myocardium
takes place, while the interventricular septum
is kept constrained. Following this way, the difference
in the metabolic consumptions of the above muscle
types can be determined using the ratio as follows:
W1 (aerobic, oxygen) = R1 / К1
Our investigations have shown that the relatively
normal range for this ratio is 0.5 to 0.85 arbitrary
units.
For the anaerobic process, incorporating the lactate
production, the following ratio is applicable:
W2 (anaerobic, lactate) = R2 / К2
In this case, the processes are running against the
background of the permanent cardiac muscle tension
due to pressure applied by blood available within the
ventricles. The normal range for this ratio is 3 to 7 arbitrary
units.
38 | Cardiometry | Issue 14. May 2019