Open Access e-Journal Cardiometry No.16 May 2020
We should mention that Cardiometry is a fine diagnostics tool to assess heart life expectancy. Our experts, using Cardiocode in “red zones” in intensive care units, have confirmed effectiveness of noninvasive measuring of the hemodynamics data on the cardiovascular system performance in critical patients with different severity degrees. The medical staff involved had a possibility not only to monitor the state in each critical patient, but also to predict and control the progression of a disease. We are going to publish some results of this pilot study in our next issues.
We should mention that Cardiometry is a fine diagnostics tool to assess heart life expectancy. Our experts, using Cardiocode in “red zones” in intensive care units, have confirmed effectiveness of noninvasive measuring of the hemodynamics data on the cardiovascular system performance in critical patients with different severity degrees. The medical staff involved had a possibility not only to monitor the state in each critical patient, but also to predict and control the progression of a disease. We are going to publish some results of this pilot study in our next issues.
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ORIGINAL RESEARCH Submitted: 20.02.2020; Accepted: 28.03.2020; Published online: 21.05.2020
Evaluation of general
repolarization of cardiomyocites
with biphasic pulses of different
shapes
Nikolay N. Chernov 1 *, Aleksandr A. Bezverkhii 1 ,
Vladimir I. Timoshenko 1
1
Southern Federal University
Russia, 347900, Taganrog, Shevchenko st. 2
*
Corresponding author:
e-mail: nnchernov@sfedu.ru
phone: +7(928) 908-11-77
Abstract
According to data provided by the European Resuscitation
Council (ERC), 76% of sudden cardiac arrests should be attributed
to ventricular fibrillation [1-3]. The main treatment of this disease
is an immediate cardiopulmonary resuscitation, one of the
components of which is a defibrillation of abnormal rhythms.
The paper presents an analysis of advanced shapes of biphasic
pulses, which have found a widespread application and have
been clinically tested. The aim is to study the main parameters
of the impact of different shapes of the existing pulses and their
due consideration in a development of a defibrillator. An evaluation
has been performed using defibrillators Fluke Impulse
7000DP and device Impulse 7010 designed to simulate different
loads. Evaluated has been the shape of each of 7 biphasic
pulses, the amplitude and exposure time of each of different
signal phases. Upon results of the conducted analysis, some
recommendations on cardiopulmonary resuscitation have been
prepared; in particular, the necessity to maintain a constant current
density of 14 -16 A, delivered for 4 -5 ms, is proposed. The
maintenance of these parameters can be provided using the
current stabilization technology (CST).
Keywords
Biphasic pulse, Defibrillation, Cardiomyocytes repolarization,
Ventricular fibrillation, Current-controlled defibrillation
Imprint
Nikolay N. Chernov, Aleksandr A. Bezverkhii, Vladimir I. Timoshenko.
Evaluation of general repolarization of cardiomyocites with biphasic
pulses of different shapes. Cardiometry; Issue 16; May 2020;
р.80-84; DOI: 10.12710/cardiometry.2020.16.8084; Available from:
http://www.cardiometry.net/issues/no16-may-2020/evaluation-
of-general-repolarization
Introduction
Sudden cardiac arrest (SCA) is one of the leading
causes of death in developed countries. According to
data provided by the European Resuscitation Council
(ERC), in 2015, 76% of sudden cardiac arrests should
be attributed to ventricular fibrillation (VF) [1-3]. A
marked increase in the VF share has been identified
after taking active measures to apply automated external
defibrillators (AED) [4-5] available at all the
important public places. The main treatment of SCA
is an immediate cardiopulmonary resuscitation (CPR)
and defibrillation of abnormal rhythms, such as VF and
ventricular tachycardia (VT). The AED availability and
an early, within 3-5 minutes, defibrillation can raise a
survival rate up to 50-70% [3,5,6].
The basic characteristics of defibrillators operating
in manual and automated modes are the range of energies
that the defibrillator is capable to produce, their
pulse shape and their charging/discharging time. The
first discharge shock energy for adults is 150 J with a
possible further increase in case of inefficacy [7-9]. For
adolescents aged 1 to 8 years in case of using manual
defibrillators, it is necessary to use energy from 4 to 9
J / kg in the range of 50 -75 J [10-13]. As to the shape
of the pulse used, they are biphasic in all modern defibrillators.
A higher efficiency of the bipolar pulse in
comparison to the monopolar one is supported by a
large number both of theoretical and practical works
[14-16]. The basic concept of the time requirement is
to minimize it from the beginning of the rhythm detection
to the readiness to discharge. Based on the duration
of the proper defibrillation it is found that the
time and amplitude of the second pulse phase should
be lower. This parameter varies from one manufacturer
to another, and each of them submits its own justifications
of why to produce its own type of circuitry.
The pulse energy, its shape and the time should be
optimal and serve two purposes. The first purpose is
to provide a complete and simultaneous repolarization
of all cardiomyocytes, and the second one is to
reduce damaging negative effects made on cardiomyocytes.
The major damage is done to mitochondria of
cardiomyocytes, cristae of which are destroyed due to
80 | Cardiometry | Issue 16. May 2020
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