“Shock”: why he can revive a person

Cardiac arrest is a deadly pathology, for the elimination of which there are only a few minutes. In such a situation, the organ stops contracting and pumping blood, and if measures are not taken to restore the heart rhythm, death occurs. Emergency cardiological care also includes electropulse therapy, that is, sending an electrical discharge to the region of the heart. But why does it start with an electric shock and in what cases is this method used?

It always helps

Cardiac arrest can occur for various reasons. But it is divided into at least 2 types – with the presence or absence of the bioelectric activity of the organ. Doctors of the Federal Scientific and Clinical Center for Resuscitation and Rehabilitation are reminded of this. In such a situation, when there are no, even minimal contractions of the ventricles of the heart, that is, its bioelectrical activity is completely absent, resuscitators do not perform electropulse therapy.

It is impossible to “light up” a completely stopped heart with current, like a dead car battery. But in the case when the electrical activity of the organ is still present, and even if it manifests itself in the form of weak arrhythmic and chaotic contractions of some of its sections, a medical device that generates a short high-voltage pulse may be sparing.

How electricity affects

The fact that an electric shock is able to restore the work of the heart, doctors around the world understood only closer to the middle of the 20th century. It all started with the study of the Swiss doctor, neurologist and physiologist Jean-Louis Prevost, who in 1899 found out that in mammals it is possible to stop heart contractions through the action of In particular, the doctor noted that in adult and healthy animals it is possible to completely stop ventricular fibrillation of the heart.

Although usually at the moment of damage to cardiac activity, a whole and initially healthy organ does not immediately stop its beating, but fibrillation occurs – chaotic contractions of myocardial fibers with a complete absence of coordinating contraction of the stomach In this state, the heart ceases to perform its pumping functions, but even in this case, death does not occur instantly. However, insufficient time and / or completely stopped blood supply to the body still leads to it.

But if current shocks can arrange fibrillation, then they are also able to translate pathologically insufficient contractions of the ventricles of the heart into a coordinated, rhythmic work. Approximately, many European medical researchers and among them the Russian physiologist, the Soviet doctor of biological sciences and professor, Georgy Semenovich Yunev decided so. He, like many of his colleagues, suggested using an electrical method to restore the normal activity of a fibrillating heart.

A short – up to 10 milliseconds electrical discharge of a special device, with a voltage of 6000-7000 V and a power of 200-360 J, causes the excitation of most of the cardiomyocytes and their synchronization, when the tissue cells are electrically resistant to the channels. Thus, with a weak and arrhythmic work of the ventricles, such an effect of the current makes them contract strongly and further, normalization of the rhythm of the work of the whole heart is possible.

Current that saves lives

An electrical device that can help a fibrillating heart and save a person is called a defibrillator in Russia. Until the 1970s, all over the world, resuscitation using an electrical impulse was carried out extremely rarely and only in large specialized clinics, since the defibrillator was a huge unit, connected exclusively to the electric network.

But in the mid-1960s, a Northern Irish cardiologist, MD, Frank Pantridge, along with his colleague John Geddes, first invented a battery-powered device that weighed 70 kg. And then, also in his clinic in Belfast, an outstanding Irish doctor designed a defibrillator, the mass of which did not exceed 3 kg. Since then, resuscitation with the use of electropulse therapy, doctors around the world have been able to carry out both in ambulances and on the streets. And it saved a lot of human lives.

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