Pacemaker - what is it from a medical point of view? First of all, it is a miniature electronic device that normalizes the work of the heart muscle. The pacemaker of the heart provides the optimal number of contractions necessary for normal functioning. The device is able to overcome the electrophysiological separation of the atria and ventricles, the so-called atrioventricular block, and thus stabilize the work of the heart.
History of creation
Pacemaker - what is it for a physiologist? How can this device be used in terms of impact on pathological processes in the cardiovascular system of the human body? Scientists thought about the use of weak pulses of electric current to eliminate arrhythmias at the end of the 19th century. However, the lack of technologies for the generation of electrical sends in a minimized value did not even allow to begin research in this direction.
Only in the first half of the 20th century, physiologists were able to begin to study the effect of electrical impulses on the activity of the heart. The pioneer in this area was the Italian researcher Luigi Galvani. Later, Russian physiologists N.E. Vvedensky and Yu. M. Chagovets began studying the possibility of using weak electric current discharges for the treatment of certain heart diseases.
In 1927, American cardiologist Albert Hyman designed the world's first electro-mechanical device that maintains the stability of the rhythmic work of the human heart. The device weighed more than three hundred grams, the device was suspended on special belts and hid under clothes. However, the electric stimulator functioned well, and soon its serial production was established.
First results
Pacemaker - what is it for Albert Hyman, creator of the device and his colleagues dealing with cardiac arrhythmias? First of all, this is the first stage in a long process of studying electrical methods that could be put at the service of medicine.
The practical application of Hymen stimulator in an emergency took place in 1951, when after the operation it was possible to save a patient with developed transverse heart block and attacks of extrasystole. Nevertheless, the patient had to stay in the hospital for a long time, since he could not move freely with a rather bulky apparatus on his body and, in addition, he needed constant monitoring by the medical staff.
Implant stimulator
World cardiology centers have joined forces to create a compact electrical stimulator that would weigh no more than 80 grams. In 1958, a group of Swedish scientists led by Dr. Rune Elmqvist created a miniature Siemens Elem. The stimulator was enclosed in a thin-walled case made of titanium alloy and could be implanted under the skin. However, the energy intensity of the Swedish invention was small - the battery provided pulses for only 18 months, after which the patient was forced to perform an operation to replace the power source.
Creation of domestic EX
Finally, a pacemaker - what is it from the point of view of the patients themselves? Of course, this is a life-saving device that prolongs the life of cardiological patients suffering from various rhythm disturbances. The heart muscle, functioning in the right tone, is the key to the stable operation of the entire circulatory system of the body.
In 1960, the Soviet academician A.N. Bakulev turned to the leading technical centers of the USSR with a proposal to create cardiological stabilization apparatuses. The first to respond were the Design Bureau for Precise Engineering in Engineering, which had the status of a defense enterprise. In a short time, prototypes of EX were created, technological tests were carried out, and already in December 1961 the first Russian-made pacemaker EX-2 Mosquito was successfully implanted into a patient suffering from complete atrioventricular heart block. The pacemaker "Mosquito" was produced for 15 years, thousands of sick people were saved thanks to a reliable miniature device.
The high mortality rate due to cardiovascular diseases in the USSR, noted at the end of the 50s, began to decline. A cardiac pacemaker, reviews of which were generally positive from patients, quickly gained popularity.
The novelty was constantly improved, the characteristics of the domestic EX improved. At the end of 1962, new designs appeared recommended by the Ministry of Health for mass production. Thus, a cardiac pacemaker created in Russia, whose quality reviews were positive, began to be released at once at several medical enterprises.
External pacemaker
Before implantation of the stimulator-implant, the patient can receive preliminary assistance using an external contact device consisting of two plates that are located on both sides of the chest: one in the front in the heart, the other on the back, under the left shoulder blade. An impulse passing through the sternum causes smooth muscles to contract on both sides, as well as the heart muscle. This method causes a feeling of discomfort in the patient, but as a temporary method of stabilizing the rhythm of heart contractions is quite appropriate. The inconvenience of the method of external stimulation also lies in the fact that the patient should not be left unattended, especially if he is in an unconscious state. Installing a pacemaker working on an ongoing basis, requires special training, which takes several weeks.
Temporary endocardial stimulation
The principle of such an effect on the heart muscle is the introduction of a probe electrode into the cavity of the heart. For such operations, a sterile kit is created from the conductor and the probe itself, which is delivered through the venous channel to the heart. The end of the electrode is installed in the right atrium, and its opposite, proximal end is connected externally to the source that generates electrical pulses.
Installing a pacemaker on a temporary basis is usually used when there is no time for more radical methods. After normalizing the patient’s cardiac activity, one can proceed with implantation of a permanent device.
How permanent pace is implanted
A pacemaker, the implantation operation of which is a small surgical intervention, is designed for long-term use. Implantation is carried out, as a rule, with local anesthesia. The whole process is divided into several stages. First, an incision is made on the skin and fiber and a vein is secreted. Then, the desired number of electrodes, which are placed in the heart chambers, are drawn to the heart. After the introduction of the conductors, a check is made of all the data: sensitivity, stimulation threshold, optimal arrangement of threads conducting pulses. Then the electrodes are fixed, a bed for the pacemaker is formed, and the device is implanted.
In some cases, the implant does not immediately take root, there may even be slight rejection, but the inflammatory process quickly subsides under the influence of conventional drugs, and the patient continues to live a normal, familiar life.
The main functions of EX
The device is an electronic device mounted in a compact metal case. The microprocessor is powered by a battery designed for several years. The principle of action of domestic ECS is to respond to the absence of another contraction of the patient’s heart muscle. The pacemaker is designed so that the pulse sent by its electronic brain is practically not late - the time difference is hundredths of a second.
During normal heart function, the device behaves indifferently - it does not send impulses. There is a group of pacemakers that are capable of frequency adaptation. A sensor sensitive to changes in patient activity is embedded in such devices. In fact, this is an acceleration sensor, an accelerometer that responds to changes in the parameters of the electrocardiogram and respiratory rate. During physical activity, the pacemaker of the heart sends out quick pulses.
Recent models of ECS are able to accumulate data on the work of the heart, which can then be displayed on a monitor or digital media for analysis. This function enables the doctor to prescribe the optimal drug treatment, as well as select the parameters of the pacemaker. Revision of such devices should be carried out at least once every six months. A pacemaker, the installation price of which is quite affordable for a person with an average income, can be replaced if necessary.
Transesophageal pacing
To diagnose the phenomena of arrhythmia in a patient, a testing system using a probe is used. A special conductor with an electrically conductive tip is inserted into the esophagus. The probe stops at the point of contact of the heart, or rather the left atrium, with the esophagus. Then the generator is turned on, which delivers pulses of different frequencies. The meaning of such studies is to detect the presence of coronary heart disease. Heart palpitations under the influence of electrical impulses may show aversion to the load on the heart muscle.
Transesophageal stimulation is quite universal, with its help it is possible to diagnose a number of cardiological diseases. In some cases, NPES allows treatment: to remove paroxysmal tachycardia, to relieve atrial flutter, to provide temporary stimulation for bradyarrhythmia, accompanied by a rare pulse, to eliminate the sinus node weakness syndrome . Some manipulations are possible only with a deeper location of the probe in the esophagus.
Pacemaker: Surgery Cost
Installing an EX in Russia can cost from 65 to 650 thousand rubles. This amount consists of the cost of the device itself, the cost of implantation and the postoperative period. The pacemaker itself, the price of which is determined by the manufacturer, can be relatively inexpensive (from 20 thousand rubles). The choice of model is provided to the patient. It is better to purchase a pacemaker, reviews of which are mostly good. These are devices from Medtronic, StJudeMedical, Guidant, and Biotronic.