Pacemaker tachycardia (PMT) is a heart rhythm disturbance associated with an arrhythmia group associated with pacemaker operation (ECS). It is considered the most frequent complication of two-chamber cardiac stimulation.
During the two-chamber electrostimulation, initialization of the atria and ventricular contractions is performed. The installation of a permanent EKS is carried out with AB blockade, dysfunction of the sinus-atrium node.
Patients before implantation of EKS usually tell about possible complications and should react when they appear.Nevertheless, not everyone who wants to go through the procedure for the introduction of the pacemaker is aware of the risk of pacemaker tachycardia
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escription of pacemaker tachycardia
Pathology develops against the backdrop of retrograde depolarization of the atrium, which occurs due to premature depolarization of the ventricle. Also, in the process of stimulation of the ventricular contraction, which occurs at the time of acute ECS, favorable conditions for the occurrence of PMT are created.
Tachycardia during the use of EKS may be not only pacemakers but also spontaneous. The following criteria help to distinguish one another:
- after the pacemaker is disconnected, the tachycardia disappears or its severity decreases;
- there is a stable clutch interval between the ventricular complexes on the ECG;
- all the complexes are practically identical with each other.
Two-chamber electrostimulators combine the interaction of two channels, stimulation and "sensation", so the arrhythmias that develop under their activities, including tachycardia, can run quite complicated.
Symptoms of pacemaker tachycardia
There is no specific symptomatology in pacemaker tachycardia. The patient may feel attacks of the heart beat, which are not removed by standard methods of stopping - vagal methods, the use of nitroglycerin or sedative drugs.
Together with a rhythm disturbance in patients with EKS, a pacemaker syndrome can be determined, which includes the following symptoms:
- disorder of the psycho-emotional sphere;
- general weakness, increased fatigue;
- sharp changes in blood pressure;
- dizziness and headaches;
- deterioration of vision, hearing, other sensory organs;
- insomnia and anxiety at night;
- deterioration of hemodynamics, which is manifested by congestive events in the lungs and the circulatory system.
Paismecker syndrome and arrhythmias, including tachycardia, are often manifested by the general decline in the strength of the patient. It is difficult to perform the usual work, while the general condition may deteriorate physical activity.
Causes of the occurrence of pacemaker tachycardia
In some patients, before the implantation of the electrostimulator, ventriculoatrial conduction could be observed. If this pathology is not accompanied by an echo-contraction, then ventricular stimulation does not usually cause arrhythmias, including PMT. But in the case of two-chamber stimulation, the presence of ventriculo-uterine conduction may be the cause of circular pacemaker tachycardia.
Other reasons for the appearance of PMT may be the same factors as in the case of single-chamber stimulation:
- the heart muscle has lost its ability to perceive electrical impulses;
- the thresholds for stimulation or resistance have risen sharply;
- the electrodes broke or changed their location;
- after an implantation of an EC, an infectious complication has developed;
- stimulation of the diaphragmatic nerve occurred;
- the battery of the device is prematurely discharged;
- developed pneumothorax or tamponade of the pericardium.
Types / photos of pacemaker tachycardia
Pathological disorder of the rhythm manifests itself in two variants:
- Tachyarrhythmias that occur due to the effects of stimulants (ventricular tachycardia, ventricular fibrillation, atrial fibrillation, supraventricular tachycardia).
- Tachyarrhythmias mediated by stimulants.
"Infinite" circular tachycardia - refers to PMT mediated by stimulants. Its mechanism of development is similar to a reciprocal tachycardia developed against the backdrop of WPW syndrome. In some cases, the extrasystole, which occurs in the atria, is not the period of availability of a two-channel pacemaker. It promotes ventricular stimulation, after which the retrograde wave propagates to the atrium. They at this time left the refractory state, therefore a new wave of excitation comes to the ventricles. From here again the electric stimulus is directed to the atrium and so "infinitely". Due to its typical mechanism of development, a similar pathology is also called macroretrium tachycardia.
The development of another variant of the pacemaker tachycardia is related to the atrioventricular blockade, with the background of which patients with implanted two-channel EKS produce tremor or atrial fibrillation. During the creation of large waves of fibrillation or flutter the device catches them, and then creates ventricular stimuli with irregular and maximum permissible frequency. In such a situation, the EKS acts as an artifical additional path.
Autonomous pacemaker tachycardia is an option of mediated PMT. It is characterized by trigger activity. At the heart of its development is the feeling of natural heart impulses.
Diagnosis of pacemaker tachycardia
The definition of PMT involves cardiologists who have installed the pacemaker, as well as doctors of functional diagnosis, which help with the definition of a variety of tachycardia. During the diagnosis, it is important to come to the unequivocal conclusion: in the development of PMT, a pacemaker or a thorough evaluation of the conditions for cardiac stimulation should be conducted.
Treatment and prevention of pacemaker tachycardia
First of all, actions are performed to regulate the refractory atrial period. To this end, an adequate extension of the atrial refractory is used, which helps to ensure the correct transition of the retrograde ventricular pulse during the period of repolarization in which the atria are located.
Additionally, it is important to determine the duration of the ventriculoatrilic conduct. This is especially true for patients with a pacemaker without a function such as automatic stopping of PMT, which may present a risk due to the high risk of hemodynamic disturbances.
Specific prevention of pacemaker tachycardia is absent. It is important for patients to observe the rules for monitoring the state of the pacemaker. In particular, with ECS can not practice electrotherapy, radiation therapy, diathermy, percutaneous electrostimulation. In everyday life you need to carefully handle electrical appliances so that they do not touch the area of the EKS.
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