The nodal tachycardia is more commonly known under the other term - atrioventricular nodal recurrence of tachycardia (AWURT). In the development of the disease in rare cases, about 15%, the organic pathology of the heart is determined. Most often, the disease is diagnosed in adults, much less often - in children.
Most of the patients with AVURT, about 70%, are women. They have a disease earlier than men, an average of 30 years.
In the process of determining the pathology used the same methods as with other forms of tachycardia. It is important to begin the treatment of AVURT in a timely manner, so that, afterwards, it was not necessary to ask the question of how dangerous nodal tachycardia is. For this purpose, special therapies are used, medicated and minimally invasive.
Video AV nodular tachycardia
Description of nodal tachycardia
The development of pathology is associated with an impulse in an atrioventricular node. Functional features of the AV node share the path of the impulse to be fast and slow. They consist of certain groups of fibers with different electrophysiological properties. Similar features of the structure of the AV node contribute to the development of the excitation wave path in this region of the reentry type.
The nodal tachycardia is usually triggered by an extraordinary reduction of the atria, often extrasystole. Next there is a blockade of the fast path, and the pulse goes down the slow path to the ventricles. When it becomes possible, the excitation wave quickly passes to the atrium, contributing to their re-contraction, and returns slowly. A peculiar "loop of re-enter" is formed, which is the basis of the occurrence of tachycardia.
Symptoms of nodal tachycardia
A characteristic feature of nodal tachycardia is the presence of sudden attacks, which are accompanied by a rhythmic rapid heartbeat. Paroxysm can have a different duration - from a few seconds to one or two hours. The frequency of seizures is also different, in some patients, tachycardia can occur every day, others - several times a year.
Heart rate at nodal tachycardia is up to 250 beats per minute. In addition to the heartbeat during an attack, the patient may be disturbed by dizziness, anxiety, and anxiety. The pulsation of large vessels in the neck is often noted.
Causes of nodal tachycardia
Many experts agree that nodal tachycardia refers to congenital pathologies. Today, the study of the causes of the disease is aimed at finding mutated genes, which during the prenatal laying of organs affect the cleavage of the atrioventricular node.
There are risk factors that increase the likelihood of ADHD presentation:
- frequent stresses;
- bad habits (smoking, alcohol abuse);
- physical overvoltage.
Relatively unfavorable is the frequent use of strong coffee, because not all patients have this habit contributing to a violation of the rhythm.
Types / photos of nodal tachycardia
There are three types of nodal tachycardia, which are divided among themselves, taking into account the peculiarities of the passage of the pulse through the "loop of re-entry".
- A typical AWURT form is also known as slow-fast. The excitation wave passes in a passive way slowly, and retrograde fast.
- The form AWURT fast-slow - is characterized by anterograde pulse conduct in a fast way, and retrograde - in a slow way.
- The form AWURT is slow-slow - in the formation of pathology involved two slow paths of conduct, in which the impulse moves anterograde and retrograde.
The second and third forms of nodal tachycardia are found relatively rarely, in 5-10% of the total number of pathology definitions.
Diagnosis of nodal tachycardia
Electrocardiography is used in the examination of patients, which is the most informative method. In a normal condition, patients have ECG on sinus rhythm and no changes are noted. During paroxysm, the following symptoms of AUURT are determined:
- increased heart rate 140-250 beats per minute;
- the tooth P has a retrograde location and is often superimposed on the ventricular complex. Alternatively, the location of the tooth after QRS;
- in the thoracic nodes pseudo-r can be observed.
All patients who have nodal tachycardia have been determined, electrophysiological examination is obligatory.
Electrocardiogram video at AV node reciprocal re-entry tachycardia (AVRT, AVURT)
Treatment and prevention of nodal tachycardia
In the development of an attack, treatment is primarily directed at its cure. For this purpose, the reflex effect is used in the form of vagal tests and massage of carotid sinuses. It is also possible to receive medical medications. Most often verapamil helps, not so effective, but it is still recommended to use adenosine, novocainamide and obzidan. In mild cases, medications are taken in pills, severe attacks of tachycardia should be stopped by intravenous administration of these drugs.
Prevention of nodal tachycardia is to prevent the development of attacks, which can be done in two ways. One is a practically life-long treatment of antiarrhythmic drugs, which doses need to be corrected in a timely manner. Sometimes it is necessary to change the combinations of medicines, choosing the most effective, consisting of arrhythmics of different groups.
The standard combination of antiarrhythmic drugs is digoxin, beta-blockers, calcium channel blockers.
Radiofrequency ablation is the second method of treating Avourt and today the most effective. A qualitatively performed operation allows the patient to not take arrhythmias at the nodal tachycardia. As many practitioners of RFA surgeons report, the operation is successful in almost 99% of cases. Of the complications, only an AB blockage is indicated, the rate of development of which is 1%. During the intervention, the ablation of the slow paths fibers in the area of the Koch triangle is carried out.