AV reentry tachycardia
| Classification according to ICD-10 | |
|---|---|
| I47.1 | Supraventricular tachycardia: AV-junctional |
| ICD-10 online (WHO version 2019) | |
The AV reentrant tachycardia (AVRT) is a form of supraventricular arrhythmia , by an accessory pathway resulting in a circular excitation between atrium and ventricle. AV reentry tachycardia should not be confused with AV nodal reentry tachycardia (AVNRT), since this is triggered by a different mechanism and treated differently.
etiology
The cause of AVRT is a circular excitation, in which, compared to the normal heart, an additional conduction path between atrium and ventricle leads to a recurring excitation of the AV node or a premature excitation of the ventricle (depending on the direction of conduction, see pre-excitation ). This leads to a rapid ventricular rate independent of the sinus node .
Symptoms
The affected patients often report palpitations and a feeling of weakness. Occasionally there is also shortness of breath and syncope . The course is usually seizure, but longer-lasting tachycardia can also occur.
Diagnosis
The ECG usually shows a narrow, but occasionally also broad (see pre-excitation ) QRS complex with a frequency of 160–200 beats per minute. P waves cannot be seen. If there is no simultaneous atrial fibrillation , the intervals between the beats are regular. If the AVRT is based on open WPW syndrome , a delta wave is typically seen in the phases between the tachycardia episodes .
therapy
If the vagus stimulus is unsuccessful , a drug cardioversion with adenosine can be carried out with a regular narrow complex rhythm if the patient is impaired accordingly .
If the tachycardia is irregular (with simultaneous atrial fibrillation), the administration of AV-blocking drugs such as adenosine , verapamil , digitalis and beta blockers is absolutely contraindicated, as otherwise ventricular fibrillation can occur. In such a case and if therapy is resistant, therapy with ajmaline or alternatively propafenone can be used.
If there is a life-threatening impairment of the cardiovascular function, electrical cardioversion can also be performed.
A catheter ablation as part of an EPU can obliterate the causal pathway and effectively prevent recurrence.
