page_title: AV nodal reentrant tachycardia
section_title: Arrhythmia termination
hierarchical_section_title: AV nodal reentrant tachycardia / Treatment / Arrhythmia termination
context_page_description: AV-nodal reentrant tachycardia is a type of abnormal fast heart rhythm. It is a type of supraventricular tachycardia, meaning that it originates from a location within the heart above the bundle of His. AV nodal reentrant tachycardia is the most common regular supraventricular tachycardia. It is more common in women than men. The main symptom is palpitations. Treatment may be with specific physical maneuvers, medications, or, rarely, synchronized cardioversion. Frequent attacks may require radiofrequency ablation, in which the abnormally conducting tissue in the heart is destroyed.
  AVNRT occurs when a reentrant circuit forms within or just next to the atrioventricular node. The circuit usually involves two anatomical pathways: the fast pathway and the slow pathway, which are both in the right atrium. The slow pathway is located inferior and slightly posterior to the AV node, often following the anterior margin of the coronary sinus. The fast pathway is usually located just superior and posterior to the AV node. These pathways are formed from tissue that behaves very much like the AV node, and some authors regard them as part of the AV node.
context_section_description: An episode of supraventricular tachycardia due to AVNRT can be terminated by any action that transiently blocks the AV node. Some of those with AVNRT may be able to stop their attack by using physical manoeuvres that increase the activity of the vagus nerve on the heart, specifically on the atrioventricular node. These manoeuvres include carotid sinus massage (pressure on the carotid sinus in the neck) and the Valsalva manoeuvre (increasing the pressure in the chest by attempting to exhale against a closed airway by bearing down or holding one's breath).
  Medications that slow or briefly halt electrical conduction through the AV node can terminate AVNRT, including adenosine, beta blockers, or non-dihydropyridine calcium channel blockers (such as verapamil or diltiazem).  Both adenosine and beta blockers may cause tightening of the airways, and are therefore used with caution in people who are known to have asthma. Less commonly used drugs for this purpose include antiarrhythmic drugs such as flecainide or amiodarone.
  If the fast heart rate is poorly tolerated (e.g. the development of heart failure symptoms, low blood pressure or coma) then AVNRT can be terminated electrically using a cardioversion.  In this procedure, after administering a strong sedative or general anaesthetic, an electric shock is applied to the heart to restore a normal rhythm.
caption: AVNRT termination following administration of adenosine
exif: {}