AV nodal ablation

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ayokunle Olubaniyi, M.B,B.S [2]

Synonyms and keywords: AVNA

Overview

Atrioventricular nodal or AV junction ablation is a procedure by which the electrical pathways that connect the atria to the ventricles are modified or interrupted in order to restore a normal cardiac rhythm. This procedure creates a disconnect between the upper chambers (which controls the heart rate and rhythm) and the lower chambers (ventricles). Due to the invasive nature of the procedure and the requirement for a pacemaker implantation, AVNA is mostly as a fallback treatment in patients with atrial fibrillation that is refractory to medications, or have developed side effects to the medications.

Indications

• Control of ventricular rate in atrial fibrillation
• Recurrent symptomatic atrial tachycardia in which all therapeutic options have failed

Procedure

During this procedure, a special catheter is passed through the femoral vein into the heart under fluoroscopic guidance. Once the catheter is in place, a small amount of radiofrequency energy or heat is applied adjacent to the AV node in order to destroy it or create a scar which permanently blocks the entry of fast impulses from the atrium. After a successful ablation, the ventricles will no longer respond to the impulses from the atria, in other words, they beat independently of each other. The ventricular rate is about 40 beats per minute which may be too slow for adequate perfusion under exercise conditions, therefore, an implantation of a permanent pacemaker is required.

Complications and Prognosis

• Development of inappropriate sinus tachycardia. RF ablation in the anterior, mid, and posterior regions of the low interatrial septum may disrupt preganglionic or postganglionic parasympathetic fibers located in these regions that are destined to innervate the sinus node.
• Ventricular fibrillation