What is AV (atrioventricular) ablation done for in treatment?

Atrioventricular (AV) Ablation in Treatment

AV ablation is primarily performed to control ventricular rate in patients with symptomatic atrial tachyarrhythmias (particularly atrial fibrillation or flutter) that are refractory to or intolerant of medical therapy, resulting in improved quality of life and reduced healthcare utilization. 1

Primary Indications for AV Ablation

• AV junction ablation (producing complete AV block) is well-established as a means of controlling ventricular response in patients with poor rate control despite medical therapy 1
• It is indicated for patients with symptomatic atrial tachyarrhythmias (particularly atrial fibrillation) when drugs are not tolerated or the patient does not wish to take them 1
• AV nodal ablation in conjunction with permanent pacemaker implantation significantly improves cardiac symptoms, quality of life, and reduces healthcare utilization for patients with symptomatic AF refractory to medical treatment 1
• It is also indicated for patients with symptomatic nonparoxysmal junctional tachycardia that is drug resistant 1

Procedural Considerations

• Complete AV block by radiofrequency ablation of the AV junction has an efficacy rate of 70-95% (usually 87% or more) 1
• Following AV junction ablation, permanent pacemaker implantation is required 1
• For patients with chronic atrial fibrillation, a VVIR pacemaker is typically used, while patients with paroxysmal atrial fibrillation may benefit from DDDR mode-switching devices 2, 3
• Selective ablation in the posteroseptal and midseptal AV node regions has been used to control ventricular response without producing complete AV block 1

Clinical Outcomes

• 88% of patients report subjective improvement after AV junction ablation 2
• The number of hospitalization days per year is typically reduced (from 17 to 7 days in one study) 2
• Antiarrhythmic drug use is reduced by approximately 75% 2
• Exercise capacity increases and left ventricular ejection fraction may improve, particularly in patients with previously depressed myocardial function 3

Complications and Risks

• Complication rates are generally less than 2%, with procedure-related deaths estimated at 0.1% 1
• Late sudden death may occur following AV junction ablation, though this risk may be lower with radiofrequency ablation compared to DC shock ablation 1
• Other potential complications include inadvertent complete AV block when only modification was intended 1
• The most common complication in AV node modification has been the development of heart block through inadvertent ablation of both fast and slow AV nodal pathways 1

Special Considerations

• For patients with paroxysmal atrial fibrillation, DDDR pacemakers with automatic mode switching are recommended 2
• For patients with chronic atrial fibrillation or those requiring DC conversion, VVIR pacemakers are typically used 2
• Despite the need for lifelong pacemaker dependency and continued anticoagulation, AV nodal ablation is considered cost-effective, with break-even achieved approximately 2.6 years after the procedure 2, 3

Alternative Approaches

• For atrial flutter that often coexists with atrial fibrillation, cavotricuspid isthmus (CTI) ablation may be performed instead of or in addition to AV nodal ablation 4
• For AV nodal reentrant tachycardia (AVNRT), selective ablation of slow or fast pathways rather than complete AV nodal ablation is the preferred approach 1, 5