Targets for ablation in AF
Main targets for ablation in AF (atrial fibrillation), especially paroxysmal AF are the pulmonary veins. Foci in pulmonary veins are thought to be the main triggers of AF. Targeting additional targets may be needed in persistent AF. These targets include ligament of Marshall, superior vena cava and left atrial appendage. Mapping to locate complex fractionated atrial electrograms (CFAE) and ablation if found is another strategy for substrate modification. These are presumed regions of scars with low amplitude electrograms. Similarly, targeting regions of atrial scars located on magnetic resonance imaging may also be attempted.
Atrioventricular node (AV node) ablation may be considered when effective rate control in AF cannot be achieved by medical therapy and leads to tachycardia induced cardiomyopathy. AV node ablation can improve symptoms, quality of life and health care utilization. But anticoagulation has to be continued and there is an obligatory pacemaker dependence. Some of them may develop pacing induced cardiomyopathy and heart failure due to persistent right ventricular pacing. In those with severe left ventricular dysfunction, cardiac resynchronization therapy (CRT) is needed along with AV node ablation .
- Chung MK, Refaat M, Shen WK, Kutyifa V, Cha YM, Di Biase L, Baranchuk A, Lampert R, Natale A, Fisher J, Lakkireddy DR; ACC Electrophysiology Section Leadership Council. Atrial Fibrillation: JACC Council Perspectives. J Am Coll Cardiol. 2020 Apr 14;75(14):1689-1713.
- Curtis AB. Biventricular pacing for atrioventricular block and systolic dysfunction. N Engl J Med. 2013 Aug 8;369(6):579.