Catheter Ablation of Long‐Lasting Persistent Atrial Fibrillation: Critical Structures for Termination

Abstract

Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.

Catheter Ablation of Lone Atrial Fibrillation

“…However, inconsistency in the ablation technique and technology, different definitions of success and arrhythmia recurrence and differences and limitations in the methods of clinical follow-up after the procedure complicate the realistic appreciation of the results and, therefore, it is not surprising that significant differences in outcome of AF ablation exist in the published series [3]. Besides that, the long term outcome data after ablation of AF are still scarce and limited to period of only 3-8 emphasizes the importance of creating irreversible ablative lesion in the first procedure [25,28,29,47]. Indeed, the inability to create permanent and continuous ablative lesions in the first procedure represents one of the principal limits of the actual ablation technology.…”

“…It is considered that artery occlusion was mediated by direct thermal injury of its wall with edema or spasm and/or cumulative injury from previous procedure. In complex AF procedures, ablation of substrate is not limited to the LA [25]. It has been shown that RF ablation of cavo-tricuspid isthmus could be accompanied by temporary but significant reduction of fractional flow reserve (FFR) in 21.2% of patients, or rarely by acute occlusion of distal segment of right coronary artery with inferior myocardial infarction [188,189].…”

“…CFAE can be identified by visual inspection or automatically by dedicated software of electro-anatomical mapping system. The result of local ablation and elimination of CFAE is a prolongation of AF cycle length and, finally, termination of AF with conversion into "organized" atrial tachycardia/flutter or sinus rhythm [25,51]. AF substrate also can be modified by the linear atrial ablation, which imitates the surgical MAZE procedure, in form of the roof line and, eventually, the inferior line on the LA posterior wall, connecting both superior and both inferior PVs.…”

“…There are three basic strategies for modification of AF substrate: LA defragmentation by ablation of the complex fragmented atrial electrograms (CFAE), linear ablation of LA and ganglionated plexi ablation [3,[21][22][23][24][25][26][27][28][29]. CFAE are the electrograms during AF which have short cycle length (<120ms) or which are fractionated into two or more components, or show continuous atrial electrical activation [50].…”

Characterization of Left Atrial Tachyarrhythmias in Patients Following Atrial Fibrillation Ablation: Correlation of surface ECG with Intracardiac Mapping

“…2,3 Sometimes lesions may need to be delivered within the CS in order to achieve block although this may not always be necessary to terminate the flutter. 7,18,19 Lesions extending from septal MA to the right inferior PV may also achieve flutter termination but these are more difficult to deliver both on account of difficulty in catheter deployment in this area and the relatively longer extent as compared with the In rare instances involving reentry around the veins, following PV isolation additional lesions extending from right PVs to the fossa or left PVs to the appendage and / or the MA may be required to terminate the arrhythmia. 7,18 In instances where one or more of the above macroreentrant circuit is suspected but not confirmed (changing tachycardias, disorganization to AF or organization to sinus rhythm during entrainment), a combination of the above lesion sets can be empirically deployed.…”