Electrophysiological Characteristics and Catheter Ablation in Patients With Paroxysmal Right Atrial Fibrillation

Abstract

Background— Catheter ablation of the right atrial (RA) substrate has had variable efficacy in curing paroxysmal atrial fibrillation (PAF), suggesting that RA substrate ablation can play an important role in the treatment of atrial fibrillation (AF) in some patients. The aim of this study was to investigate the electrophysiological characteristics and ablation strategy and its results in a specific group of patients with paroxysmal RA-AF. Methods and Results— The study population consisted of 13 patients (8 men; age, 64±15 years) with drug-refractory (2±1 drugs), frequent episodes of PAF. Provocation maneuvers did not reveal any ectopic beat–initiating AF. However, rapid atrial pacing easily induced AF. Activation mapping during sinus rhythm, atrial pacing, and AF was visualized by using a noncontact mapping system. Noncontact mapping revealed RA reentry (6 patients with single-loop circuits and 7 with double-loop circuits) with conduction through channels between lines of block, crista terminalis gaps, and the cavotricuspid isthmus, which could be identified during sinus rhythm and atrial pacing, resulting in fibrillatory conduction in other parts of the RA. The consistency of wavefront activation was confirmed by frequency analysis from equally distributed mapping sites in the RA. Short lines of ablation lesions were aimed at the conduction channels between the lines of block, crista terminalis gaps, and the cavotricuspid isthmus, resulting in bidirectional block. AF was eliminated in 11 (85%) of 13 patients, and those 11 patients with acute success were free of AF without any antiarrhythmic drugs during the long-term follow-up period (16±6 months). Conclusions— RA ablation still can cure selected patients with PAF. Linear ablation of the RA substrate guided by the electrophysiological characteristics of RA-AF is an effective approach for treating this specific group of patients with AF.

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…The first identification and targeted ablation of rotational activity with fibrillatory activities was reported in 2005, using the noncontact mapping technique by Lin et al 562 The next system that was developed for clinical use employed two 64-pole basket catheters to obtain simultaneous unipolar endocardial electrograms from 128 locations in both atria of patients undergoing AF ablation. 563 A computational mapping system (Rhythm-View, Topera, Inc.) was used to process the electrograms and generate activation movies of the atrial electrical activity.…”

Driver Domains in Persistent Atrial Fibrillation

“…Localized drivers are difficult to detect in persistent AF with conventional techniques because of sequential temporospatial mapping, lack of specificity of complex atrial electrograms, intermittent firing, and spatial meandering. [7][8][9] Wide-field mapping tools have been used to capture these sources with the use of balloon, multispline probes 5,[10][11][12][13][14] or electrode arrays enveloping the torso. [15][16][17][18] Recent developments have allowed biatrial AF mapping using activation or phase-based analysis of body surface potentials.…”

Linear Catheter Ablation of the Right Atrium for Rapid Atrial Pacing-Induced Sustained Atrial Fibrillation in Dogs

“…5) Furthermore, linear ablation of the RA guided by the electrophysiologic characteristics of paroxysmal RA-AF is an effective approach for treating certain patients with AF. 6) The creation of linear lesions in the RA along the intercaval posterior line and intercaval septal line combined with electrical disconnection of the SVC has resulted in significantly higher success rates than with LA and cavotricuspid ablation alone.…”

“…5) Furthermore, linear ablation of the RA guided by the electrophysiologic characteristics of paroxysmal RA-AF is an effective approach for treating certain patients with AF. 6) Ablation in the RA to create linear lesions along the intercaval posterior line and intercaval septal line and electrical disconnection of the superior vena cava (SVC) have a substantially higher rate of success than that of LA and cavotricuspid ablation alone. 7) In a canine model of RA pacing-induced sustained AF, we used 3 different catheter systems to examine whether RA linear lesions can be created and then assess the effects of RA linear lesions on the chronic AF.…”