Tailored bi-atrial linear ablation guided by electrophysiological mapping for persistent atrial fibrillation

Abstract

Aim: To explore the safety and efficacy of a novel strategy (bi-atrial linear catheter ablation guided by electrophysiological mapping) for persistent atrial fibrillation (PeAF) treatment.

Methods: 83 patients with PeAF were enrolled for evaluation of ablation strategy. 43 patients were subjected to pulmonary vein isolation (PVI) strategy (PVI group). 40 patients were subjected to bi-atrial linear ablation strategy guided by electrophysiological mapping (PVI, left atrial BOX ablation, coronary sinus endocardial linear ablation, tailored left atrial anterior wall linear ablation, mitral isthmus linear ablation with necessary ethanol infusion into the vein of Marshall, right atrial posterior wall linear ablation and cavo-tricuspid isthmus ablation) (linear ablation group). Patients were followed up every 3 months.

Results: During a median follow-up of 12 (4-16) months, freedom from atrial fibrillation/atrial tachycardia recurrence was 87.5% in the linear ablation group and 65.1% in the PVI group (P < 0.01). A Cox regression multivariate analysis revealed that ablation strategy group (tailored bi-atrial linear ablation) (HR 0.33, 95% CI 0.12-0.91, P = 0.03) was the only independent predictor of recurrence.

Conclusion: Tailored bi-atrial linear ablation strategy guided by electrophysiological mapping resulted in improved outcomes without compromising safety for patients with PeAF.

Keywords: Catheter ablation; Electrophysiological mapping guidance; Linear ablation; Persistent atrial fibrillation.

Fig. 1

Illustrative summary of the tailored bi-atrial linear ablation strategy Following linear ablations and EIVOM if necessary, the atria have been compartmentalized and impulses are conducted (green arrows line from the SN) as shown. Red dots: PVI; Brown dots: Roof line and floor line for BOX; Yellow dots: CS endocardial ablation; Orange dots: LA anterior wall line; Black dots: MA isthmus line; Navy blue dots: Right atrial posterior wall line; Light blue dots: CTI line. AP, anteroposterior; AVN, atrioventricular node; CS, coronary sinus; CTI, Cavo-tricuspid isthmus; FO, fossa ovalis; IVC, inferior vena cava; LAA, left atrial appendage; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; MA, mitral annulus; PA, posteroanterior; RSPV, right superior pulmonary vein; RIPV, right inferior pulmonary vein; SN, sinus node; SVC, superior vena cava; TA, tricuspid annulus; VOM, vein of Marshall

Fig. 2

Workflow of the tailored linear ablation strategy

Fig. 3

Electrophysiological mapping-guided bi-atrial linear ablation strategy in one case A: Substrate of the atria and intracardiac electrocardiograms (IEGMs) before ablation, after PVI, after PVI and BOX ablation, after PVI with BOX and CS endocardial ablation. AF terminated and transformed into AFL related to MI after PVI, BOX and CS endocardial ablation B: Mutual transformation between MI-related AFL and AF during MI ablation. AF transformed into CTI-related AFL after MI ablation. AFL terminated and transformed into SR after CTI ablation C: Activation mapping during SR for revealing the earliest location via Bachmann bundle from the right atrium. LA anterior wall linear ablation below the earliest site according to the activation mapping. The second figure showed linear block by activation mapping during LAA pacing (the yellow star). Red arrows indicate the impulse conduction. The impulse was conducted to LAA via Bachmann bundle from the right atrium like the color variation showed on the atria (red→yellow→green→purple) according to activation mapping during SR after bi-atrial linear ablation in the third and fourth figure AP, anteroposterior; PA, posteroanterior

Fig. 4

Ablation catheter at endocardial area of CS (A), MI (B) and RA posterior wall (C) during the linear ablation strategy. LAO, left anterior oblique; RAO, right anterior oblique;

Fig. 5

EIVOM for MI block A: Mitral isthmus (MI) was not blocked after endocardial and epicardial ablation B: EIVOM was performed C: MI was blocked during EIVOM: Pentaray catheter was located at LAA. Pacing from LAA continuously proceed during EIVOM. The activation sequency of the CS was from CS-distal (CS 1,2) to CS-proximal (CS 9,10) at the beginning. When clockwise block of MI was achieved, activation sequency became from CS-proximal to CS-distal (red arrow) D: Counterclockwise block of MI was confirmed by pacing the CS-distal pole. The Pentaray catheter was located at LAA. LAA was activated later than CS-proximal EIVOM, Ethanol infusion into the vein of Marshall; LAA, left atrial appendage; MI, Mitral isthmus

Fig. 6

Freedom from recurrence of AF/atrial tachycardia in the linear ablation group and PVI group Kaplan-Meier curve showed that cumulative freedom from recurrence was higher in the linear ablation group (log-rank test, P = 0.01)