Atrial Fibrillation - Mechanisms
Characterization of Complex Atrial Tachycardia in Patients With Previous Atrial Interventions Using High-Resolution Mapping

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Abstract

Objectives

This study systematically evaluated mechanisms of atrial tachycardia (AT) by using ultra-high-resolution mapping in a large cohort of patients.

Background

An incomplete understanding of the mechanism of AT is a major determinant of ablation failure.

Methods

Consecutive patients with ≥1 AT (excluding cavotricuspid isthmus–dependent flutter) were included. Mapping was performed with a 64-pole mapping catheter. The AT mechanism was defined based on activation mapping and confirmed by entrainment in selected cases.

Results

A total of 132 patients were included (60 ± 12 years; 31 [23%] female; 111 [84%] previous atrial fibrillation [AF] ablation; 5 [4%] previous left atriotomy). One hundred four (94%) of the 111 post–AF ablation AT patients had substrate-based ablation during the index AF ablation. A total of 214 ATs were mapped, with complete definition of the AT mechanism in 206 (96%). A total of 129 (60%) had anatomic macro–re-entry (circuit diameter 44.2 ± 9.6 mm), 57 (27%) had scar-related localized re-entry (circuit diameter 25.8 ± 12.2 mm), and 20 (9%) had focal AT. Fifty-eight (45%) patients had multiple ATs (27 [20%] dual-loop re-entry; 60 [43%] sequential AT) with complex and highly variable transitions between AT circuits. A total of 116 (90%) of 129 macro–re-entrant ATs, 56 (98%) of 57 localized AT, and 20 (100%) of 20 focal ATs terminated after radiofrequency ablation. After a mean follow-up of 13 ± 9 months, 57 (46%) patients experienced recurrence of AT.

Conclusions

Among patients with AT in the context of previous atrial interventions, particularly post–AF ablation patients, multiple complex AT circuits are common. Despite complete delineation of arrhythmia circuits using ultra-high-resolution mapping and high acute ablation success rates, long-term freedom from AT is modest.

Key Words

atrial fibrillation
atrial tachycardia
cardiac mapping
catheter ablation

Abbreviations and Acronyms

AF
atrial fibrillation
AT
atrial tachycardia
CFAE
complex fragmented atrial electrogram
CTI
cavotricuspid isthmus
ECG
electrocardiogram
ECGi
electrocardiographic imaging
EGM
electrogram
PVI
pulmonary vein isolation
RA
right atria
RF
radiofrequency

Cited by (0)

This study received financial support from the French Government as part of the “Investments of the Future” program managed by the National Research Agency (Grant reference ANR-10-IAHU-04). Drs. Derval, Denis, Sacher, and Jaïs have received modest consulting fees and speaking honoraria from Boston Scientific. Dr. Mahida has received speaking honoraria from Abbott and Boston Scientific. Dr. Jaïs has received a grant from BSCI; and has received lecture fees from Boston Scientific, Biosense Webster, and Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.

Drs. Derval and Takigawa contributed equally to this work and are joint first authors.