Trigger-based mechanism of the persistence of atrial fibrillation and its impact on the efficacy of catheter ablation.

BACKGROUND

We investigated the possibility that a frequent trigger action might play a role in the development of persistent atrial fibrillation (PeAF) and the presence of a substrate.

METHODS AND RESULTS

In 263 consecutive patients who underwent catheter ablation (CA) for PeAF, electric cardioversion was performed at the beginning of the procedure to determine the presence or absence of an immediate recurrence of AF (IRAF). We defined an IRAF as a reproducible AF recurrence within 90 s after restoration of sinus rhythm by electric cardioversion. We performed a mean±SD of 1.3±0.5 sessions of CA, including pulmonary vein isolation and ablation of the premature atrial contractions that triggered the IRAF (IRAF triggers), and observed the patients for 17 (10-27) months. An IRAF was observed in 70 patients (27%), but we could not ablate the IRAF triggers in 16 (23%) of these IRAF patients. The recurrence rate of PeAF was higher in patients with an unsuccessful IRAF trigger ablation than in those with successful IRAF trigger ablation (63% versus 11%; P<0.001). A multivariable analysis also revealed that an unsuccessful IRAF trigger ablation was 1 of the independent predictors of recurrent PeAF (odds ratio, 10.9; 95% CI, 3.4-36.7).

CONCLUSIONS

In the PeAF patients with an IRAF, successful elimination of the IRAF triggers, in addition to pulmonary vein isolation, resulted in a successful CA. These results imply that such triggers play a major role in the AF persistence in these PeAF patients.