The Double-Isolation Procedure Provides Superior Outcomes than the Box Lesion Set in Patients with Persistent AF
Claudio Muneretto, Gianluigi Bisleri, Fabrizio Rosati, Luca Bontempi, Antonio Curnis.
University of Brescia Medical School, Brescia, Italy.
OBJECTIVE: The box lesion set has proved to be an effective ablation pattern in paroxysmal atrial fibrillation(AF), albeit a more extensive lesion set may be required in patients with persistent AF in order to further reduce the risk of potential reentrant circuits.
METHODS: Fifty-one (51) patients with persistent stand-lone atrial fibrillation underwent a surgical, closed-chest pulmonary veins isolation. In thirty-one patients (Group A, N=31) the ablation was performed by means of a “box” lesion set in the left atrium and additional lines in right atrium (Figure 1: intercaval line, line from the transverse sinus and from the oblique sinus to the RAA); in the remaining patients (Group B, n=20) only the box lesion was performed. No significant differences were observed between the two group in terms of age (Group A=64.4±10 vs Group B=63.4±9.4 years, p=NS), median AF duration (Group A= 35 vs Group B= 39 months, p=NS), LA antero-posterior diameter (Group A= 46.9±6 vs Group B=47±6.3 mm, p=NS). Rhythm outcomes were assessed by means of an implantable loop recorder and Holter monitoring.
RESULTS: The minimally invasive procedures could be completed in either groups: in particular, right atrial lesions could be easily added to the box lesion without any intraoperative complications. At a median follow-up of 20 months, sinus rhythm restoration was achieved in 27/31 pts (87.1%) in patients receiving the double isolation procedure while only 60% of patients (12/20) in Group B (box lesion set) were in sinus rhythm.
CONCLUSIONS: The double isolation procedure proved to be a safe and feasible technique for persistent AF via a minimally invasive approach. At a median follow-up of 20 months, it was associated with incremental benefits in terms of sinus rhythm restoration compared to the box lesion set alone.
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