Background: A < 20 ms increase in the interval between cavo-tricuspid isthmus (CTI) double potentials during incremental pacing (IP) is a highly specific marker differentiating functional from complete CTI block during typical flutter (AFL) ablation. Long-term effects of IP remain unclear. We aimed to assess the impact of IP in reducing AFL recurrences after CTI ablation.
Methods: One hundred and thirty-four patients (age 67 ± 13 years, 78% males) undergoing successful CTI ablation were included and divided into 2 groups: Group 1 (n = 68), in which ablation was performed before the IP maneuver was incorporated, with CTI block confirmed by at least 1 non-local and 1 local electrogram-based previously established criteria; and Group 2 (n = 66), in which IP maneuver was used to confirm complete CTI block.
Results: No intergroup differences were noted in baseline characteristics, ablation settings and fluoroscopy/radiofrequency times. Long-term AFL recurrences were observed in 14 out of 134 patients (10.4%), and were more common in Group 1 (19%, vs 1.5% among Group 2 patients, p < 0,001). Despite a longer follow-up period among the former group (1603 ± 734 vs. 964 ± 289 days, respectively), the adjusted AFL recurrence rate was still higher among Group 1 patients (4.3%/year vs. 0.6%/year, p < 0,001). Cox-regression analysis confirmed inclusion in Group 1 as the only predictor of AFL recurrences (HR = 8.2, CI 1.04-64.7, p = 0.046).
Conclusions: The addition of the IP maneuver for the diagnosis of complete CTI block reduces AFL long-term recurrences after ablation.
Keywords: Ablation; Cavo-tricuspid isthmus; Complete block; Incremental pacing; Typical flutter.
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