Maximum electrogram-guided ablation of cavotricuspid isthmus-dependent atrial flutter.

Aims: To verify and re-emphasise the efficacy of the max electrogram-guided approach for ablation of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL).

Methods: Consecutive patients were alternatively assigned to receive either conventional linear radio-frequency (RF) ablation between the tricuspid annulus and inferior vena cava (the linear approach) or RF ablation at sites with the highest electrograms (the max electrogram-guided approach). Sustained, bi-directional CTI block was the endpoint. Procedure parameters and follow-up data were obtained.

Results: In total, 80 patients were included, 40 each for the linear approach and the max electrogram-guided approach. To achieve sustained bi-directional CTI block, the linear approach needed 841 ± 594 sec or 14.0 ± 9.9 RF applications, with total fluoroscopy time of 18.6 ± 9.4 min and total procedure time of 152 ± 58 min, as compared to the max electrogram-guided approach which needed 350 ± 319 sec (p < 0.0001) or 5.8 ± 5.3 RF applications (p < 0.0001), with total fluoroscopy time of 14.8 ± 6.0 min (p < 0.05) and total procedure time of 111 ± 36 min (p < 0.0005). The CTI block was obtained with 3 or less RF applications in 18 patients in the max electrogram-guided group (45%), but only in 2 patients in the linear ablation group (5%). During follow-up of 28 ± 14 months, recurrence cases were 2 in the linear and 1 in the max electrogram-guided group (NS).

Conclusion: During ablation of AFL, directly targeting muscle bundles in the CTI as guided by the highest electrograms is more efficient than making a linear lesion across the entire CTI, since using the former approach needed less RF application, shorter fluoroscopy and procedure times than using the latter. The max electrogram-guided approach may be recommended for routine clinical use to replace the conventional linear ablation approach.