Reduced atrial conduction velocity is associated with the recurrence of atrial fibrillation after catheter ablation

Regional left atrial conduction velocity in the anterior wall is associated with clinical recurrence of atrial fibrillation after catheter ablation: efficacy in combination with the ipsilateral low voltage area

Background

Left atrial (LA) conduction velocity (CV) is an electrical remodeling parameter of atrial fibrillation (AF) substrate. However, the pathophysiological substrate of LA-CV and its impact on outcomes after catheter ablation for AF have not been well evaluated.

Methods

We retrospectively evaluated 119 patients with AF who underwent catheter ablation and electroanatomical mapping during sinus rhythm. To measure regional LA-CV, we took triplet sites (A, B, and C) on the activation map and calculated the magnitude of the matched orthogonal projection vector between vector-AB and vector-AC, indicating two-dimensional CV. The median of the LA-CVs from four triad sites in both the anterior and posterior walls was set as the ‘model LA-CV’. We evaluated the impact of the model LA-CV on recurrence after ablation and relationship between the model LA-CV and LA-low voltage area (LVA) of < 0.5 mV.

Results

During the 12-month follow-up, 29 patients experienced recurrence. The LA-CV model was significantly correlated with ipsilateral LVA. The lower anterior model LA-CV was significantly associated with recurrence, with the cut-off value of 0.80 m/s having a sensitivity of 72% and specificity of 67%. Multivariable analysis revealed that the anterior model LA-CV (hazard ratio, 0.09; 95% confidence interval, 0.01–0.94; p = 0.043) and anterior LA-LVA (hazard ratio, 1.06; 95% confidence interval, 1.00–1.11; p = 0.033) were independently associated with AF recurrence. The anterior LA-LVA was mildly correlated with the anterior model LA-CV (r = -0.358; p < 0.001), and patients with both lower LA-CV and greater anterior LA-LVA based on each cut-off value had the worst prognosis. However, decreased LA-CV was more likely to be affected by the distribution pattern of the LVA rather than the total size of the LVA.

Conclusion

Decreased anterior LA-CV was a significant predictor of AF recurrence and was a useful electrical parameter in addition to LA-LVA for estimating AF arrhythmogenicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02881-6.

Evaluation of interatrial conduction pattern after pulmonary vein isolation using an ultrahigh-resolution electroanatomical mapping system

Interatrial conduction consists of various muscular bundles, including the Bachmann bundle. In this study, we investigated interatrial activation patterns using ultrahigh-resolution left atrial endocardial mapping. This study investigated 58 patients who underwent catheter ablation of atrial arrhythmia via an ultrahigh-resolution mapping system (Rhythmia) at our hospital from May 2020 to January 2021. Left atrial voltage maps and activation maps were acquired after the ablation procedure during right atrial appendage (RAA) pacing. We defined left atrial breakout sites (LABSs) as centrifugal activation patterns shown by the LUMIPOINT Activation Search Tool. The distance between each LABS in the left atrial anterior wall and the superior border of the interatrial septum (D_LABS-IAS) was measured on the shell of the electroanatomical map, and anterior LABSs were divided equally into roof- and septal-side groups. Fifty-three (91%) patients underwent cryoballoon pulmonary vein isolation. Ultrahigh-resolution left atrial mapping was successfully performed in all patients (6831 ± 2158 points). A total of 82 LABSs were identified in left atrial anterior wall; 34 patients had single LABS and 24 patients had dual LABSs. The mean D_LABS-IAS was 10.3 ± 9.6 mm. Seven patients also exhibited posterior LABS near the interatrial raphe below the right inferior pulmonary vein. Patients with a single roof-side LABS had significantly shorter left atrial activation times than those with a single septal-side LABS (81.6 ± 13.2 ms vs. 93.5 ± 13.7 ms, p < 0.05). Interatrial conduction patterns during RAA pacing varied between patients and affected the left atrial activation time.