3D electroanatomical mapping is less sensitive to atrial remodeling in estimation of true left atrial volume than echocardiography

Changes in LA volume and diameter correlate with mechanisms of recurrence after paroxysmal AF ablation

Papathanasiou et al point out that the two different methods of LA volume and diameter measurement in our recent publication could limit the significance of the correlations we reported with PV reconnection and non-PV foci as mechanisms of post AF ablation recurrence. While we acknowledge the lack of statistically significant correlations of smaller echo derived LA diameter with PV reconnection or of a larger angiographic LA volume with non-PV foci, the congruent confidence intervals of this correlation suggest a statistical trend. Non-uniform LA dimensional changes as an expression of structural remodelling may also be a possible explanation. Published data indicates that angiographic LA volumes consistently exhibit a positive bias compared to echocardiographic volumes but do provide intra-procedural measurements better correlating with gold standard techniques like CT or MRI. Finally we agree with Papathanasiou et al that dynamic changes in LA dimensions likely correlate with early and late mechanisms of recurrence and merit prospective studies.

Voltage-guided ablation in persistent atrial fibrillation-favorable 1-year outcome and predictors

INTRODUCTION

Pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF) has a low success rate. A newer ablation concept targets left atrial (LA) low voltage zones (LVZ) which correlate with fibrosis and predict recurrence after PVI. We aimed to determine the success of combined PVI- and LVZ-guided ablation and to identify the predictors for LVZ and for ablation success.

METHODS AND RESULTS

A total of 119 consecutive patients who underwent their first ablation procedure due to persistent AF were included. After acquisition of a high-resolution LA voltage map, PVI- and LVZ-guided ablation were performed. Mean age was 69 ± 8 years, 53% were men, and 8% had longstanding persistent AF. We found LVZ in 55% of patients. Twelve-month freedom from recurrences off drugs was 69%. The only independent predictor for recurrence was the existence of LVZ (OR 4.2, 95% CI 1.54-11.41, p = 0.005). Existence of LVZ was predicted positively by age ≥ 67 years (OR 4.4, 95% CI 1.4-13.7, p = 0.011), LA volume index ≥ 68 ml/m² (OR 3.9, 95% CI 1.4-10.5, p = 0.008), and GFR ≤ 85 ml/min/1.73 m² (OR 12.5, 95% CI 2.0-76.6, p = 0.006). BMI ≥ 26 kg/m² (OR 0.06, 95% CI 0.01-0.30, p = 0.001) was a negative predictor of LVZ.

CONCLUSION

LVZ-guided ablation in combination with PVI results in comparably high success rates. However, the existence of LVZ remains the strongest predictor of ablation success.