Slow whole left atrial conduction velocity after pulmonary vein
isolation predicts atrial fibrillation recurrence
Abstract
Background: Atrial conduction velocity may represent atrial fibrillation
(AF) substrate after pulmonary vein isolation (PVI). To elucidate the
association between whole left atrial conduction velocity (LACV) and AF
recurrence after PVI. Methods and Results: This observational study
enrolled 279 patients who underwent PVI alone as an initial AF ablation
procedure. After PVI, the left atrium was mapped with a 20-pole
multielectrode in conjunction with the CARTO3 system during 100-ppm
right atrial pacing. Left atrial conduction distance and conduction time
were calculated from the start to the end of the propagation wave front
in the left atrium. LACVs on the anterior and posterior routes were
calculated as conduction distance divided by conduction time. Anterior
and posterior LACVs were slower in patients with AF recurrence than in
those without (anterior, 0.79 [0.71, 0.86] vs. 0.96 [0.90,
1.06], p < 0.001; posterior, 0.99 [0.89, 1.14] vs. 1.10
[1.00, 1.29], p < 0.001). AF recurrence was best predicted
by anterior LACV with a cut-off value of 0.87 m/s (sensitivity 87%,
specificity 81%, and predictive accuracy 84%). Multivariate analysis
demonstrated that a slow anterior LACV < 0.87 m/s was an
independent predictor of AF recurrence with an adjusted hazard ratio of
11.8 (6.36 – 22.0). Patients with anterior low-voltage areas
demonstrated slower anterior LACV than those without low-voltage areas
(0.89 [0.71, 1.00] vs. 0.94 [0.87, 1.05], p < 0.001).
Conclusion: A slow LACV in the entire left atrium was an excellent
predictor of AF recurrence after PVI, suggesting the necessity of
additional ablations.