A low fibrillatory wave amplitude predicts sinus node dysfunction after catheter ablation in patients with persistent atrial fibrillation.

BACKGROUND: Concealed sinus node dysfunction (SND) may become manifest after restoration of sinus rhythm by ablation in patients with persistent atrial fibrillation (AF). The purpose of this study was to investigate the predictors of SND after catheter ablation of persistent AF.

METHODS: Two hundred two consecutive patients who underwent ablation for persistent AF were enrolled. Ipsilateral pulmonary vein isolation followed by, if necessary, electrical cardioversion were performed in all patients. SND was defined when temporary and/or permanent pacemakers were needed due to sinus bradycardia after ablation.

RESULTS: SND developed in 12 (5.9 %) patients. There was no difference between the patients with and without SND in terms of the age (with SND, 67 ± 9 and without, 66 ± 10 years old, P = 0.599) and sex (male; 58 vs. 79 %, P = 0.186). However, the patients with SND had a lower amplitude of the fibrillatory waves (0.115 ± 0.086 vs. 0.176 ± 0.077 mV, P = 0.009) and larger left atrial volume index (LAVI; 66 ± 31 vs. 34 ± 13, P = 0.007) than those without. A receiver operating characteristic curve identified a fibrillatory wave amplitude of 0.145 mV (AUC = 0.742; sensitivity = 65 %; specificity = 83 %) and LAVI of 47.5 ml/m(2) (AUC = 0.837; sensitivity = 82 %; specificity = 87 %) as the optimal cutoff values for predicting SND. A multivariate analysis revealed that the amplitude of the fibrillatory waves (odds ratio = 0.84 for 0.010 mV increase, 95 % CI = 0.71-0.98, P = 0.031) and LAVI (odds ratio = 1.08 for 1.0 cm(3)/m(2) increase, 95 % CI = 1.04-1.12, P < 0.001) were independent risk factors for SND.

CONCLUSIONS: A low amplitude of the fibrillatory waves and a large LAVI were predictors of SND after restoration of sinus rhythm by ablation in patients with persistent AF.