Predictors of recurrence of atrial tachyarrhythmias after pulmonary vein isolation by functional and structural mapping of nonparoxysmal atrial fibrillation

Background: This study aimed to evaluate the predictors of recurrence of atrial tachyarrhythmias by structural and functional mapping: voltage, dominant frequency (DF), and rotor mapping after a pulmonary vein isolation (PVI) in nonparoxysmal atrial fibrillation (AF) patients. Methods: A total of 66 nonparoxysmal AF patients were prospectively investigated. After the PVI, an online real-time phase mapping system was used to detect the location of rotors with critical nonpassively activated ratios (%NPs) of ≧50% in each left atrial (LA) segment, and high-DFs of ≧7 Hz were simultaneously mapped. After restoring sinus rhythm, low-voltage areas (LVAs < 0.5 mV) were mapped using the Advisor HD grid catheter (HDG). Results: Sixty-four of 66 (97%) AF patients had minimum to mild LVAs regardless of an enlarged LAD and LA volume (45 ± 6.0 mm and 141 ± 29 ml). There were no significant differences in the max and mean DF values and %NPs between the patients with and without recurrent atrial tachyarrhythmias. However, there was a significant difference in the LVA/LA surface area between the patients with and without recurrent atrial tachyarrhythmias (p =.004). Atrial tachyarrhythmia freedom was significantly greater in those with LVAs of ≤3.3% than in those >3.3% after one procedure over 11.6 ± 0.8 months of follow-up (77.1% vs. 33.3%, p <.001). In a multivariate analysis, the LVA/LA surface area after the PVI (HR 1.079; CI, 1.025–1.135, p =.003) was an independent predictor of AF recurrence. Conclusions: The predictor of atrial tachyarrhythmia recurrence after the PVI was LVAs rather than DFs and rotors in nonparoxysmal AF patients.