Paroxysmal Atrial Fibrillation Maintained by Nonpulmonary Vein Sources Can Be Predicted by Dominant Frequency Analysis of Atriopulmonary Electrograms

INTRODUCTION: Increasing evidence suggests that high-frequency excitation in the pulmonary vein (PV) plays a dominant role in the maintenance of paroxysmal atrial fibrillation (AF). However, in a certain population of patients, AF remains inducible after PV isolation (PVI). We sought to clarify whether dominant frequency (DF) analysis of atriopulmonary electrograms can predict paroxysmal AF maintained by non-PV sources. METHODS AND RESULTS: Sixty-one patients with paroxysmal AF (aged 59 +/- 12 years) were studied. Before PVI, bipolar electrograms during AF were recorded simultaneously from three PV ostia, the coronary sinus (CS), and the septum and free wall of the right atrium (RA). DF was obtained by fast Fourier transform (FFT) analysis. AF was rendered noninducible after PVI in 39 of the 61 patients (noninducible group), but was still inducible in the remaining 22 (inducible group). Among the six recording sites, the highest DF was documented in the PV in all of the patients in the noninducible group; the maximum DF among the three PVs (PV-DF(max)) was higher than that among the CS and two RA sites (atrial DF(max); 7.2 +/- 1.0 Hz vs 5.8 +/- 0.7 Hz, P < 0.0001). In contrast, the highest DF was documented in the CS or RA in 45.5% of the patients in the inducible group; PV-DF(max) was comparable with atrial DF(max) (6.6 +/- 0.8 Hz vs 6.6 +/- 0.6 Hz). AF inducibility after PVI was predicted by a PV-to-atrial DF(max) gradient of <0.5 Hz, with a sensitivity of 90.9% and a specificity of 89.7%. CONCLUSION: Paroxysmal AF maintained by non-PV sources can be predicted by the PV-to-atrial DF gradient.