Background: Spectral analysis of the left atrium can identify high dominant frequency (DF) sites, which might play a role in the perpetuation of atrial fibrillation (AF). Furthermore, the role of the cardiac autonomic nervous system (CANS) in the genesis of AF has been demonstrated. The relationship between CANS and the high-DF sites (AF nest) was the aim of the investigation.
Methods and results: In 12 dogs, high frequency stimulation was applied to locate 4 major left atrial (LA) ganglionated plexi (GPs). An Ensite Array and a mapping catheter were delivered into the left atrium for electroanatomical mapping. During sinus rhythm, spectral analysis was performed on the bipolar electrograms in the left atrium before and after epicardial GP ablation. The majority of AF nests were close to the GPs (52±18% of total AF nests). After GP ablation, the mean LA DF values decreased from 54±7Hz to 49±4Hz (P=0.023), and DF values of the AF nest decreased from 93±2Hz to 87±4Hz (P=0.001). Most of the previous AF nest sites close to the GPs disappeared (85±23%). The surface area of the AF nest decreased from 9±5cm(2) to 3±2cm(2) (P=0.001).
Conclusions: Catheter ablation of the GP decreased the DF values, AF nest areas and diminished the number of AF nests; particularly those close to the GPs, indicating that the CANS might play an important role in the mechanism of the AF nest.