Localization of left atrial ganglionated plexi in patients with atrial fibrillation

The intrinsic cardiac autonomic nervous system (ICANS), which forms a neural network, has been shown to be a critical element responsible for the initiation and maintenance of atrial fibrillation (AF). We developed a technique to localize and ablate the ganglionated plexi (GP), which serves as the "integration centers" of the ICANS.

The four major atrial GP are localized by delivering high frequency stimulation (HFS; 20 Hz, 10-150 V, 1-10 ms pulse width) to atrial tissue where GP are presumed to be located. Sites showing a parasympathetic response, which is arbitrarily defined as > or =50% increase in mean R-R interval during AF, was assigned as a GP site. Radiofrequency current is then applied to that site to eliminate the parasympathetic response. All patients received ablation of the four major atrial GP, followed by pulmonary vein antrum ablation.

Our preliminary results showed that all the four major atrial GP can be identified in the vast majority of patients. The parasympathetic response can be eliminated by applying radiofrequency current. In the first 83 patients, the percent of patients free of symptomatic AF or atrial tachycardia after a single ablation procedure was 80% at 12 months and 86% at a mean follow-up of 22 months.

These results indicate additional benefits of GP ablation to PV antrum ablation and improvement with time, particularly > or = 12 months after ablation. We postulate that this late benefit may result from destruction of the autonomic neurons in the GP that cannot regenerate.