Single Ectopy-Triggering Ganglionated Plexus Ablation Without Pulmonary Vein Isolation Prevents Atrial Fibrillation

Figure 1. 12-Lead Electrocardiogram A 12-lead electrocardiogram confirmed atrial fibrillation before the ablation procedure.

Figure 2. Initiation of PV Ectopy-Triggering Atrial Fibrillation From ET-GP Stimulation The ablation catheter (Mapd) was used to pace and deliver high-frequency stimulation (HFS). The pulmonary vein (PV) catheter was inserted into the left inferior PV. No recordings were obtained from the first 3 pulmonary vein channels because of poor tissue contact of PV poles 1 to 6 of the Lasso catheter. The first 2 artifacts are from pacing the left atrium at 10 V with atrial capture. The third and fourth artifacts are high-frequency stimulation (10-V, 35-Hz, 85-ms duration), delivered immediately after pacing from the ablation catheter (within the local atrial refractory period). After the first train of high-frequency stimulation, PV ectopy is triggered in the left inferior PV, with the earliest activation signals in PV 9 to 10 and PV 11 to 12. This led to atrial fibrillation, which terminated to sinus rhythm after 24 s. ET-GP = ectopy-triggering ganglionated plexus.

Figure 3. Ablation of ET-GP Leading to Acute Termination of AF (A) Posteroanterior (PA) view of left atrium demonstrating locations of high-frequency stimulation (HFS) testing (purple represents a negative high-frequency stimulation response with synchronized high-frequency stimulation, pink is a negative high-frequency stimulation response with continuous high-frequency stimulation, light green is ectopy-triggering ganglionated plexus [ET-GP] with synchronized high-frequency stimulation, and dark green is atrioventricular dissociating ganglionated plexus with continuous high-frequency stimulation). The adjacent electrograms show that the patient was in sinus bradycardia before ablation. The pulmonary vein (PV) catheter (Lasso, Biosense Webster, Irvine, California) was situated in the left inferior pulmonary vein (LIPV). Low-output pacing artifact was inadvertent. Ablation started over the ectopy-triggering ganglionated plexus site as depicted. The onset of radiofrequency (RF) immediately triggered left inferior pulmonary vein ectopy and atrial fibrillation (AF). (B) Posteroanterior view of the left atrium demonstrating the location of cluster radiofrequency ablation performed over the…

Figure 4. Synchronized HFS at Ablated ET-GP Inducing No Further AF After ablation of the ectopy-triggering ganglionated plexus (ET-GP) near left inferior pulmonary vein (LIPV), repeat synchronized high-frequency stimulation (HFS) was performed at the same ablated site. The pulmonary vein (PV) catheter remained in the left inferior pulmonary vein. The first 2 artifacts are from pacing the left atrium at high output, thus confirming atrial capture. Subsequently, synchronized high-frequency stimulation was performed; it did not trigger pulmonary vein ectopy or atrial fibrillation (AF) again. Abbreviations as in Figures 2 and 3.