Vagal denervation and reinnervation after ablation of ganglionated plexi.
OBJECTIVE
Surgical ablation of ganglionated plexi has been proposed to increase efficacy of surgery for atrial fibrillation. This experimental canine study examined electrophysiologic attenuation and recovery of atrial vagal effects after ganglionated plexi ablation alone or with standard surgical lesion sets for atrial fibrillation.


METHODS
Dogs were divided into 3 groups: group 1 (n = 6) had focal ablation of the 4 major epicardial ganglionated plexi fat pads, group 2 (n = 6) had pulmonary vein isolation with ablation, and group 3 (n = 6) had posterior left atrial isolation with ablation. All fat pads were ablated. Sinus and atrioventricular interval changes during bilateral vagosympathetic trunk stimulation were examined before and both immediately and 4 weeks after ablation. Vagally induced effective refractory period changes and mean QRST area changes (index of local innervation) were examined in 5 atrial regions.


RESULTS
Sinus and atrioventricular interval changes and heart rate variability decreased immediately after ablation, but only sinus interval changes were restored significantly after 4 weeks in all groups. Ablation-modified vagal effects on effective refractory period or QRST area changed heterogeneously in groups 1 and 2. In group 3, regional vagal effects were attenuated extensively postablation in both atria. Posterior left atrial isolation with ablation incrementally denervated the atria. In the long term, vagal stimulation increased QRST area changes relative to control values in all groups. Heart rate variability was also assessed.


CONCLUSIONS
Ganglionated plexi ablation significantly reduced atrial vagal innervation. Restoration of vagal effects at 4 weeks suggests early atrial reinnervation.
Sakamoto
Shun-ichiro
S
Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St Louis, MO 63110, USA.
Schuessler
Richard B
RB
Lee
Anson M
AM
Aziz
Abdulhameed
A
Lall
Shelly C
SC
Damiano
Ralph J
RJ
D000273:Adipose Tissue / Q000601:surgery; D000818:Animals; D001281:Atrial Fibrillation / Q000601:surgery; D017115:Catheter Ablation; D004285:Dogs; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005725:Ganglia, Autonomic / Q000503:physiopathology* / Q000601:surgery; D006325:Heart Atria / Q000294:innervation* / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006339:Heart Rate / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D011667:Pulmonary Veins / Q000601:surgery; D012849:Sinoatrial Node / Q000502:physiology