Effect of conscious sedation and deep sedation on the vagal response characteristics during ganglionated plexus ablation.

Introduction: We aimed to determine the effects of conscious and deep sedation on vagal response (VR) characteristics during ganglionated plexus (GP) ablation.

Methods: Forty consecutive patients undergoing GP ablation for vasovagal syncope were divided to receive conscious sedation with midazolam (Group 1, n = 29) or deep sedation with the midazolam-propofol combination (Group 2, n = 11). VR was defined on three levels. R-R interval increase of >50% (Level 1); R-R interval increase of 20%-50% (Level 2); and R-R interval increase of <20% (Level 3).

Results: The ratio of Level 1 VR during ablation on left superior and inferior GPs was significantly lower in Group 2 (p < .0001 and p = .034, respectively). Once the cut-off for VR was decreased to Level 2, the ratio of (+) VR was similar between groups during ablation of left-sided GPs. Positive VR in any level was lower than 20% during ablation of right-sided GPs.

Conclusions: The autonomic tone might be affected in different ways by the level or type of intravenous sedation. Awareness of anesthesia-related differences may be important if GP ablation will be performed by using VR characteristics during ablation.