We evaluated risk of bradycardia after endoscopic electrocautery of the upper thoracic sympathetic ganglia (ETS). Enrolled in this study were 24 patients. Bradycardia, defined as heart rate below 50 beats per min continuing for more than 5 min, was found in 12 patients (50%). All patients were divided into two groups; bradycardia group and non-bradycardia group. Age, sex, region of electrocautery, fentanyl dosage, and operation time were not different between the two groups. Power spectral analysis of heart rate variability revealed that sympathetic activity decreased after ETS. Multivariate analysis indicates that postoperative-minimal heart rate depends upon preoperative heart rate at rest. We conclude that careful monitoring after ETS is necessary in a patient with heart rate below 60 bpm preoperatively.
http://www.ncbi.nlm.nih.gov/pubmed/10885235