Original Article http://dx.doi.org/10.3349/ymj.2012.53.6.1081 pISSN: 0513-5796, eISSN: 1976-2437 Yonsei Med J 53(6):1081-1084, 2012 The Effects of Thoracic Sympathotomy on Heart Rate Variability in Patients with Palmar Hyperhidrosis Tong-yuan Zhang, Long Wang, and Jin-jin Xu Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China. Received: April 4, 2012 Revised: May 16, 2012 Accepted: June 11, 2012 Corresponding author: Dr. Long Wang, Department of Anesthesiology, Renmin Hospital of Wuhan University, Jie Fang Road 238#, WuHan, HuBei, China. Tel: 0086-2788041911-81026, Fax: 0086-2788042922 E-mail: wanglongwhu@163.com ∙ The authors have no financial conflicts of interest. Purpose: To observe the evolution of heart rate variability (HRV) in patients with palmar hyperhidrosis before and after endoscopic thoracic sympathotomy and to evaluate the effects of the surgery on the autonomic nervous system. Materials and Methods: Endoscopic thoracic sympathotomy was performed on 20 patients with palmar hyperhidrosis. The thoracic sympathetic chain at the level of the third to fourth rib (R3-R4) was transected, but the ganglia were left in position without removal. A slightly larger ramus, in comparison to the other rami, that arose later- ally from the sympathetic chain was interrupted to achieve adequate sympathetic denervation of the upper extremity. Before and on the day after the surgery, 24- hour Holter Electrocardiograph was performed, obtaining time domain and fre- quency domain parameters. Results: Compared with preoperative variables, there was a significant increase in the number of adjacent normal R wave to R wave (R- R) intervals that differed by more than 50 ms, as percent of the total number of normal RR intervals (pNN50); root mean square difference, the square root of the mean of the sum of squared differences between adjacent normal RR intervals over the entire 24-hour recording; standard deviation of the average normal RR in- terval for all 5-minute segments of a 24-hour recording (SDANN) after thoracic sympathotomy. Low frequencies (LF, 0.04 to 0.15 Hz) decreased significantly. There was no statistical difference in high frequencies (HF, 0.15 to 0.40 Hz), LF/ HF ratio (LF/HF), or standard deviation for all normal RR intervals for the entire 24-h recording (SDNN) before and after thoracic sympathotomy. Conclusion: There was a significant improvement in HRV in patients with palmar hyperhidro- sis after thoracic sympathotomy. This may be attributable to an improvement auto- nomic nervous system balance and parasympathetic predominance in the early postoperative stage. Key Words: Sympathotomy, hyperhidrosis, heart rate, autonomic nervous system © Copyright: Yonsei University College of Medicine 2012 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non- Commercial License (http://creativecommons.org/ licenses/by-nc/3.0) which permits unrestricted non- commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION Palmar hyperhidrosis, a type of primary hyperhidrosis without a known etiology, is characterized by excessive sweating of the palms and often the armpits. It has been associated with dysfunction of the sympathetic nervous system.1 Ablation of Yonsei Med J http://www.eymj.org Volume 53 Number 6 November 2012 1081