Influences of bilateral endoscopic transthoracic sympathicotomy on cardiacautonomic nervous activity

Objectives: Endoscopic transthoracic sympathicotomy (ETS) is a minimal inva sive procedure of thoracic sympathetic blockage. The purpose of this study was to evaluate cardiac autonomic nervous activity after ETS in order to co nfirm the reliability and safety of ETS. Methods: A series of electrophysio logical studies were performed before and 1 week after bilateral 2nd and 3r d thoracic sympathicotomy in 13 patients with primary palmar hyperhydrosis. Palmar perspiration was measured under sympathetic stress, and body surfac e mapping was recorded in a supine position. In the head-up tilt test of 0, 30, 60 and 90 degrees. corrected QT interval (QTc) and T wave amplitude (T wa) were assessed. The power spectral analysis of heart rate variability wa s processed to attain power values of the low-frequency (0.04-0.15 Hz), the high-frequency (0.15-0.40 Hz) and the low/high frequency ratio. Results: I n all patients, the perspiration response on the palm to sympathetic stimul ation was completely inhibited after ETS. Isointegral mapping revealed that ETS altered electroactivity on the heart. In the head-up tilt study, R-R i ntervals significantly increased after the surgery in the head-up tilt posi tions (P < 0.05), although there was no significant difference in the supin e position. There is no significant difference in QTc and Twa before and af ter the surgery, both in the supine and the head-up tilt positions. There w as no significant difference in the LF or HF before and after surgery, eith er in the supine position or the head-up tilt positions. In the LF/HF, ther e was as no significant difference before and after surgery in the supine p osition. However. the LF/HF in the head-up tilt positions was significantly decreased after surgery (P < 0.05). Sympathetic suppression of ETS was rec ognized more obviously under the steeper head-up tilt positions. Conclusion s: The influences on the cardiac autonomic nerve system of the ETS of upper thoracic sympathetic nerve were seen to be of a lesser degree at rest. How ever, the response to sympathetic stimulation was suppressed after the surg ery. (C) 1999 Elsevier Science B.V. All rights reserved.