In the head-up tilt study, R–R intervals significantly increased after the surgery in the head-up tilt positions (P<0.05),> difference in the supine position. There is no significant difference in QTc and Twa before and after the surgery, both in the supine and the head-up tilt positions. There was no significant difference in the LF or HF before and after surgery, either in the supine position or the head-up tilt positions. In the LF/HF, there was no significant difference before and after surgery in the supine position. However, the LF/HF in the head-up tilt positions was significantly decreased after surgery (P<0.05).> suppression of ETS was recognized more obviously under the steeper head-up tilt positions. Conclusions: 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. However, the response to sympathetic stimulation was suppressed after the surgery.
Eur J Cardiothorac Surg 1999;15:194-198
Eur J Cardiothorac Surg 1999;15:194-198