Endoscopic transthoracic sympathicotomy affects the autonomic modulation of heart rate in patients with palmar hyperhidrosis

Background. Palmar hyperhidrosis has been associated with an increased acti vity of the sympathetic nervous system. The objective of this study was to assess the immediate and long-term effects of endoscopic transthoracic symp athicotomy on the autonomic modulation of the heart rate in patients with p almar hyperhidrosis. Methods. Power spectrum analysis of heart rate variability in the lying pos ition and after passive tilt to the upright position was performed in thirt een patients the day before and after sympathicotomy. A follow-up recording was performed in ten patients approximately six months later. Recordings f rom 26 healthy subjects were used as a reference group. Findings. The patients had a tendency to higher power of the low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; above 0.15 Hz) components than c ontrols in the upright position. After sympathicotomy LF power was reduced, but HF power was unchanged. At follow-up LF power remained at a lower leve l, but now HF power was reduced. Interpretation. Patients with palmar hyperhidrosis have a sympathetic overa ctivity but also a compensatory high parasympathetic activity. Sympathicoto my results in an initial sympathovagal imbalance with a parasympathetic pre dominance, which is restored on a long-term basis.