Longitudinal follow-up of cardiac vagal activity in individuals undergoing endoscopic thoracic sympathectomy

OBJECTIVE: To conduct a longitudinal investigation of cardiac vagal activity (CVA) by measuring resting HR and calculating the cardiac vagal index (CVI) in individuals undergoing sympathectomy for the treatment of primary hyperhidrosis. METHODS: This was a descriptive longitudinal study involving 22 patients, 13 of whom were female. The mean age was 22.5 ± 8.8 years. The palms, soles, and axillae were the most commonly affected sites. Resting HR was measured by an electrocardiogram performed 20 min before the 4-second exercise test (4sET), which was used in order to evaluate CVA at three different time points: before surgery, one month after surgery, and four years after surgery. RESULTS: Resting HR (expressed as mean ± SE) was found to have decreased significantly at 1 month after surgery (73.1 ± 1.6 bpm before surgery vs. 69.7 ± 1.2 bpm at one month after surgery; p = 0.01). However, the HR values obtained at four years after surgery tended to be similar to those obtained before surgery (p = 0.31). The CVI (expressed as mean ± SE) was found to have increased significantly at one month after surgery (1.44 ± 0.04 before surgery vs. 1.53 ± 0.03 at one month after surgery; p = 0.02). However, the CVI obtained at four years after surgery tended to be similar to that obtained before surgery (p = 0.10). CONCLUSIONS: At one month after sympathectomy for primary hyperhidrosis, patients present with changes in resting HR and CVA, both of which tend to return to baseline at four years after surgery.