Heart rate variability as a potential diagnostic tool to predict compensatory hyperhidrosis after sympathectomy in patients with primary focal hyperhidrosis

Primary focal hyperhidrosis (PFH) is associated with autonomic nervous activity, and studies investigating this association in patients with PFH are very important. Heart rate variability (HRV) is a simple and noninvasive electrocardiographic test showing activity and balance in the autonomic nervous system, which consists of sympathetic and parasympathetic components. The aims of this study are to investigate associations between autonomic nervous activity and hyperhidrosis characteristics using HRV and to investigate the association between HRV findings and compensatory hyperhidrosis (CH) after sympathectomy. From March 2017 to March 2020, 105 subjects with PFH who underwent preoperative HRV tests and sympathectomy were analyzed. All subjects underwent bilateral thoracoscopic sympathectomy. T2 sympathectomy was conducted for craniofacial hyperhidrosis, and T3 sympathectomy was conducted for palmar hyperhidrosis. The following HRV parameters chosen to investigate the association between hyperhidrosis and autonomic nervous activity were measured by time and frequency domain spectral analysis: (I) time domain: standard deviation of normal-to-normal interval (SDNN) and square root of mean squared differences of successive normal-to-normal intervals (RMSSD), (II) frequency domain: total power (TP) of power spectral density, very low frequency (VLF), low frequency (LF), and high frequency (HF). HRV parameters were analyzed according to hyperhidrosis type (craniofacial vs. palmar type), sweat reduction, and CH after sympathectomy. In addition, the independent HRV parameters influencing CH after sympathectomy were investigated with multivariate analysis. Craniofacial hyperhidrosis was significantly more prevalent in the old age group (P