Heart rate variability in workers exposed to carbon disulfide

It is assumed that the cardiovascular impairments resulting from CS2 exposure may be associated with some functional disturbances within the autonomic nervous system. We adopted the heart rate variability (HRV) analysis to investigate the sympathetic and parasympathetic functions of the autonomic nervous system in workers exposed to carbon disulfide. The studies were performed on 152 workers, aged 24-66, with the period of exposure ranging from 5-38 years and 93 age-matched, non-exposed, healthy individuals as the control group. The HRV analysis concerned time-domain (AVG R-R, SD R-R, modal, median, minimum and maximum values) and frequency-domain indices (power spectrum in the very low-VLF, low-LF and high-HF frequency bands) calculated using the fast Fourier transformation. In the exposed group, neurovegetative regulation impairments could be observed. They were expressed as increased heart rate at rest, reduced power spectrum: total (TPS) and within HF, LF and VLF frequency bands as well as the absence of the physiological dependence of HRV parameters on age. These abnormalities could be found even in the group of workers exposed to the lowest CS2 levels (0-10 mg/m3) and they concerned the VLF band. In workers under conditions of exposure to 10-18 mg/m3 the dysfunction of the autonomic control referred both to its sympathetic and parasympathetic part and was found to be more intense in workers exposed to the highest CS2 concentrations (over 18 mg/m3). In view of our findings we concluded that occupational exposure to carbon disulfide may bring about an impaired neurovegetative regulation of the cardiovascular function.