Heart-rate variability of carbon disulfide-poisoned subjects in Korea

Objectives: Mass poisoning by carbon disulfide (CS2) occurred in a viscose-rayon factory in Korea. Including 38 who had died, 830 employees were diagnosed as CS2 poisoned. We evaluated the heart-rate variability (HRV) among CS2-poisoned subjects, to discover whether CS2 may affect HRV and whether its toxic effect persists after exposure has ceased. Methods: The case group comprised 71 retired male workers with CS2 poisoning. The control group comprised 127 public officials of the same age-range who had no history of organic-solvent exposure and cardiovascular diseases. Information on individual age, height, weight, cigarette smoking, alcohol drinking, regular exercise, medical and occupational history, and ECG recordings of the two groups were collected through medical examination and self-administered questionnaire. Time (maximum, average, minimum RR interval) and frequency domain measures [low (LF), high (HF), and total power spectrum (TPS)] of the two groups were analyzed. Results: In univariate analysis, time domain measures of the two groups did not differ significantly, while frequency domain measures in the case group was significantly lower than in the control group except for HF power. In multivariate analysis, previous history of CS2 poisoning was inversely related to all frequency domain measures and significantly affected LF power. Conclusions: This study suggests that CS2 may cause heart-rate impairment and its toxic effect persists after exposure has ceased. Based on this study, HRV measurement can be considered as a useful tool to assess toxic effects Of CS2 both in current and retired workers.