Quantitative evaluation of ECG components of workers exposed to carbon disulfide.

The components of electrocardiograms (ECG) of 253 workers exposed to carbon disulfide (CDS) and those of 99 controls were quantitatively measured and evaluated. ECG of the exposed workers showed a statistically significant higher prevalence of ECG pathological changes, higher P amplitude and Macruz index, longer P duration, longer both crude and corrected Q-T intervals and R-R intervals and shorter P-R segments and QRS intervals than that of the controls. On the other hand, P-R intervals and heart rates of the two groups were not significantly different. Among both the the exposed and control groups, values of P duration were significantly negatively correlated with that of P-R segment: r = -0.216 and -0.132, respectively, p greater than 0.05. Values of the ECG components were not related to duration of exposure to CDS. Moreover, no significant difference was observed between duration of exposure of the exposed workers with and of those without pathological ECG changes. The method used in our study may be useful in evaluating the ECG of exposed workers before the appearance of the known pathological abnormalities.