Temporal analysis of heart rate variability as a predictor of post traumatic stress disorder in road traffic accidents survivors.

Background: Road Traffic Accidents (RTA) are most probably the leading cause of post traumatic stress disorder (PTSD) in developed countries. The autonomic nervous system (ANS) disturbances, due to psychological trauma, are part of the pathophysiology of PTSD. The aim of the present study was to determine whether early heart rate variability (HRV) measurement, a biomarker of the ANS function, could act as a predictor of PTSD development after a RTA.

Methods: We prospectively investigated 35 survivors of RTA with both physical injury and psychological trauma. HRV data were obtained from 24-h Holter ECG monitoring, which was performed on the second day after the accident. Time domain analysis was applied to the inter-beat (RR) interval time series to calculate the various parameters of HRV. PTSD status was assessed 2 and 6 months after RTA.

Results: There was a global diminution of HRV measurements in the PTSD group at both 2 and 6 months. The variability index was the best predictor of PTSD with the area under the receiveroperating curve for discriminating PTSD at 6 months at 0.92 (95% CI: 0.785; 1.046). A cut-off at 2.19% yielded a sensitivity of 85.7% and a specificity of 81.8% for PTSD. Positive and negative predictive values were respectively 75% and 90%. However, initial heart rate (HR) data were relevant at 2 months but not at 6 months.

Conclusion: RTA survivors exhibiting lower parasympathetic modulation of HR, indexed by temporal analysis of HRV, are more susceptible to developing PTSD as a short and long-term outcome.