Analysis of heart rate variability in posttraumatic stress disorder patients in response to a trauma-related reminder

Spectral analysis of heart rate variability has recently been shown to be a reliable noninvasive test for quantitative assessment of cardiovascular autonomic regulatory responses, providing a dynamic map of sympathetic and parasympathetic interaction. In a prior study exploring the state of hyperarousal characterizing the posttraumatic stress disorder (PTSD) syndrome, the authors described standardized heart rate analysis carried out in 9 PTSD patients at rest, which demonstrated clear-cut evidence of a baseline autonomic hyperarousal state.

To examine the dynamics of this hyperarousal state, standardized heart rate analysis was carried out in 9 PTSD patients compared to a matched control group of 9 healthy volunteers. Twenty-minute recordings of electrocardiogram in response to a trauma-related cue as opposed to a resting state were performed and analyzed. The PTSD patients were asked to recount the presumed triggering traumatic event, and the control subjects recounted a significant stressful negative life event.

Our results show that, whereas the control subjects demonstrated significant autonomic responses to the stressogenic stimulus supplied by the recounting of a major stressful experience, the PTSD patients demonstrated almost no autonomic response to the recounting of the triggering stressful event. The PTSD patients demonstrated a degree of autonomic dysregulation at rest which was comparable to that seen in the control subjects' reaction to the stress model.

The lack of response to the stress model applied in the study appears to imply that PTSD patients experience so great a degree of autonomic hyperactivation at rest, that they are unable to marshal a further stress response to the recounting of the triggering trauma, as compared to control subjects.