Heart rate variability of chronic posttraumatic stress disorder in the Korean veterans.

Patients with post-traumatic stress disorder (PTSD) have lower heart rate variability (HRV) than the general population, but findings in this area have been inconsistent. This study was conducted to investigate the characteristics of HRV in patients with PTSD and to evaluate associations between PTSD symptoms and HRV indices. Sixty-eight patients with PTSD and 73 controls without PTSD were evaluated. HRV was measured in all subjects after they completed self-reported questionnaires. Patients with PTSD had significantly more depressed moods, anxiety, and poorer sleep quality than individuals in the non-PTSD group. Standard deviations of NN intervals (SDNN), the square root of the mean squared differences of successive NN intervals (RMSSD), and log high-frequency (LNHF) were significantly lower in the PTSD group than in the non-PTSD group. Comparisons of HRV indices among four sub-groups according to presence/absence of PTSD and experiences of combat-related or other trauma indicated that individuals in the PTSD group who had experienced combat-related trauma had the lowest HRV indices. These indices included SDNN, RMSSD, and LNHF. Further, SDNN, RMSSD, and HF power were significantly associated with symptoms of hyperarousal. HRV measures might be useful physiological parameters in assessing and monitoring sympathovagal function in patients with PTSD.