• PTSD;
  • Cardiac defense;
  • Heart rate;
  • Shutdown dissociation;
  • Sympathetic;
  • Parasympathetic


Posttraumatic stress disorder (PTSD) arises as a long-term result of exposure to trauma and brings with it an altered autonomic response to potentially threatening stimuli. The present study investigates the dynamic sequence of cardiac defense in women with and without PTSD. An acoustic noise of 0.5-s duration and 105 dB was used to elicit the cardiac defense reaction. The stimulus was repeated three times. Within the PTSD sample, respondents who suffered from more severe PTSD showed a higher heart rate at rest, a higher baseline, and a greater response. Compared to the healthy subjects, the PTSD group showed an elevated heart rate from 6 s to 25 s following the presentation of the first stimulus. There was evidence of habituation in the PTSD group and hints of differential effects on the cardiac defense of traumatic experiences with a high proximity of danger.