A prospective study of heart rate response following trauma and the subsequent development of posttraumatic stress disorder

Background: Physiological arousal during traumatic events may trigger the neurobiological processes that lead to posttraumatic stress disorder (PTSD). This study prospectively examined the relationship between heart rate and blood pressure recorded immediately following a traumatic event and the subsequent development of PTSD. Methods: Eighty-six trauma survivors who presentd at the emergency department of a general hospital were followed up for 4 months. Heart rate and blood pressure were recorded on arrival at the emergency department. Heart rate, anxiety, depression, and PTSD symptoms were assessed 1 week, 1 month, and 4 months later. The clinician-administered PTSD scale defined PTSD status at 4 months. Results: Twenty subjects (23%) met PTSD diagnostic criteria at the 4-month assessment (PTSD group), and 66 (77%) did not (non-PTSD group). Subjects who developed PTSD had higher heart rates at the emergency department (95.5+/-13.9 vs 83.3+/-10.9 beats per minute, t=4.4, P<.001) and 1 week later (77.8+/-11.9 vs 72.0+/-4.5 beats per minute, t=2.25, P<.03), but not after 1 and 4 months. The groups did not differ in initial blood pressure measurement. Repeated-measures analysis of variance (ANOVA) for heart rate showed a significant group effect (P<.02), time effect (P<.001), and group x time interaction (P<.001). The time effect and group x time interaction remained significant when adjusted for sex, age, trauma severity, immediate response, and dissociation during the traumatic event. Conclusion: Elevated heart rate shortly after trauma is associated with the later development of PTSD.