Heart rate variability: Pre-deployment predictor of post-deployment PTSD symptoms

Area of Science:

• Autonomic Nervous System Physiology
• Psychotraumatology
• Military Mental Health

Background:

• Heart rate variability (HRV) reflects autonomic nervous system (ANS) activity.
• ANS dysfunction is implicated in the pathophysiology of post-traumatic stress disorder (PTSD).
• Understanding pre-deployment physiological markers may aid in predicting PTSD risk in military personnel.

Purpose of the Study:

• To investigate the association between pre-deployment heart rate variability (HRV) and post-deployment PTSD symptom severity.
• To determine if HRV metrics predict PTSD symptom development or exacerbation following combat deployment.

Main Methods:

• Analysis of 343 Army National Guard soldiers from the Warriors Achieving Resilience (WAR) study.
• Measurement of pre-deployment HRV using high frequency power (HF) and standard deviation of the normal cardiac inter-beat interval (SDNN).
• Assessment of PTSD symptom severity using the PTSD Checklist - Military version (PCL) at baseline, 3-, and 12-month post-deployment, analyzed with generalized linear mixed models.

Main Results:

• A significant interaction between pre-deployment PCL scores and ln(HF) predicted post-deployment PTSD symptoms (p<0.0001).
• Pre-deployment SDNN was not a significant predictor of post-deployment PTSD symptoms.
• The predictive relationship between HRV and PTSD was most pronounced in soldiers with higher baseline PCL scores.

Conclusions:

• Pre-deployment high frequency power (HF) of HRV is a significant predictor of post-deployment PTSD symptoms, especially when baseline PTSD symptom severity is high.
• HRV may serve as a valuable physiological biomarker for identifying soldiers at increased risk for developing PTSD.
• Further research into HRV-based interventions for PTSD prevention and treatment is warranted.