Disruption of Bradycardia During Vigilance: Autonomic Cardiac Dysregulation is Prelude to Disinhibition, Hyperarousal, and Attention Bias in Combat Veterans with PTSD

Abstract

Abstract We propose a model to account for the post‐traumatic stress disorder (PTSD) symptoms of disinhibition, hyperarousal, and attention bias. We review the background literature which is the foundation on which our model rests, present key results of our ongoing research, and suggest testable hypotheses for further research. Our laboratory is in a Veterans Affairs (VA) Medical Center, where we began our work with a search for the significant causes and predictors of hyperarousal in combat veterans with PTSD using eyeblink and autonomic conditioning protocols. We believe our studies will lead to integration of a treatment intervention for war veterans (and equally as well for treatment of the traumatically stressed in the general population). Our research has begun to show strong associations between lowered heart rate variability (HRV) and PTSD. Loss of bradycardia during normal vigilance is the cause of lowered HRV, which impairs appraisal of threat value of environmental stimulation, thereby leading to disinhibition, hyperarousal, and attention bias toward and away from threat. The next steps of research we plan are outlined and designed to elucidate how HRV biofeedback is a promising intervention to increase HRV during vigilance of stimuli and restore cognitive appraisal and response selection, thereby reducing PTSD symptoms and normalizing behavior