Cardiovascular reactivity and the role of anxiety sensitivity in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) has long been characterized by its heightened stress response across a variety of cardiovascular measures. The current literature suggests this exaggerated response may be driven by either sympathetic overactivation, heightened parasympathetic withdrawal, or both. However, there has yet to be a study utilizing strong methodology incorporating cardiovascular reactivity measures of both the sympathetic nervous system (i.e., pre-ejection period) and parasympathetic nervous system (i.e., respiratory sinus arrhythmia). Additionally, anxiety sensitivity, or the fear of anxiety-related bodily sensations, is thought to influence the stress response by further heightening physiological reactivity. Research has yet to examine whether anxiety sensitivity accounts for changes in cardiovascular reactivity while controlling for PTSD. The current study sought to understand how the autonomic nervous system and its two branches (i.e., parasympathetic and sympathetic) influence cardiovascular reactivity during the stress response in PTSD and whether anxiety sensitivity influences that reactivity. The current study used a modified trauma-script imagery task to examine changes in cardiovascular measures across participants with PTSD (n = 53) and trauma exposed controls (n = 68). Results indicated heightened heart rate reactivity in PTSD compared to controls. The current study found marginal evidence of heightened reactivity in PTSD for pre-ejection period and no evidence of heightened respiratory sinus arrhythmia reactivity, suggesting that heart rate reactivity is driven more by sympathetic activity. There was no evidence to suggest that anxiety sensitivity influences cardiovascular changes. Further research is needed to better understand sympathetic influences on heart rate reactivity in PTSD. Future implications for treatment targeting the cardiovascular stress response to improve PTSD symptoms and the association between PTSD and poor cardiovascular health are considered