Autonomic activation during sleep in posttraumatic stress disorder and panic: a mattress actigraphic study.

BACKGROUND: While it has been reported that persons with posttraumatic stress disorder (PTSD) manifest tonic autonomic activation, the literature contains numerous counterexamples. In revisiting the question, this study employed a novel method of mattress actigraphy to unobtrusively estimate heart rate and respiratory sinus arrhythmia over multiple nights of sleep in the home.
METHODS: Sleep cardiac autonomic status was estimated in four diagnostic groups, posttraumatic stress disorder, panic disorder, persons comorbid for both conditions, and control subjects. All 59 participants were community-residing nonveterans screened for sleep apnea and periodic leg movement disorder with polysomnography. Heart rate and respiratory sinus arrhythmia were calculated from the kinetocardiogram signal measured via accelerometers embedded in a mattress topper. Times in bed and asleep were also estimated. Per participant data were obtained from a median of 12 nights.
RESULTS: Both posttraumatic stress disorder and posttraumatic stress disorder/panic disorder comorbid groups exhibited significantly higher heart rates and lower respiratory sinus arrhythmia magnitudes than panic disorder participants and control subjects. Panic disorder participants were indistinguishable from control subjects. The PTSD-only group exhibited longer times in bed and longer times presumably asleep than the other three groups.
CONCLUSIONS: In this study, posttraumatic stress disorder, but not panic disorder, was associated with altered cardiac autonomic status during sleep. Among participants meeting criteria for PTSD alone, autonomic activation co-occurred with prolongation of actigraphic sleep.