Posttraumatic stress disorder was associated with significantly higher baseline heart rate, higher LF/HF ratio, and blunted diurnal differences compared to combat controls.
Observational (n=15)
Does posttraumatic stress disorder alter heart rate dynamics and diurnal variation in deployed male subjects with combat exposure?
PTSD is associated with diminished tonic parasympathetic activity and blunted diurnal heart rate variation, suggesting central neuroautonomic dysregulation that may link PTSD to increased cardiovascular risk.
Affected autonomic heart regulation is implicated in the pathophysiology of cardiovascular diseases and is associated with posttraumatic stress disorder (PTSD). However, although sympathetic hyperactivation has been repeatedly shown in PTSD, research has neglected parasympathetic function. The objective of this study is the long-term assessment of heart rate (HR) dynamics and its diurnal changes as an index of autonomic imbalance in PTSD. Since tonic parasympathetic activity underlies long-range correlation of heartbeat interval fluctuations in the healthy state, we included nonlinear (unifractal) analysis as an important and sensitive readout to assess functional alterations. We conducted electrocardiogram recordings over a 24-h period in 15 deployed male subjects with moderate to high levels of combat exposure (PTSD: n = 7; combat controls: n = 8) in the supine position. HR dynamics were assessed in two 5-h sub-epochs in the time and frequency domains, and by nonlinear analysis based on detrended fluctuation analysis. Psychiatric symptoms were assessed using structured interviews, including the Clinician Administered PTSD Scale. Subjects with PTSD showed significantly higher baseline HR, higher LF/HF ratio in the frequency domain, blunted differences between day and night-time measures, as well as a higher scaling coefficient αfast during the day, indicating diminished tonic parasympathetic activity. Diminished diurnal differences and blunted tonic parasympathetic activity altering HR dynamics suggest central neuroautonomic dysregulation that could represent a possible link to increased cardiovascular disease in PTSD.
Agorastos et al. (Tue,) conducted a observational in Posttraumatic stress disorder (PTSD) (n=15). Posttraumatic stress disorder (Exposure) vs. Combat controls was evaluated on Heart rate (HR) dynamics and diurnal changes (assessed in time/frequency domains and nonlinear analysis). Posttraumatic stress disorder was associated with significantly higher baseline heart rate, higher LF/HF ratio, and blunted diurnal differences compared to combat controls.