Investigating Heart Rate Patterns During Hyperarousal Events Among Veterans Who Have Posttraumatic Stress Disorder (PTSD)
TimeFriday, April 161:10pm - 1:30pm EDT
DescriptionInvestigating Heart Rate Patterns During Hyperarousal Events Among Veterans Who Have Posttraumatic Stress Disorder (PTSD)
Posttraumatic Stress Disorder (PTSD) is a prevalent psychiatric condition affecting over 24% of combat veterans in the United States (Spottswood et al., 2017). The main symptoms of PTSD are hyperarousal, reexperiencing trauma, flash backs, and intrusive thoughts (American Psychiatric Association, 2013). Prior studies have looked into the effects of PTSD on physiological markers including heart rate measures, blood pressure and skin conductance (Nagpal et al., 2013). Heart rate measures such as heart rate variability, and time domain and frequency domain features of heart rate are the main physiological indicators of PTSD (Sadeghi et al., 2019, 2020). However, there is limited knowledge of heart rate profiles and patterns during PTSD hyperarousal events. The goal of this presentation is to share findings from a large naturalistic study to understand and model heart rate patterns during PTSD hyperarousal events. Cardiac data was collected from 99 veterans who were diagnosed with PTSD during various Project Hero riding challenges. Project Hero is a non-profit organization committed to helping veterans and first responders diagnosed with PTSD by coordinating recreational events such as group biking as part of a social therapy effort. During each event participant rode bikes for an average of 3-7 days. Participants were provided with smartwatches with a custom-built application (app) that could remotely and continuously monitor and collect heart rate and body motion data. The app also allowed for subjectively self-reporting hyperarousal events by tapping on the watch’s interface. Cardiac data was inspected using Autoregressive Integrated Moving Average (ARIMA) to detect heart rate patterns associated with PTSD hyperarousal events. To do so, we used 600 seconds window of heart rate data (100 seconds before and 500 seconds after reported hyperarousal events). We then compared these windows with heart rate data from 11 healthy subjects in resting position. We found out that heart rate shows specific patterns during hyperarousal events in terms of stationarity, autocorrelation, and fluctuation. The analysis showed that heart rate is more non stationary during hyperarousal events compared to heart rate in healthy subjects meaning that heart rate has more chaotic patterns during hyperarousal events. Moreover, the autocorrelation function’s sign (which represents intercorrelation between observations) changes less often during hyperarousal events. Finally, heart rate fluctuates more during hyperarousal events compared to sample data from healthy subjects. While the study shows promises in detecting heart rate patterns during hyperarousal evets, several limitations are associated with the study. Firstly, hyperarousal events were reported subjectively and might have affected by individual biases. Additionally, the data was collected in naturalistic settings using smart watches. This allowed the collection of “ground truth” in natural settings in which they happened that has high levels of external validity, but the lack of control over participants’ activity or other contextual variables introduced significant “noise” in the data. Future work is needed to address these limitations.
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Nagpal, M., Gleichauf, K., & Ginsberg, J. (2013). Meta-analysis of heart rate variability as a psychophysiological indicator of posttraumatic stress disorder. Journal of Trauma & Treatment, 3, 1000182. doi:10.4172/2167-1222.1000182
Sadeghi, M., Sasangohar, F., & McDonald, A.D. (2019, November). Analyzing heart rate as a physiological indicator of post-traumatic stress disorder: A scoping literature review. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 63, 1936-1936.
Sadeghi, M., Sasangohar, F., & McDonald, A.D. (2020). Towards a taxonomy for analyzing heart rate as a physiological indicator of post-traumatic stress disorder (PTSD). JMIR Mental Health. In press. doi:10.2196/16654