Investigating the heart rate variability patterns of posttraumatic stress patients using principal components analysis

Posttraumatic stress disorder (PTSD) afflicts individuals who have recently experienced terrifying traumatic events. Due to the debilitating effects of the disorder, it is important to uncover the physiology behind its early determinants. We have proposed a principal components analysis (PCA) for the study of heart rate variability (HRV) during sleep of patients with PTSD. Specifically, we studied one group whose PTSD symptoms lasted less than two months (PTSD-) and another group whose symptoms lasted for a longer period of time (PTSD+). After decomposing the subjects´ HRV signals into their components and finding the energy associated with each of the principal components, we found higher complexity in the signals for the PTSD- group than for the PTSD+ group.