Cardiovascular activity and chronic pain severity

OBJECTIVE Objective markers of chronic pain severity are needed when examining and treating patients with chronic pain whose suffering may be overstated or underestimated. This study tested a hypothesis that the strength of cardiovascular (CV) reactivity in response to a social evaluative threat and orthostatic challenge is a reliable index of severity of pain-related complaints. METHODS Measurement of CV reactivity and response styles in 34 men and 16 women with chronic pain from different bodily injuries, were retrieved from a larger database of patients. Measurement of CV reactivity in response to a postural challenge was repeated twice (sessions 1 and 2) on the same day of a medical examination which includes a psychosocial evaluation . RESULTS A decrease in systolic blood pressure (SBP) from session 1 to session 2 was found in subjects with low pain severity scores, but not in those with high pain severity scores. High scores for pain catastrophizing/ magnification and pain-related emotional distress were independently associated respectively with a SBP increase at an early-point in time and a SBP decrease at a mid-point in time after standing up from lying down. Stronger heart rate reactivity responses to orthostatic challenge indicated greater protection against the presence of these chronic pain symptoms. CONCLUSIONS This biobehavioral protocol enables measurement of chronic pain suffering and protection in three dimensions: physical, emotional, and cognitive.