Abstract
OBJECTIVE: Decentralized autonomic cardiovascular regulation may lead to increased prevalence of heart rate (HR) and blood pressure (BP) abnormalities in veterans with SCI. In addition, comorbid medical conditions and prescription medication use may increase HR and BP abnormalities. These abnormalities include bradycardia, and tachycardia, hypotension, hypertension as well as autonomic dysreflexia and orthostatic hypotension; the prevalence of which is unknown. DESIGN: HR and BP data were measured during a routine annual physical examination in 64 veterans with SCI. Measurements of HR and BP were recorded in the seated and supine positions to document the influence of body position and to document intra-subject variability in these assessments. RESULTS: All subjects were chronically injured (20 ± 14 years), 33 subjects were tetraplegic (T: C3-C8), nine had high paraplegia (HP: T1-T6), and 22 had low paraplegia (LP: T7-L2). Regardless of position, the prevalence of bradycardia was increased in the T group, whereas prevalence of tachycardia was increased in the HP and LP groups. Systolic hypotension was more common in the T and HP groups than the LP group and positional effects were most evident in the T group. Systolic hypertension was comparable in the T and HP groups but was twice as prevalent in the LP group. Increased prevalence of individuals with three or more medical conditions and prescribed three or more medications which might influence HR and BP was observed. CONCLUSION: Decentralized autonomic regulation, comorbid medical conditions, and prescription medication use in veterans with SCI result in HR and BP abnormalities; our data suggest that these abnormalities vary depending on the level of injury and orthostatic positioning.