Prevalence of Abnormal Systemic Hemodynamics in Veterans with and without Spinal Cord Injury

Higher frequency of heart rate (HR) and blood pressure (BP) abnormalities are evident in persons with spinal cord injury (SCI); but age, comorbid medical conditions and prescription medication use may contribute. This study aimed to determine differences in the prevalence of cardiac acceleration (CA: HR ≥ 80 bpm), hypotension (HYPO: BP ≤110/70 mmHg), orthostatic hypotension (OH: -20/-10 mmHg with upright positioning), and hypertension (HTN: BP ≥ 140/90 mmHg) in veterans with and without SCI. Subjects included 62 veterans with SCI: cervical (Tetra: C3-C8), high thoracic (T1-T5) and low thoracic (T7-L2) and 160 veterans without SCI (non-SCI). Medical history, prescription medication use, and HR and BP were assessed during a routine clinical visit. Prevalence rates of CA, HYPO, OH, and HTN were calculated using binary logistic regression analysis with 95% confidence intervals, and the affect of SCI status, age, smoking status, cardiovascular diagnoses, and use of prescribed anti-HTN medications on the prevalence of abnormal HR and BP recordings was determined. The diagnosis of HTN was reduced in the high thoracic and tetra groups compared to the non-SCI and low thoracic groups. Use of anti-HTN medications was increased in the low thoracic compared to the other 3 groups and was increased in the non-SCI compared to the tetra group. The prevalence of CA was decreased and the prevalence of systolic HYPO was increased in the tetra group. The prevalence of diastolic HYPO was increased in all SCI groups compared to the non-SCI group. For all analyses, increased prevalence of abnormal HR and BP recordings was not further explained by the covariates, with the exception of age, cardiovascular diagnoses and anti-HTN medications in the CA model; however, SCI status remained significant and was the dominant predictor variable.

These data indicate that SCI status contributes to the prevalence of CA, systolic and diastolic HYPO regardless of cardiovascular medical conditions or prescription anti-HTN medication use.