Introduction: It is well established that hemodynamic dysfunction, resulting in diminished upper-extremity work capacity, occurs in persons with spinal cord injury (SCI) as compared with those who are nondisabled (ND). Although it has been shown that persons with paraplegia display higher values of heart rate (HR) with lower values of stroke volume (SV) during exercise, it is not resolved whether there is adequate compensation to produce similar values of cardiac output (Q̇) as in ND. Purpose: This study examined central cardiovascular responses (HR, SV, and Q̇) of 20 subjects with complete thoracic level SCI (T4-T11) and 20 sedentary ND subjects during matched levels of arm-crank (AC) exercise. Methods: All subjects performed an incremental peak AC test to volitional exhaustion with continuous metabolic analysis and HR measurement via open circuit spirometry and 12-lead electrocardiography, respectively. Stroke volume was assessed using transthoracic impedance. Results: Heart rate was higher for SCI (P < 0.05) with significantly lower values for SV and Q̇ at rest (∼25%). Peak responses were significantly higher for ND in all factors except HR. Although subpeak HRs at matched absolute workloads were significantly higher for SCI (12-20 beats·min-1), SV and Q̇ were significantly lower (P < 0.05). Conclusions: The results of this study indicate that Q̇ is significantly lower in SCI than in ND during AC, despite significantly greater values of HR. These findings also suggest that the disparity in exercise values of Q̇ is related to differences exhibited at rest.
- Arm ergometry
- Cardiac output
- Spinal cord injury
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health
- Physical Therapy, Sports Therapy and Rehabilitation
- Orthopedics and Sports Medicine