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 (.Q) as in ND. PURPOSE: This study examined central cardiovascular responses (HR, SV, and .Q) of 20 subjects with complete thoracic level SCI (T(4)-T(11)) 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 .Q at rest (approximately 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 .Q were significantly lower (P< 0.05). CONCLUSIONS: The results of this study indicate that .Q 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 .Q is related to differences exhibited at rest.
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 (.Q) as in ND. PURPOSE: This study examined central cardiovascular responses (HR, SV, and .Q) of 20 subjects with complete thoracic level SCI (T(4)-T(11)) 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 .Q at rest (approximately 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 .Q were significantly lower (P< 0.05). CONCLUSIONS: The results of this study indicate that .Q 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 .Q is related to differences exhibited at rest.
Authors: Heidi L Lujan; Gurunanthan Palani; Jean D Peduzzi; Stephen E DiCarlo Journal: Am J Physiol Regul Integr Comp Physiol Date: 2010-03-10 Impact factor: 3.619
Authors: Dwindally Rosado-Rivera; M Radulovic; John P Handrakis; Christopher M Cirnigliaro; A Marley Jensen; Steve Kirshblum; William A Bauman; Jill Maria Wecht Journal: J Spinal Cord Med Date: 2011 Impact factor: 1.985
Authors: William A Bauman; Mark A Korsten; Miroslav Radulovic; Gregory J Schilero; Jill M Wecht; Ann M Spungen Journal: Top Spinal Cord Inj Rehabil Date: 2012