Assessment of exercise stroke volume and its prediction from oxygen pulse in Paralympic Athletes with locomotor impairments: cardiac long-term adaptations are possible.

The determinants of cardiac output (CO) during exercise, i.e., stroke volume (SV) and heart rate (HR), could differ in Paralympic athletes (PAthl) with spinal cord injury (SCI) with respect to PAthl with locomotor impairments caused by different health conditions (HC). The purposes of the present study were the comparisons of two groups of PAthl, one with SCI and one with either amputation (AMP) or post poliomyelitis syndrome (PM), assessing the: (1) peak cardiorespiratory responses and determinants (SV and HR) of CO during maximal and submaximal arm cranking exercise (ACE), respectively; (2) correlations between peak oxygen uptake (VO2peak) and the highest SV obtained during submaximal exercise; and (3) correlations between oxygen pulse (O2 pulse, ratio between VO2 and HR) and both SV and O2 arterio-venous difference [(a-v)O2diff]. Each athlete (19 PAthl with SCI, 9 with AMP and 5 with PM) completed a continuous incremental cardiopulmonary ACE test to volitional fatigue to assess peak responses. In a different session CO was indirectly estimated by carbon dioxide (CO2) rebreathing at sub-maximal exercise intensities approximating 30%, 50% and 70% of the VO2peak. There were no significant differences between the PAthl groups in age, anthropometry and VO2peak. However, peak HR was significantly lower and peak O2 pulse was significantly higher in PAthl with AMP/PM compared to those with SCI. During sub-maximal exercise, PAthl with AMP/PM displayed significantly higher SV values...
Source: Frontiers in Physiology - Category: Physiology Source Type: research