Exercise Training Does Not Attenuate Cardiac Atrophy or Loss of Function in Individuals With Acute Spinal Cord Injury: A Pilot Study

Objective: To investigate the effects of 2 modes of exercise training, upper-body alone, and the addition of electrical stimulation of the lower body, to attenuate cardiac atrophy and loss of function in individuals with acute spinal cord injury (SCI).Design: Randomized controlled trial.Setting: Rehabilitation Hospital.Participants: Volunteers (N=27; 5 women, 22 men) who were <24 months post SCI.Interventions: Volunteers completed either 6 months of no structured exercise (Control), arm rowing (AO), or a combination of arm rowing with electrical stimulation of lower body paralyzed muscle (functional electrical stimulation [FES] rowing).Main Outcome Measures: Transthoracic echocardiography was performed on each subject prior to and 6 months after the intervention. The rela-tions between time since injury and exercise type to cardiac structure and function were assessed via 2-way repeated-measures analysis of variance and with multilevel linear regression.Results: Time since injury was significantly associated with a continuous decline in cardiac structure and systolic function, specifically, a reduc-tion in left ventricular mass (0.197 g/month; P=.049), internal diameter during systole (0.255 mm/month; P<.001), and diastole (0.217 mm/month; P=.019), as well as cardiac output (0.048 L/month, P=.019), and left ventricular percent shortening (0.256 %/month; P=.027). These associations were not differentially affected by exercise (Control vs AO vs FES, P>.05).Conclusions: These results indicate that within the subacute phase of recovery from SCI there is a linear loss of left ventricular cardiac structure and systolic function that is not attenuated by current rehabilitative aerobic exercise practices. Reductions in cardiac structure and function may increase the risk of cardiovascular disease in individuals with SCI and warrants further interventions to prevent cardiac decline. Archives of Physical Medicine and Rehabilitation 2023;104:909-17 & COPY; 2022 by the American Congress of Rehabilitation Medicine.

Automated summary

This study aimed to investigate the effects of different exercise training modes on cardiac atrophy and loss of function in patients with acute spinal cord injury (SCI). The results showed that neither upper-body exercise alone nor a combination of upper-body exercise with lower-body electrical stimulation had a significant impact on cardiac structure and function. This suggests that current rehabilitative aerobic exercise practices are not effective in preventing cardiac decline in individuals with SCI and further interventions are needed.