Cardiac responses to spinal cord injury and exercise

The prognosis for the 2.5 million North Americans living with spinal cord injury (SCI) is poor. These wheelchair bound individuals are subjected to a number of physical, social, and environmental barriers that compound paralysis and limit daily physical activity. The five-fold increase in risk for heart disease reduces life-expectancy and costs the North American healthcare system $3 billion per annum.

Heart disease is the number one cause of illness and death in the SCI population. On a daily basis, these individuals are tasked with managing abnormal blood pressure control, fatigue, and a host of other bowel and bladder problems. Chronic management of these ‘secondary’ conditions can be poor, owing primarily to a lack of understanding of the underlying mechanisms. In able-bodied individuals, regular physical activity has multiple cardiovascular benefits. Although numerous attempts have been made to engage SCI individuals in regular physical activity, there is limited information available on the cardiovascular benefits of exercise in SCI individuals.

The primary aim of this research project is to investigate the effects of daily physical activity and structured exercise on heart function after SCI.

To improve our understanding of how the heart changes after SCI and the effectiveness of exercise, Dr. West will conduct simultaneous studies in rodents and humans with SCI. The use of a clinically relevant rodent model of SCI will allow Dr. West to answer fundamental questions about cardiac structure and function, and what mechanisms are responsible for the changes that occur after SCI and exercise. The findings will then be translated through conducting assessments of the heart in individuals with SCI.

This project is unique as it will be the first to use ultrasound to make identical measures of heart function in both rodents and humans. Additionally, Dr. West will be able to conduct direct assessments of heart function in the rodent model and follow this up with a detailed examination of the structure of the heart. Finally, he will conduct novel experiments into the effect of lower-limb passive cycling in rodents with SCI and follow this up by assessing how the heart responds to a novel passive leg energetic arm exercise intervention in humans.

Results from this study will yield vital information that can be used to assist in the rehabilitation and management of individuals with SCI.