Publications by authors named "Kathryn A Harman"

Injury to descending autonomic (sympathetic) pathways is common after high-level spinal cord injury (SCI) and associated with abnormal blood pressure and heart rate regulation. In individuals with high-level SCI, abnormal sympathovagal balance (such as during autonomic dysreflexia; paroxysmal hypertension provoked by sensory stimuli below the injury) is proarrhythmogenic. Exercise training is a key component of SCI rehabilitation and management of cardiovascular disease risk, but it is unclear whether exercise training influences susceptibility to cardiac arrhythmia.

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Article Synopsis
  • Hemodynamic instability and cardiovascular dysfunction are common in individuals with cervical and high thoracic spinal cord injuries, leading to symptoms like autonomic dysreflexia and persistent low blood pressure that affect daily activities.
  • This study evaluated the effects of two exercise modalities—passive hindlimb cycling and active forelimb swimming—on hemodynamic stability and autonomic function in an animal model of incomplete spinal cord injury.
  • Results indicated that short-term exercise training did not improve resting blood pressure or reduce autonomic dysreflexia severity, and that locomotor recovery affected the severity of autonomic dysreflexia in these subjects.
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Reduced muscle mass and increased fatiguability are major complications after spinal cord injury (SCI), and often hinder the rehabilitation efforts of patients. Such detriments to the musculoskeletal system, and the concomitant reduction in level of activity, contribute to secondary complications such as cardiovascular disease, diabetes, bladder dysfunction and liver damage. As a result of decreased weight-bearing capacity after SCI, muscles undergo morphological, metabolic, and contractile changes.

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Multi-organ dysfunction is a major complication after spinal cord injury (SCI). In addition to local injury within the spinal cord, SCI causes major disruption to the peripheral organ innervation and regulation. The liver contains sympathetic, parasympathetic, and small sensory axons.

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Spinal cord injury (SCI) is a devastating condition that results in whole-body dysfunction, notably cardiovascular (CV) disruption and disease. Injury-induced destruction of autonomic pathways in conjunction with a progressive decline in physical fitness contribute to the poor CV status of SCI individuals. Despite the wide use of exercise training as a therapeutic option to reduce CV dysfunction, little is known about the acute hemodynamic responses to the exercise itself.

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Active upper-limb and passive lower-limb exercise are two interventions used in the spinal cord injury (SCI) population. Although the global cardiac responses have been previously studied, it is unclear how either exercise influences contractile cardiac function. Here, the cardiac contractile and volumetric responses to upper-limb (swim) and passive lower-limb exercise were investigated in rodents with a severe high-thoracic SCI.

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Individuals with spinal cord injury (SCI) have been shown to exhibit systolic, and to a lesser extent, diastolic cardiac dysfunction. However, previous reports of cardiac dysfunction in this population are confounded by the changing loading conditions after SCI and as such, whether cardiac dysfunction per se is present is still unknown. Therefore, our aim was to establish if load-independent cardiac dysfunction is present after SCI, to understand the functional cardiac response to SCI, and to explore the changes within the cellular milieu of the myocardium.

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