Ventricular vascular coupling in rodents and humans with spinal cord injury : a translational retrospective study

Spinal cord injury (SCI) is associated with cardiac atrophy, impaired systolic and diastolic function, and vascular stiffening. In able-bodied (AB) individuals, the heart and vasculature act in unison to ensure efficient coupling between the heart and the peripheral vasculature. The evaluation of the interaction between the vascular system and the heart is performed by measuring the vascular load imposed on the heart (arterial elastance), cardiac contractility (end-systolic elastance), and their ratio “ventricular-arterial coupling” (VAC). More specifically, arterial elastance (EA) is a parameter of the compliant properties of the arterial system and end-systolic elastance (Ees) determines the effectiveness of the heart as a pump. The VAC ratio is an important index of cardiac performance, linked to exercise capacity and predictor of both heart failure and cardiovascular (CV) mortality. Taken together these indices evaluate the mechanical efficiency of the cardiovascular system to meet the metabolic demands. A way to accurately evaluate this CV coupling is invasive and almost exclusively performed in animal models. However, a non-invasive approach to estimate VAC in the clinical scenario is through cardiac imaging and blood pressure measurement. In the field of SCI, research has only focused on evaluating these parameters in animal models, while in humans the heart and vasculature have been evaluated as independent units without investigating their “coupling.” The primary objective of this research was, therfore, to compare invasive and non-invasive parameters of cardiac systolic function in a validated SCI rodent model and translate these findings to humans. Additionally, to determine the parameter that better reflects the impaired systolic function in SCI, I will investigate two non-invasive approaches to assess systolic function and their vascular “coupling” in elite athletes with chronic cervical SCI, non-athlete chronic cervical SCI individuals and AB.Education, Faculty ofKinesiology, School ofGraduat