Arterial Stiffness and Central Hemodynamic Response and Recovery in Individuals Post-Stroke

Abstract

Background. Stroke affects over 80 million individuals worldwide. Elevated arterial stiffness has emerged as a novel independent risk marker for stroke. While arterial stiffness is improved after chronic aerobic training, a single bout of aerobic exercise leads to transient increases that typically resolve within 5 minutes of recovery. Elevated arterial stiffness may persist for up to 30 minutes following exercise in populations with cardiovascular disease. However, no study has examined the effect of acute aerobic exercise on arterial stiffness and central hemodynamics in individuals with stroke. Moreover, no study has explored the clinical significance of these responses. Objectives. The primary objective of this thesis was to characterize the response and recovery of arterial stiffness and central hemodynamics to peak aerobic exercise in individuals ≥ 6 months post-stroke. The secondary objective was to explore the relationships between the exercise response and recovery of arterial stiffness and central hemodynamics, with cardiorespiratory fitness and walking ability. Results. This cross-sectional study recruited 10 adults with stroke (mean ± SD age=56.9 ± 11.8; median [IQR]= 2.9 [1.9] years post-stroke; n=4 females). After peak aerobic exercise, cfPWV increased from rest and remained elevated for 20 minutes (p<0.05). Heart rate increased and remained elevated for 10 minutes post-exercise (p<0.05), while systolic blood pressure decreased and remained reduced for 15 minutes (p<0.05). Positive associations were found between cardiorespiratory fitness and heart rate reserve (r=0.74, p=0.02), and with each phase of heart rate recovery (HR60s r=0.80, p=0.005, HR120s r=0.79, p=0.006; HR300s r=0.72, p=0.02; and HR600s r=0.75, p=0.01). There were no relationships between response and recovery of hemodynamic variables with walking ability. Conclusion. Individuals with chronic stroke may have impaired arterial stiffness and heart rate recovery following peak aerobic exercise. Moreover, heart rate reserve and all phases of heart rate recovery were related to cardiorespiratory fitness, but not walking ability.