Background: Impairment of the adaptive mechanisms that increase cardiac output during exercise can translate to a reduced functional capacity. We investigated cardiovascular adaptation to exertion in asymptomatic hypertensive patients, aiming to identify the early signs of cardiac and vascular dysfunction.
Methods and results: We enrolled 54 subjects: 30 patients (45.1±11.9years, 19 males) and 24 age-matched healthy controls (44.4±9.6years, 14 males). Speckle-tracking echocardiography (STE) and echo-tracking were performed at rest and during exertion to assess myocardial deformation and arterial stiffness.
Results: E/E' increased from rest to peak exercise more in patients than in controls (peak stage: p=0.024). Global longitudinal strain increased significantly from rest to peak stage in controls (p=0.011) whereas it remained unchanged in patients (p=0.777). Left atrial (LA) reservoir was significantly increased throughout the exercise only in controls (p=0.001) whereas it was almost unchanged in patients (p=0.293). LA stiffness was significantly higher in patients than in controls both at rest (p=0.023) and during exercise (p<0.001). Beta index and pulse wave velocity (PWV) increased during exercise in both groups, showing higher values in patients in each step.
Conclusions: Our study showed a more pronounced maladaptation during exercise, with respect to rest, of the cardiovascular system with impaired cardiac-vessel coupling in hypertensive patients compared to healthy subjects. Exercise echocardiography implemented by STE and echo-tracking is invaluable in the early detection of these cardiovascular abnormalities.
Keywords: Echo-tracking; Exercise echocardiography; Longitudinal function; Stiffness; Strain.
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