Vascular and Ventricular Responses Assessed by Exercise Stress Echocardiography in Pediatric Marfan Syndrome.

Background: Pediatric Marfan syndrome (MFS) is associated with changes in aortic stiffness, endothelial function, and ventricular performance. Resting measurements may not fully capture cardiovascular functional reserve. Exercise stress echocardiography can reveal subclinical impairments not evident at rest. Methods: This study included 31 pediatric patients with and 31 age-matched controls. Resting and exercise echocardiography were performed to assess systolic and diastolic function, aortic dimensions, and vascular parameters. Results: Patients with MFS had larger baseline height and body surface area values compared with controls. Significant baseline differences in aortic dimensions, diastolic function, endothelial function, and vascular stiffness were observed in patients with MFS. Despite these differences, patients with MFS demonstrated preserved systolic and diastolic reserve during exercise. Vascular responses to exercise were comparable to controls, reflecting increased stiffness and altered endothelial function but preserved adaptability. Conclusions: Preserved cardiovascular reserve during exercise suggests that baseline abnormalities may not result in significant dysfunction, supporting safe participation in endurance activities for pediatric patients with MFS.