The Effect of Acute Dynamic Handgrip Exercise on Arterial Stiffness in Patients With Fontan Circulation

Central arterial stiffness is common in patients with Fontan circulation (FTN). Whether arterial stiffness exists in conduit arteries supplying skeletal muscle and persists during exercise in FTN remains unknown. We tested the hypothesis that 1) resting Peterson’s elastic modulus would be greater and compliance would be lower in patients with FTN; and 2) exercise-induced reductions in Peterson’s elastic modulus and increases in compliance would be attenuated in patients with FTN. Brachial artery diameter (high-resolution ultrasound) and blood pressure (finger photoplethysmography) were analyzed across 5 consecutive cardiac cycles at rest and during steady-state dynamic handgrip exercise (20% MVC) in patients with FTN ( n =8 (4 F), 17±3 yrs; BMI = 25±6 kg/m 2 ) and healthy control participants (CTL; n =5 (3 F), 20±3 yrs; BMI = 24±4 kg/m 2 ). Rest and exercise data using absolute values were analyzed by 2 x 2 ANOVA. Peterson’s elastic modulus was augmented in FTN (FTN=4752±2744 vs. CTL=4661±1364 mmHg, P =0.0613), and tended to decrease with exercise across both groups ( P =0.0701). Furthermore, an interaction effect ( P =0.0189) revealed that despite no between group differences ( P =0.1393), arterial compliance increased from rest to exercise in CTL ( P =0.0052), but not in FTN ( P =0.9743). Collectively, patients with FTN tended to have greater arterial stiffness and attenuated increases in compliance during dynamic exercise. Increased arterial stiffness in FTN is unlikely to be changed with one bout of exercise. Saskatchewan Centre for Patient Oriented Research, Heart and Stroke Foundation of Canada This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.