Cardiovascular responses to static handgrip exercise and postexercise ischemia in heart failure with preserved ejection fraction

Abstract

Exercise intolerance is a well-described characteristic of heart failure with preserved ejection fraction (HFpEF), but whether disease-related changes in autonomic function contribute to impaired cardiovascular control during exercise is not well understood. Thus, we used a combination of static handgrip exercise (HG) and post-exercise ischemia (PEI) to examine the pressor response to exercise and isolate the skeletal muscle metaboreflex, respectively. Mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) were assessed during 2-min of static HG at 30 and 40% of maximum voluntary contraction (MVC) and subsequent PEI in sixteen patients with HFpEF and seventeen healthy, similarly aged controls. Changes in MAP were lower in patients with HFpEF compared to controls during both 30%MVC (Δ11 ± 7 vs. Δ15 ± 8 mmHg) and 40%MVC (Δ19 ± 14 vs. Δ30 ± 8 mmHg), and a similar pattern of response was evident during PEI (30%MVC: Δ8 ± 5 vs. Δ12 ± 8 mmHg; 40%MVC: Δ13 ± 10 vs. Δ18 ± 9 mmHg) (group effect: p=0.048 and p=0.020 at 30% and 40% MVC, respectively). Changes in HR, CO, and TPR did not differ between groups during HG or PEI (p>0.05). Taken together, these data suggest a reduced pressor response to static muscle contractions in patients with HFpEF compared to similarly aged controls that may be mediated, in part, by a blunted muscle metaboreflex. These findings support a disease-related dysregulation in neural cardiovascular control that may contribute to the extreme exercise intolerance present in this patient group.