In patients with HFpEF, the paradoxical increase in muscle sympathetic nerve activity during moderate cycling related inversely to relative peak oxygen uptake (r=-0.72; P<0.01).
Observational (n=48)
Does the sympathetic response to exercise correlate with exercise capacity in patients with HFpEF?
Patients with HFpEF exhibit paradoxical sympathoexcitation during dynamic exercise, which inversely correlates with their exercise capacity, suggesting a neurogenic limit on exercise tolerance.
Effect estimate: r = -0.72
p-value: p=<0.01
BACKGROUND: In heart failure, sympathetic excess and exercise intolerance impair quality of life. In heart failure with reduced ejection fraction, exercise stimulates a reflex increase in muscle sympathetic nerve activity (MSNA) that relates inversely to peak oxygen uptake (V̇O 2peak ). Whether similar sympathoexcitatory responses are present in heart failure with preserved EF (HFpEF) and relate to V̇O 2peak are unknown. METHODS: In 13 patients with HFpEF (70±6 years), 17 comorbidity-matched controls (CMC; 67±8 years), and 18 healthy controls (65±8 years), we measured heart rate, blood pressure, and MSNA (microneurography) during (1) 7-minute baseline; (2) 2-minute isometric handgrip (40% maximal voluntary contraction) or rhythmic handgrip (50% and 30% maximal voluntary contraction) exercise, followed by 2-minute postexercise circulatory occlusion; and (3) 4-minute 1-leg cycling (2 minutes each at mild and moderate intensity). V̇O 2peak was obtained by open-circuit spirometry. RESULTS: Resting MSNA was higher and V̇O 2peak was lower in HFpEF versus CMCs and healthy controls (all P 0.05). CONCLUSIONS: In contrast to CMCs, patients with HFpEF exhibit augmented MSNA at rest and during exercise. The magnitude of such paradoxical sympathoexcitation during dynamic cycling relates inversely to V̇O 2peak , consistent with a neurogenic, vasoconstrictor limit on exercise capacity in HFpEF.
Badrov et al. (Fri,) conducted a observational in Heart failure with preserved ejection fraction (HFpEF) (n=48). 1-leg cycling and handgrip exercise vs. Comorbidity-matched controls and healthy controls was evaluated on Relationship between change in muscle sympathetic nerve activity (MSNA) during moderate cycling and relative VO2peak (r = -0.72, p=<0.01). In patients with HFpEF, the paradoxical increase in muscle sympathetic nerve activity during moderate cycling related inversely to relative peak oxygen uptake (r=-0.72; P<0.01).
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