Muscle metaboreflex is blunted with reduced vascular resistance response of nonexercised limb in patients with chronic heart failure

Kon, Hisashi; Nakamura, Motoyuki; Arakawa, Naoshi; Hiramori, Katsuhiko

doi:10.1016/j.cardfail.2004.02.007

Cited by 14 publications

(14 citation statements)

References 36 publications

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“…Others have argued that the muscle metaboreflex is diminished in HFrEF (Kon et al . ) and the muscle mechanoreflex, augmented (Middlekauff et al . ), perhaps due to between‐laboratory differences with respect to the autonomic integrity of HFrEF and control populations studied, the posture at which handgrip was performed and the exercise protocols themselves (Notarius & Floras, ).…”

Section: Discussionmentioning

confidence: 99%

Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age‐matched healthy subjects

Notarius

Millar

Murai

et al. 2014

The Journal of Physiology

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Key pointsr People with diminished ventricular contraction who develop heart failure have higher sympathetic nerve firing rates at rest compared with healthy individuals of a similar age and this is associated with less exercise capacity.r During handgrip exercise, sympathetic nerve activity to muscle is higher in patients with heart failure but the response to leg exercise is unknown because its recording requires stillness.r We measured sympathetic activity from one leg while the other leg cycled at a moderate level and observed a decrease in nerve firing rate in healthy subjects but an increase in subjects with heart failure.r Because these nerves release noradrenaline, which can restrict muscle blood flow, this observation helps explain the limited exercise capacity of patients with heart failure.r Lower nerve traffic during exercise was associated with greater peak oxygen uptake, suggesting that if exercise training attenuated sympathetic outflow functional capacity in heart failure would improve. AbstractThe reflex fibular muscle sympathetic nerve (MSNA) response to dynamic handgrip exercise is elicited at a lower threshold in heart failure with reduced ejection fraction (HFrEF). The present aim was to test the hypothesis that the contralateral MSNA response to mild to moderate dynamic one-legged exercise is augmented in HFrEF relative to age-and sex-matched controls. Heart rate (HR), blood pressure and MSNA were recorded in 16 patients with HFrEF (left ventricular ejection fraction = 31 ± 2%; age 62 ± 3 years, mean ± SE) and 13 healthy control subjects (56 ± 2 years) before and during 2 min of upright one-legged unloaded cycling followed by 2 min at 50% of peak oxygen uptake (V O 2 ,peak ). Resting HR and blood pressure were similar between groups whereas MSNA burst frequency was higher (50.0 ± 2.0 vs. 42.3 ± 2.7 bursts min −1 , P = 0.03) andV O 2 ,peak lower (18.0 ± 2.0 vs. 32.6 ± 2.8 ml kg −1 min −1 , P < 0.001) in HFrEF. Exercise increased HR (P < 0.001) with no group difference (P = 0.1). MSNA burst frequency decreased during mild to moderate dynamic exercise in the healthy controls but increased in HFrEF (−5.5 ± 2.0 vs. 6.9 ± 1.8 bursts min −1 , P < 0.001). Exercise capacity correlated inversely with MSNA burst frequency at 50%V O 2 ,peak (n = 29; r = −0.64; P < 0.001). At the same relative workload, one-legged dynamic exercise elicited a fall in MSNA burst frequency in healthy subjects but sympathoexcitation in HFrEF, a divergence probably reflecting between-group differences in reflexes engaged by cycling. This finding, coupled with an inverse relationship between MSNA burst frequency during loaded cycling and subjects'V O 2 ,peak , is consistent with a neurogenic determinant of exercise capacity in HFrEF. Abbreviations HFrEF, heart failure due to reduced ejection fraction; HR, heart rate; MSNA, muscle sympathetic nerve activity; RPE, rating of perceived exertion;V O2,peak , peak oxygen uptake.

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Section: Discussionmentioning

confidence: 99%

Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age‐matched healthy subjects

Notarius

Millar

Murai

et al. 2014

The Journal of Physiology

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“…18 Previous studies have varying results as to the degree of exercise-induced vasoconstrictive responses in the nonexercising vascular beds in patients with CHF. In the present study, FVR was higher in the resting state and at peak exercise in CHF patients, and the % increase in FVR was lower (Fig 1).…”

Section: Vasoconstrictive Responses In Normal Subjects and Chf Patientsmentioning

confidence: 99%

Vasoconstrictive Response in the Vascular Beds of the Non-Exercising Forearm During Leg Exercise in Patients With Mild Chronic Heart Failure

Chiba

Maehara

Yaoita

et al. 2007

Circ J

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Background Reduced exercise capacity may be related to decreased redistribution of blood flow from the nonexercising tissues to the exercising skeletal muscle in patients with mild chronic heart failure (CHF). Methods and ResultsIn the present study 14 patients with mild CHF and 10 healthy subjects (N) underwent symptom-limited multistage-ergometer exercise, during which forearm vascular resistance (FVR), cardiac index (CI), systemic vascular resistance index (SVRI), and oxygen uptake (V • O2) were measured non-invasively using the plethysmograph, impedance, and respiratory gas analysis methods, respectively. The V • O2 and CI at peak exercise were lower (p<0.01 each), and SVRI and FVR at both rest and peak exercise were higher in the CHF group than in N. However, both the percent increase in FVR and percent decrease in SVRI from the resting state to peak exercise were lower in CHF than N, and both of them correlated with not only peak V• O2, but also the corresponding resting value of FVR and SVRI (p<0.01 each). Conclusions Redistribution of blood flow from the non-exercising tissues to the working skeletal muscles, which may participate in exercise capacity, can be blunted in CHF. The decreased vasoconstrictive response in the non-exercising tissues is intimately related to the increased resting vascular tone in CHF. (Circ J 2007; 71: 922 -928)

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“…However, the hemodynamic and metabolic effects of left ventricular (LV) and BiV pacing during all-day moderate physical activity may be different from results obtained under resting conditions, e.g. due to altered systolic/diastolic intervals [7, 8], changes in peripheral vascular resistance [9], functional mitral regurgitation [10], alterations in the ergoreflex [11] or other peripheral adaptations [12]. …”

Section: Introductionmentioning

confidence: 99%

Impact of All-Day Physical Activity on Ventilatory Perfusion Coupling in Patients Undergoing Cardiac Resynchronization Therapy

Berger¹,

Zwick

Poelzl³

et al. 2008

Cardiology

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Objectives: There is still little information about the cardiorespiratory effects of cardiac resynchronization therapy (CRT) in patients undergoing all-day physical activity. This study aimed to assess the effects of CRT on ventilatory perfusion coupling during submaximal exercise. Methods: Metabolic and hemodynamic parameters were obtained during treadmill exercise testing as well as during rest for each single-right (RV), -left (LV) and biventricular (BiV) pacing mode as well as during intrinsic conduction (VVI 30) in 37 patients. Only responders to CRT (>10% increase in cardiac output (CO) during BiV pacing; n = 27) were included into the evaluation. Results: LV and BiV pacing increased systolic (144 ± 25 and 142 ± 28 vs. 118 ± 29 mm Hg, p < 0.05) and mean blood pressure (108 ± 19 and 109 ± 19 vs. 94 ± 25 mm Hg, p < 0.05) as well as CO (7.0 ± 0.6 and 7.2 ± 0.8 vs. 6.0 ± 0.6 l/min, p < 0.05 and p < 0.01) during exercise as compared to VVI 30. Simultaneously, LV and BiV pacing decreased dead space ventilation (18 ± 3 and 17 ± 3 vs. 20 ± 4, p < 0.01) and the ventilatory equivalent for oxygen (31 ± 4 and 31 ± 5 vs. 36 ± 6; p < 0.05) compared to intrinsic conduction. Conclusion: The improvement in ventilatory efficacy during CRT, which is demonstrated by the decrease in the ventilatory equivalent for oxygen, results from an increase in CO and thus from a reduction in the ventilatory perfusion mismatch.

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Muscle metaboreflex is blunted with reduced vascular resistance response of nonexercised limb in patients with chronic heart failure

Cited by 14 publications

References 36 publications

Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age‐matched healthy subjects

Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age‐matched healthy subjects

Vasoconstrictive Response in the Vascular Beds of the Non-Exercising Forearm During Leg Exercise in Patients With Mild Chronic Heart Failure

Impact of All-Day Physical Activity on Ventilatory Perfusion Coupling in Patients Undergoing Cardiac Resynchronization Therapy

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