Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Jun 15;174(2):368-75.
doi: 10.1016/j.ijcard.2014.04.157. Epub 2014 Apr 21.

Group III/IV muscle afferents impair limb blood in patients with chronic heart failure

Markus Amann  1 , Massimo Venturelli  2 , Stephen J Ives  3 , David E Morgan  4 , Benjamin Gmelch  4 , Melissa A H Witman  3 , H Jonathan Groot  3 , D Walter Wray  5 , Josef Stehlik  2 , Russell S Richardson  5
Affiliations

Group III/IV muscle afferents impair limb blood in patients with chronic heart failure

Markus Amann et al. Int J Cardiol. .

Abstract

Objective: To better understand the hemodynamic and autonomic reflex abnormalities in heart-failure patients (HF), we investigated the influence of group III/IV muscle afferents on their cardiovascular response to rhythmic exercise.

Methods: Nine HF-patients (NYHA class-II, mean left ventricular ejection-fraction: 27 ± 3%) performed single leg knee-extensor exercise (25/50/80% peak-workload) under control conditions and with lumbar intrathecal fentanyl impairing μ-opioid receptor-sensitive muscle afferents.

Results: Cardiac-output (Q) and femoral blood-flow (QL) were determined, and arterial/venous blood samples collected at each workload. Exercise-induced fatigue was estimated via pre/post-exercise changes in quadriceps strength. There were no hemodynamic differences between conditions at rest. During exercise, Q was 8-13% lower with Fentanyl-blockade, secondary to significant reductions in stroke volume and heart rate. Lower norepinephrine spillover during exercise with Fentanyl revealed an attenuated sympathetic outflow that likely contributed to the 25% increase in leg vascular conductance (p<0.05). Despite a concomitant 4% reduction in blood pressure, QL was 10-14% higher and end-exercise fatigue attenuated by 30% with Fentanyl-blockade (p<0.05).

Conclusion/practice/implications: Although group III/IV muscle afferents play a critical role for central hemodynamics in HF-patients, it also appears that these sensory neurons cause excessive sympatho-excitation impairing QL which likely contributes to the exercise intolerance in this population.

Keywords: Autonomic control; Circulation; Exercise pressor reflex; Sensory neurons.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Cardiac-related variables at rest and during exercise. The p-value indicates a significant main effect of fentanyl. *p<0.05, #not different from rest
Figure 2
Figure 2
Hemodynamic responses at rest and during the final minute of exercise. The p-value indicates the overall main effect of fentanyl. *p<0.05
Figure 3
Figure 3
Leg O2 supply and demand at rest and during the final minute of exercise. The p-value indicates the overall main effect of fentanyl. *p<0.05
Figure 4
Figure 4
Exercise-induced reduction in maximal quadriceps voluntary concentration force (MVC) in patients with HF. N=5; *P<0.01
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Adreani CM, Hill JM, Kaufman MP. Responses of group iii and iv muscle afferents to dynamic exercise. J Appl Physiol. 1997;82:1811–1817. - PubMed
    1. Murphy MN, Mizuno M, Mitchell JH, Smith SA. Cardiovascular regulation by skeletal muscle reflexes in health and disease. American journal of physiology. Heart and circulatory physiology. 2011;301:H1191–1204. - PMC - PubMed
    1. Waldrop TG, Eldridge FL, Iwamoto GA, Mitchell JH. Central neural control of respiration and circulation during exercise. In: Rowell LB, Shepherd JT, editors. Handbook of physiology section 12: Exercise: Regulation and integration of multiple systems. New York: Oxford University Press; 1996. pp. 333–380.
    1. Amann M, Runnels S, Morgan DE, Trinity JD, Fjeldstad AS, Wray DW, Reese VR, Richardson RS. On the contribution of group iii and iv muscle afferents to the circulatory response to rhythmic exercise in humans. The Journal of physiology. 2011;589:3855–3866. - PMC - PubMed
    1. Amann M, Blain GM, Proctor LT, Sebranek JJ, Pegelow DF, Dempsey JA. Group iii and iv muscle afferents contribute to ventilatory and cardiovascular response to rhythmic exercise in humans. J Appl Physiol. 2010;109:966–976. - PMC - PubMed

Publication types