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Locomotor muscle group III/IV afferents constrain stroke volume and contribute to exercise intolerance in human heart failure
- Source :
- The Journal of Physiology. 598:5379-5390
- Publication Year :
- 2020
- Publisher :
- Wiley, 2020.
-
Abstract
- KEY POINTS Heart failure patients with reduced ejection fraction (HFrEF) exhibit severe limitations in exercise capacity ( VO2 peak). One of the primary peripheral mechanisms suggested to underlie exercise intolerance in HFrEF is excessive locomotor muscle group III/IV afferent feedback; however, this has never been investigated in human heart failure. HFrEF patients and controls performed an incremental exercise test to volitional exhaustion to determine VO2 peak with lumbar intrathecal fentanyl or placebo. During exercise, cardiac output, leg blood flow and radial artery and femoral venous blood gases were measured. With fentanyl, compared with placebo, patients with HFrEF achieved a higher peak workload, VO2 peak, cardiac output, stroke volume and leg blood flow. These findings suggest that locomotor muscle group III/IV afferent feedback in HFrEF leads to increased systemic vascular resistance, which constrains stroke volume, cardiac output and O2 delivery thereby impairing VO2 peak and thus exercise capacity. ABSTRACT To better understand the underlying mechanisms contributing to exercise limitation in heart failure with reduced ejection fraction (HFrEF), we investigated the influence of locomotor muscle group III/IV afferent inhibition via lumbar intrathecal fentanyl on peak exercise capacity ( VO2 peak) and the contributory mechanisms. Eleven HFrEF patients and eight healthy matched controls were recruited. The participants performed an incremental exercise test to volitional exhaustion to determine VO2 peak with lumbar intrathecal fentanyl or placebo. During exercise, cardiac output and leg blood flow ( QL ) were measured via open-circuit acetylene wash-in technique and constant infusion thermodilution, respectively. Radial artery and femoral venous blood gases were measured. VO2 peak was 15% greater with fentanyl compared with placebo for HFrEF (P
- Subjects :
- 0301 basic medicine
medicine.medical_specialty
Cardiac output
Physiology
Exercise intolerance
Incremental exercise
03 medical and health sciences
Oxygen Consumption
0302 clinical medicine
Internal medicine
Humans
Medicine
Muscle, Skeletal
Exercise
Heart Failure
Ejection fraction
business.industry
Stroke Volume
Stroke volume
Venous blood
medicine.disease
Fentanyl
030104 developmental biology
medicine.anatomical_structure
Heart failure
Vascular resistance
Cardiology
medicine.symptom
business
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 14697793 and 00223751
- Volume :
- 598
- Database :
- OpenAIRE
- Journal :
- The Journal of Physiology
- Accession number :
- edsair.doi.dedup.....2618afc4e59ef1a0a95f6cc432b7c32d