Sympathetic neural responses in heart failure during exercise and after exercise training

Area of Science:

• Cardiovascular Physiology
• Neuroscience
• Exercise Science

Background:

• Sympathetic nervous system (SNS) regulates cardiovascular responses during exercise.
• SNS regulation is impaired in heart failure with reduced ejection fraction (HFrEF), leading to sympathoexcitation.
• This sympathoexcitation limits exercise capacity and worsens prognosis in HFrEF.

Purpose of the Study:

• To review sympathetic nerve activity during exercise in HFrEF.
• To summarize the effects of exercise training on sympathetic outflow in HFrEF.
• To highlight studies using direct intraneural recordings of sympathetic nerve traffic.

Main Methods:

• Review of experimental and human studies on sympathetic activity during exercise in HFrEF.
• Analysis of factors influencing sympathetic responses to exercise.
• Synthesis of data on exercise training interventions and their impact on sympathetic outflow.

Main Results:

• Sympathetic activity is altered during various exercise modes in HFrEF.
• Exercise training can modulate sympathetic excess at rest and during exercise in HFrEF.
• Direct measurements of sympathetic nerve traffic during exercise in HFrEF are limited but informative.

Conclusions:

• Understanding sympathetic responses to exercise in HFrEF is crucial.
• Exercise training shows potential in mitigating sympathetic overdrive in HFrEF.
• Further research is needed on afferent mechanisms and the impact of attenuated sympathetic activity.