Related Experiment Video
Updated: Aug 15, 2026
06:30
Quantifying Acute Changes in Renal Sympathetic Nerve Activity in Response to Central Nervous System Manipulations in Anesthetized Rats
Published on: September 11, 2018
Cardiac sympathetic afferent reflexes in heart failure
1Department of Physiology and Biophysics, University of Nebraska College of Medicine, Omaha, NE 68198-4575, USA. wwang@molbio.unmc.edu
Heart Failure Reviews
|October 18, 2005
Summary
In heart failure, the cardiac sympathetic afferent reflex is heightened, contributing to increased sympathetic nerve activity. Understanding this reflex offers new therapeutic targets for heart failure management.
Area of Science:
- Cardiovascular physiology
- Neuroscience
- Heart failure research
Background:
- Heart failure is associated with increased sympathetic nervous system activity.
- The precise mechanisms driving this sympatho-excitation remain unclear.
- Previous research suggests a role for cardiac afferent pathways.
Purpose of the Study:
- To investigate the cardiac sympathetic afferent reflex in heart failure.
- To determine the contribution of tonic cardiac sympathetic afferent inputs to elevated sympathetic tone.
- To explore the central mechanisms underlying reflex sensitization in heart failure.
Main Methods:
- Comparison of cardiac sympathetic afferent reflex activity between healthy dogs and dogs with pacing-induced heart failure.
- Assessment of tonic sympathetic afferent inputs.
- Evaluation of central gain and neurochemical modulation (angiotensin II and nitric oxide).
Main Results:
- The cardiac sympathetic afferent reflex is augmented in heart failure.
- Tonic cardiac sympathetic afferent inputs significantly contribute to elevated sympathetic tone.
- Cardiac sympathetic afferents exhibit sensitization in heart failure.
- Central gain of the reflex is sensitized, potentially due to increased central Ang II and reduced NO.
Conclusions:
- The augmented cardiac sympathetic afferent reflex plays a key role in sympathetic activation during heart failure.
- Sensitization of this reflex involves both peripheral and central mechanisms.
- Targeting the neuro-humoral regulation of this reflex may lead to improved therapies for heart failure.
Related Concept Videos
01:29Heart Failure II: Pathophysiology
Systolic Heart Failure and Compensatory MechanismsSystolic heart failure (also termed HFrEF, Heart Failure with Reduced Ejection Fraction) is the most prevalent type of heart filure. It results in a decreased volume of blood being pumped from the ventricle. The aortic arch and carotid sinuses have baroreceptors that detect reduced blood pressure, triggering the sympathetic nervous system (SNS) to release epinephrine and norepinephrine. Initially, this response aims to boost heart rate and...
01:26Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...
01:17Pathophysiology of Heart Failure
Heart failure (HF) is a progressive syndrome involving ventricles that leads to inadequate cardiac output. It can be classified based on location and output or ejection fraction. Ejection fraction (EF) is an essential measurement in the diagnosis and surveillance of HF. Reduced EF corresponds to systolic heart failure (HFrEF). However, HF with preserved ejection fraction (HFpEF) is becoming increasingly prevalent. Also known as diastolic HF, this form of HF is related to aging. The...
01:22Heart Failure Drugs: β-Blockers
β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation, vasodilation, and...
01:27Heart Failure I: Introduction
Heart failure refers to a clinical syndrome caused by structural or functional cardiac disorders that prevent the heart from pumping an adequate amount of blood to meet the body's metabolic needs. This condition often arises from myocardial infarction or ischemia, leading to decreased cardiac output, reduced tissue perfusion, impaired gas exchange, fluid volume imbalance, and decreased functional ability.Heart failure can result from disruptions in the mechanisms that regulate cardiac output...
01:30Heart Failure VII: Nursing Interventions
The first step in nursing management of a patient with heart failure involves thoroughly assessing the patient's medical history.Subjective Data: Obtain the patient's medical history of coronary artery disease, hypertension, myocardial infarction, and symptoms like dyspnea, orthopnea, and paroxysmal nocturnal dyspnea.Objective Data: Conduct a physical examination to identify findings such as jugular vein distention, pulmonary crackles, tachycardia, murmurs, peripheral edema, and vital signs,...