Related Experiment Video
Updated: Feb 3, 2026
07:52
Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
17.0K
Optimization of Vagal Stimulation Protocol Based on Spontaneous Breathing Rate
Liliane Appratto De Souza1, Janaina Barcellos Ferreira2, Andressa Silveira de Oliveira Schein1
1Institute of Cardiology of Rio Grande do Sul, University Foundation of Cardiology, Porto Alegre, Brazil.
Frontiers in Physiology
|October 16, 2018
Summary
Controlled breathing can improve vagal tone, but results vary. Normalizing breathing rates to an individual’s spontaneous breathing rate (SBR) consistently enhances vagal modulation, suggesting personalized protocols are key for effective cardiac autonomic control.
Area of Science:
- Cardiovascular physiology
- Autonomic nervous system function
- Respiratory regulation
Background:
- Controlled breathing maneuvers are used to assess cardiovascular autonomic control and activate the vagal system.
- Existing protocols yield inconsistent results, possibly due to individual differences in baseline sympathetic tone.
Purpose of the Study:
- To investigate the impact of controlled breathing on cardiovascular autonomic control.
- To compare standard breathing rate protocols with individualized, normalized rates.
Main Methods:
- Twenty-six healthy subjects participated in two protocols: fixed breathing rates (10, 15, 20 breaths/min) and normalized rates (100%, 80%, 70%, 50% of spontaneous breathing rate).
- Cardiovascular autonomic responses were evaluated.
Main Results:
- Lower breathing rates generally favored vagal modulation.
- A normalized breathing rate of 80% (0.8 * SBR) significantly increased vagal modulation across all participants (HFnu 80 = 67.5% vs. 48.2%, p < 0.0001).
- Standard protocols showed variable vagal activation, unlike the normalized protocol.
Conclusions:
- Controlled breathing protocols aiming for vagal activation should incorporate individual spontaneous breathing rates.
- Using normalized breathing rates, specifically around 80% of SBR, offers a more reliable method for enhancing cardiac vagal tone.
Keywords:
autonomic nervous systemcontrolled breathingheart rate variabilityspectral analysisvagal stimulationMore Related Videos
Related Concept Videos
02:21Spontaneity
30.0K
A spontaneous process is one that occurs naturally under certain conditions. A nonspontaneous process, on the other hand, will not take place unless it is “driven” by the continual input of energy from an external source. Processes have a natural tendency to occur in one direction under a given set of conditions. Water will naturally flow downhill (spontaneous process), but uphill flow (nonspontaneous process) requires outside intervention such as the use of a pump. Iron exposed to...
30.0K
01:05Breathing
64.5K
The process of breathing, inhaling and exhaling, involves the coordinated movement of the chest wall, the lungs, and the muscles that move them. Two muscle groups with important roles in breathing are the diaphragm, located directly below the lungs, and the intercostal muscles, which lie between the ribs. When the diaphragm contracts, it moves downward, increasing the volume of the thoracic cavity and creating more room for the lungs to expand. When the intercostal muscles contract, the ribs...
64.5K
02:53Reaction Rate
63.3K
The rate of reaction is the change in the amount of a reactant or product per unit time. Reaction rates are therefore determined by measuring the time dependence of some property that can be related to reactant or product amounts. Rates of reactions that consume or produce gaseous substances, for example, are conveniently determined by measuring changes in volume or pressure.
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
63.3K
01:30Mechanism of Breathing I: Inspiration
3.2K
Introduction to Inspiration: The Respiratory System in Action
The respiratory system, an essential network for breathing, comprises the conducting and respiratory zones, each playing a crucial role in the overall process of respiration. Let us explore the detailed mechanism of inspiration, or inhalation, which is the first phase of the respiratory cycle.
Pathway of Air during Inspiration
During inspiration, air enters our body through the nose or mouth and moves through the conducting zone,...
The respiratory system, an essential network for breathing, comprises the conducting and respiratory zones, each playing a crucial role in the overall process of respiration. Let us explore the detailed mechanism of inspiration, or inhalation, which is the first phase of the respiratory cycle.
Pathway of Air during Inspiration
During inspiration, air enters our body through the nose or mouth and moves through the conducting zone,...
3.2K
01:23Mechanism of Breathing II: Expiration
2.0K
The Physiology of Expiration: A Seamless Respiratory Process
Expiration, or exhaling, is a complex physiological process that begins as the inspiratory muscles begin to relax. This relaxation triggers a series of events that epitomize the efficiency of the respiratory system.
Mechanism of Expiration:
Expiration, or exhaling, is a complex physiological process that begins as the inspiratory muscles begin to relax. This relaxation triggers a series of events that epitomize the efficiency of the respiratory system.
Mechanism of Expiration:
2.0K
01:30Spontaneous and Induced Mutations
2.3K
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
2.3K