What is the clinical evidence from this study?

Study design: Observational. Population: Respiratory sinus arrhythmia (n=18). Intervention: Passive positive pressure ventilation vs. Voluntary (active) ventilation. Primary outcome: Respiratory sinus arrhythmia (beats/min).

What question did this study set out to answer?

This study investigates the role of vagal feedback from the lungs in generating respiratory sinus arrhythmia in humans.

February 1, 1995Journal of Applied Physiology

Respiratory sinus arrhythmia in humans: an obligatory role for vagal feedback from the lungs

View Full Paper

Ask AI

Bookmark

Key result

Passive positive pressure ventilation reduced respiratory sinus arrhythmia from 11 +/- 2.2 beats/min during active ventilation to 5.4 +/- 0.8 beats/min in normal subjects.

Why the study?

Does vagal feedback from the lungs play an obligatory role in generating respiratory sinus arrhythmia in humans?

Key Points

This study investigates the role of vagal feedback from the lungs in generating respiratory sinus arrhythmia in humans.
Compared RSA in lung-denervated patients with intact hearts to normal controls and other transplant patients at matched tidal volumes and frequencies.
Examined RSA responses during voluntary and passive ventilation at normocapnia in normal subjects.
In normal and liver transplant subjects, RSA increased significantly with tidal volume and effort, showing normal vagal responses.
In heart- and lung-denervated subjects, RSA was only 53% of normal during eupnea and did not respond to tidal volume changes.
RSA reduced from 11 beats/min during active to 5.4 beats/min during passive ventilation in normal subjects.

Study Design

Type

Observational (n=18)

Structured PICO

Does vagal feedback from the lungs play an obligatory role in generating respiratory sinus arrhythmia in humans?

Population

18 subjects including 5 lung-denervated double-lung transplant patients with intact hearts, 6 normal control subjects, 5 heart-denervated patients, and 2 liver transplant patients

Intervention

Assessment of respiratory sinus arrhythmia during eupnea, varying tidal volumes, inspiratory effort, and breathing frequencies, as well as during voluntary (active) versus passive positive pressure ventilation

Comparator

Normal control subjects and liver transplant patients at matched tidal volumes and breathing frequencies

Outcome

Magnitude of respiratory sinus arrhythmia (RSA)surrogate

Main Result

Absolute Event Rate: 5.4% vs 11%

Vagal feedback from pulmonary stretch receptors is obligatory for generating neurally mediated respiratory sinus arrhythmia in awake humans.

Discussion

No takes yet. Share an insight, caveat, or question.

Implication

Supports obligatory pulmonary vagal feedback in RSA; leaves open generalizability to cardiopulmonary disease.

Cite This Study

Taha et al. (1995) conducted an observational in Respiratory sinus arrhythmia (n=18). Passive positive pressure ventilation vs. Voluntary (active) ventilation was evaluated on Respiratory sinus arrhythmia (beats/min). Passive positive pressure ventilation reduced respiratory sinus arrhythmia from 11 +/- 2.2 beats/min during active ventilation to 5.4 +/- 0.8 beats/min in normal subjects.

synapsesocial.com/papers/6a0f9de7d03631df9ce9cd32 https://doi.org/10.1152/jappl.1995.78.2.638

Topics

Heart transplantation

View Full Paper

Ask AI

Bookmark

Respiratory sinus arrhythmia in humans: an obligatory role for vagal feedback from the lungs

Key Points

Study Design

Structured PICO

Main Result

Discussion

Implication

Cite This Study

Topics

Respiratory sinus arrhythmia in humans: an obligatory role for vagal feedback from the lungs

Key Points

Study Design

Structured PICO

Main Result

Discussion

Implication

Cite This Study

Also Consider

Topics

Also Consider