Related Experiment Video
Updated: Aug 19, 2026
Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
The determination of cardioventilatory coupling from heart rate and ventilatory time series
1Wellington School of Medicine, P.O. Box 7343, Wellington, New Zealand. surgdg@wnmeds.ac.nz
Abstract:
In 35 anaesthetised human subjects, we examined the effect of cardioventilatory coupling on R-R interval and ventilatory period time series. We observed that, in the presence of coupling: (a) ventilatory period fluctuated in a quantal manner, each quantal step corresponding to a multiple (or a little less) of the heart period; (b) heart period fluctuations, associated with respiratory sinus arrythmia, were identical for consecutive ventilatory periods. The regularity of heart period variation lead to geometric patterning of raw R-R time series, R-R consecutive difference time series, the phase portrait (R-R(n) vs R-R(n+1)) and the map of R-R interval variation (DeltaR-R(n) vs DeltaR-R(n+1)). These geometric features may be useful for the determination of cardioventilatory coupling from heart rate time series.
Related Concept Videos
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
01:29Assessment of Ventilation II: Respiratory Depth and Rhythm
Respiratory depth measures the volume of air inhaled or exhaled during a breath. It can vary from shallow to deep and typically remains consistent when a person is at rest or asleep. Occasionally, individuals will automatically inhale deeply, known as sighing, which inflates the lungs with more air than normal breathing.
To assess respiratory depth, observe the degree of chest excursion or movement:
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:19Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
01:14Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...