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Periodic Breathing in Heart Failure Explained by Dynamic and Static Properties of Respiratory Control.

Miyamoto T, Nakahara H, Ueda S, Manabe K, Kawai E, Inagaki M, Kawada T, Sugimachi M - Clin Med Insights Cardiol (2015)

Bottom Line: In healthy volunteers, we measured arterial CO2 partial pressure (PaCO2) and minute ventilation [Formula: see text] to estimate the dynamic properties of the controller ( [Formula: see text] relation) and plant ( [Formula: see text] relation).The dynamic properties of the controller and plant approximated first- and second-order exponential models, respectively, and were described using parameters including gain, time constant, and lag time.We then used the open-loop transfer functions to simulate the closed-loop respiratory response to an exogenous disturbance, while manipulating the parameter values to deviate from normal values but within physiological ranges.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Health Sciences, Morinomiya University of Medical Sciences, Osaka City, Osaka, Japan.

ABSTRACT

Objective: The respiratory operating point is determined by the interplay between the controller and plant subsystem elements within the respiratory chemoreflex feedback system. This study aimed to establish the methodological basis for quantitative analysis of the open-loop dynamic properties of the human respiratory control system and to apply the results to explore detailed mechanisms of the regulation of respiration and the possible mechanism of periodic breathing in chronic heart failure.

Methods and results: In healthy volunteers, we measured arterial CO2 partial pressure (PaCO2) and minute ventilation [Formula: see text] to estimate the dynamic properties of the controller ( [Formula: see text] relation) and plant ( [Formula: see text] relation). The dynamic properties of the controller and plant approximated first- and second-order exponential models, respectively, and were described using parameters including gain, time constant, and lag time. We then used the open-loop transfer functions to simulate the closed-loop respiratory response to an exogenous disturbance, while manipulating the parameter values to deviate from normal values but within physiological ranges. By increasing both the product of gains of the two subsystem elements (total loop gain) and the lag time, the condition of system oscillation (onset of periodic breathing) was satisfied.

Conclusion: When abnormality occurs in a part of the respiratory chemoreflex system, instability of the control system is amplified and may result in the manifestation of respiratory abnormalities such as periodic breathing.

No MeSH data available.


Related in: MedlinePlus

Simulations of changes in minute ventilation  over time when a one-step perturbation (step load in arterial CO2 partial pressure: PaCO2 = 5 mmHg) was imposed on a biological closed feedback loop, using the open-loop transfer functions determined in this study. In the simulation, when the system gain (up to three-fold increase) and lag time (prolongation up to 20 seconds) are both increased within a physiologically relevant range, the condition for system oscillation is satisfied and periodic breathing occurs (*oscillation phenomenon).
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f7-cmc-suppl.1-2015-133: Simulations of changes in minute ventilation over time when a one-step perturbation (step load in arterial CO2 partial pressure: PaCO2 = 5 mmHg) was imposed on a biological closed feedback loop, using the open-loop transfer functions determined in this study. In the simulation, when the system gain (up to three-fold increase) and lag time (prolongation up to 20 seconds) are both increased within a physiologically relevant range, the condition for system oscillation is satisfied and periodic breathing occurs (*oscillation phenomenon).

Mentions: Figure 7 illustrates the simulation results showing the time course of in response to a one-step perturbation (step load: PaCO2 = 5 mmHg). Simulations were repeated while changing the dynamic property of the controller by varying the gain and lag time. Because the controller and the plant are serially connected (Fig. 1), changes in the controller gain are proportional to changes in the TG of the system. Increases in TG and lag time from their normal values result in instability of the system, and abnormal findings such as periodic breathing (asterisks in Fig. 7) found in CHF can be observed in these simulations.


Periodic Breathing in Heart Failure Explained by Dynamic and Static Properties of Respiratory Control.

Miyamoto T, Nakahara H, Ueda S, Manabe K, Kawai E, Inagaki M, Kawada T, Sugimachi M - Clin Med Insights Cardiol (2015)

Simulations of changes in minute ventilation  over time when a one-step perturbation (step load in arterial CO2 partial pressure: PaCO2 = 5 mmHg) was imposed on a biological closed feedback loop, using the open-loop transfer functions determined in this study. In the simulation, when the system gain (up to three-fold increase) and lag time (prolongation up to 20 seconds) are both increased within a physiologically relevant range, the condition for system oscillation is satisfied and periodic breathing occurs (*oscillation phenomenon).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4629632&req=5

f7-cmc-suppl.1-2015-133: Simulations of changes in minute ventilation over time when a one-step perturbation (step load in arterial CO2 partial pressure: PaCO2 = 5 mmHg) was imposed on a biological closed feedback loop, using the open-loop transfer functions determined in this study. In the simulation, when the system gain (up to three-fold increase) and lag time (prolongation up to 20 seconds) are both increased within a physiologically relevant range, the condition for system oscillation is satisfied and periodic breathing occurs (*oscillation phenomenon).
Mentions: Figure 7 illustrates the simulation results showing the time course of in response to a one-step perturbation (step load: PaCO2 = 5 mmHg). Simulations were repeated while changing the dynamic property of the controller by varying the gain and lag time. Because the controller and the plant are serially connected (Fig. 1), changes in the controller gain are proportional to changes in the TG of the system. Increases in TG and lag time from their normal values result in instability of the system, and abnormal findings such as periodic breathing (asterisks in Fig. 7) found in CHF can be observed in these simulations.

Bottom Line: In healthy volunteers, we measured arterial CO2 partial pressure (PaCO2) and minute ventilation [Formula: see text] to estimate the dynamic properties of the controller ( [Formula: see text] relation) and plant ( [Formula: see text] relation).The dynamic properties of the controller and plant approximated first- and second-order exponential models, respectively, and were described using parameters including gain, time constant, and lag time.We then used the open-loop transfer functions to simulate the closed-loop respiratory response to an exogenous disturbance, while manipulating the parameter values to deviate from normal values but within physiological ranges.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Health Sciences, Morinomiya University of Medical Sciences, Osaka City, Osaka, Japan.

ABSTRACT

Objective: The respiratory operating point is determined by the interplay between the controller and plant subsystem elements within the respiratory chemoreflex feedback system. This study aimed to establish the methodological basis for quantitative analysis of the open-loop dynamic properties of the human respiratory control system and to apply the results to explore detailed mechanisms of the regulation of respiration and the possible mechanism of periodic breathing in chronic heart failure.

Methods and results: In healthy volunteers, we measured arterial CO2 partial pressure (PaCO2) and minute ventilation [Formula: see text] to estimate the dynamic properties of the controller ( [Formula: see text] relation) and plant ( [Formula: see text] relation). The dynamic properties of the controller and plant approximated first- and second-order exponential models, respectively, and were described using parameters including gain, time constant, and lag time. We then used the open-loop transfer functions to simulate the closed-loop respiratory response to an exogenous disturbance, while manipulating the parameter values to deviate from normal values but within physiological ranges. By increasing both the product of gains of the two subsystem elements (total loop gain) and the lag time, the condition of system oscillation (onset of periodic breathing) was satisfied.

Conclusion: When abnormality occurs in a part of the respiratory chemoreflex system, instability of the control system is amplified and may result in the manifestation of respiratory abnormalities such as periodic breathing.

No MeSH data available.


Related in: MedlinePlus