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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

Typical dynamic properties (transient response properties) of the controller (A) and the plant (B) in the respiratory chemoreflex system. Arterial blood was collected one minute before and 11 minutes after the one-step intervention, and the arterial CO2 partial pressure (PaCO2) measured from each individual was used to calibrate the continuous end-tidal CO2 partial pressure (PETCO2) data and to obtain estimated PaCO2 (estPaCO2). In panel A, the controller property ( relation) can be approximated by a first-order low-pass filter (the gray smooth line). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119. ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg. In panel B, the plant element ( relation) can be approximated by a second-order low-pass filter (the gray smooth line), showing a biphasic response with a rapid decline in the initial phase of step loading followed by a gradual decrease. The coefficients were estimated as follows: estPaCO2(0); 44.3 ± 1.9 mmHg, gain Gv1; −0.6 ± 0.3 mmHg L−1 minute, gain Gv2; −1.1 ± 0.6 mmHg L−1 minute, lag time Lv1: 0.8 ± 1.1 seconds; lag time Lv2; 0.5 ± 0.6 seconds; time constant τv1; 11.9 ± 10.9 seconds, time constant τv2; 214 ± 101 seconds.
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f5-cmc-suppl.1-2015-133: Typical dynamic properties (transient response properties) of the controller (A) and the plant (B) in the respiratory chemoreflex system. Arterial blood was collected one minute before and 11 minutes after the one-step intervention, and the arterial CO2 partial pressure (PaCO2) measured from each individual was used to calibrate the continuous end-tidal CO2 partial pressure (PETCO2) data and to obtain estimated PaCO2 (estPaCO2). In panel A, the controller property ( relation) can be approximated by a first-order low-pass filter (the gray smooth line). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119. ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg. In panel B, the plant element ( relation) can be approximated by a second-order low-pass filter (the gray smooth line), showing a biphasic response with a rapid decline in the initial phase of step loading followed by a gradual decrease. The coefficients were estimated as follows: estPaCO2(0); 44.3 ± 1.9 mmHg, gain Gv1; −0.6 ± 0.3 mmHg L−1 minute, gain Gv2; −1.1 ± 0.6 mmHg L−1 minute, lag time Lv1: 0.8 ± 1.1 seconds; lag time Lv2; 0.5 ± 0.6 seconds; time constant τv1; 11.9 ± 10.9 seconds, time constant τv2; 214 ± 101 seconds.

Mentions: In the first experiment, we measured est.PaCO2, VT, and RR in response to a one-step increase in FICO2. was calculated from the product of VT and RR, and estPaCO2 was estimated by continuous PETCO2 and PaCO2 relations. By inspiring the CO2-containing gas, estPaCO2 also showed a corresponding one-step increase and was accompanied by increases in VT and RR in both the representative case (Fig. 4A) and pooled data (Fig. 4B). As a result, increased in an exponential manner. The step response can be approximated by a first-order low-pass filter (r2 = 0.749 ± 0.17, ranging from 0.479 to 0.926) (Fig. 5A). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119 ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg.


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)

Typical dynamic properties (transient response properties) of the controller (A) and the plant (B) in the respiratory chemoreflex system. Arterial blood was collected one minute before and 11 minutes after the one-step intervention, and the arterial CO2 partial pressure (PaCO2) measured from each individual was used to calibrate the continuous end-tidal CO2 partial pressure (PETCO2) data and to obtain estimated PaCO2 (estPaCO2). In panel A, the controller property ( relation) can be approximated by a first-order low-pass filter (the gray smooth line). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119. ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg. In panel B, the plant element ( relation) can be approximated by a second-order low-pass filter (the gray smooth line), showing a biphasic response with a rapid decline in the initial phase of step loading followed by a gradual decrease. The coefficients were estimated as follows: estPaCO2(0); 44.3 ± 1.9 mmHg, gain Gv1; −0.6 ± 0.3 mmHg L−1 minute, gain Gv2; −1.1 ± 0.6 mmHg L−1 minute, lag time Lv1: 0.8 ± 1.1 seconds; lag time Lv2; 0.5 ± 0.6 seconds; time constant τv1; 11.9 ± 10.9 seconds, time constant τv2; 214 ± 101 seconds.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4629632&req=5

f5-cmc-suppl.1-2015-133: Typical dynamic properties (transient response properties) of the controller (A) and the plant (B) in the respiratory chemoreflex system. Arterial blood was collected one minute before and 11 minutes after the one-step intervention, and the arterial CO2 partial pressure (PaCO2) measured from each individual was used to calibrate the continuous end-tidal CO2 partial pressure (PETCO2) data and to obtain estimated PaCO2 (estPaCO2). In panel A, the controller property ( relation) can be approximated by a first-order low-pass filter (the gray smooth line). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119. ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg. In panel B, the plant element ( relation) can be approximated by a second-order low-pass filter (the gray smooth line), showing a biphasic response with a rapid decline in the initial phase of step loading followed by a gradual decrease. The coefficients were estimated as follows: estPaCO2(0); 44.3 ± 1.9 mmHg, gain Gv1; −0.6 ± 0.3 mmHg L−1 minute, gain Gv2; −1.1 ± 0.6 mmHg L−1 minute, lag time Lv1: 0.8 ± 1.1 seconds; lag time Lv2; 0.5 ± 0.6 seconds; time constant τv1; 11.9 ± 10.9 seconds, time constant τv2; 214 ± 101 seconds.
Mentions: In the first experiment, we measured est.PaCO2, VT, and RR in response to a one-step increase in FICO2. was calculated from the product of VT and RR, and estPaCO2 was estimated by continuous PETCO2 and PaCO2 relations. By inspiring the CO2-containing gas, estPaCO2 also showed a corresponding one-step increase and was accompanied by increases in VT and RR in both the representative case (Fig. 4A) and pooled data (Fig. 4B). As a result, increased in an exponential manner. The step response can be approximated by a first-order low-pass filter (r2 = 0.749 ± 0.17, ranging from 0.479 to 0.926) (Fig. 5A). The coefficients were estimated as follows: ; 10.9 ± 2.1 L minute−1, gain Gu; 2.9 ± 1.8 L minute−1 mmHg−1, lag time Lu; 3.3 ± 4.9 seconds, time constant τu; 119 ± 48 seconds, ∆estPaCO2; 6.7 ± 2.6 mmHg.

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