Limits...
Evolution of cardiorespiratory interactions with age.

Iatsenko D, Bernjak A, Stankovski T, Shiogai Y, Owen-Lynch PJ, Clarkson PB, McClintock PV, Stefanovska A - Philos Trans A Math Phys Eng Sci (2013)

Bottom Line: We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90.By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure.We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Lancaster University, Lancaster LA1 4YB, UK.

ABSTRACT
We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90. By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure. By treating the heart and respiration as coupled oscillators, we then apply a method based on Bayesian inference to find the underlying coupling parameters and their time dependence, deriving from them measures such as synchronization, coupling directionality and the relative contributions of different mechanisms. We report a detailed analysis of the reconstructed cardiorespiratory coupling function, its time evolution and age dependence. We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.

Show MeSH

Related in: MedlinePlus

Age dependence of the relative duration of cardiorespiratory synchronization, i.e. the proportion of the measurement time within which there was synchronization at particular ratios: (a) summary of results for each n:m synchronization ratio, age and gender; (b) overall synchronization duration, i.e. the sum of durations for each ratio; (c) average synchronization duration at each ratio, taken over all males, all females and the merged group; note that it is the mean, unlike the median in all other panels: the corresponding median is zero for all ratios except 4:1; (d) the same as (a), but for each synchronization ratio separately; ρ and p are not shown, but there are no significant monotonic correlations for any ratio. (Online version in colour.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4042892&req=5

RSTA20110622F5: Age dependence of the relative duration of cardiorespiratory synchronization, i.e. the proportion of the measurement time within which there was synchronization at particular ratios: (a) summary of results for each n:m synchronization ratio, age and gender; (b) overall synchronization duration, i.e. the sum of durations for each ratio; (c) average synchronization duration at each ratio, taken over all males, all females and the merged group; note that it is the mean, unlike the median in all other panels: the corresponding median is zero for all ratios except 4:1; (d) the same as (a), but for each synchronization ratio separately; ρ and p are not shown, but there are no significant monotonic correlations for any ratio. (Online version in colour.)

Mentions: Figure 5a summarizes all the information about synchronization obtained in this way, in the form of the relative synchronization duration, i.e. the proportion of the time during which the signals were synchronized at a particular n:m ratio. Note that, because synchronization is quantized in 50 s intervals, the results do not take into account possible shorter episodes of synchronization. Therefore, in general, the relative synchronization duration will actually be higher. Second, the calculated overall synchronization duration relates only to the particular synchronization ratios considered, taking no account of, for example, 9:1 synchronization. As can be seen, however, even the 6:1 and 7:1 ratios are quite rare, whereas the most prevalent ratio is usually 4:1 (figure 5c).Figure 5.


Evolution of cardiorespiratory interactions with age.

Iatsenko D, Bernjak A, Stankovski T, Shiogai Y, Owen-Lynch PJ, Clarkson PB, McClintock PV, Stefanovska A - Philos Trans A Math Phys Eng Sci (2013)

Age dependence of the relative duration of cardiorespiratory synchronization, i.e. the proportion of the measurement time within which there was synchronization at particular ratios: (a) summary of results for each n:m synchronization ratio, age and gender; (b) overall synchronization duration, i.e. the sum of durations for each ratio; (c) average synchronization duration at each ratio, taken over all males, all females and the merged group; note that it is the mean, unlike the median in all other panels: the corresponding median is zero for all ratios except 4:1; (d) the same as (a), but for each synchronization ratio separately; ρ and p are not shown, but there are no significant monotonic correlations for any ratio. (Online version in colour.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4042892&req=5

RSTA20110622F5: Age dependence of the relative duration of cardiorespiratory synchronization, i.e. the proportion of the measurement time within which there was synchronization at particular ratios: (a) summary of results for each n:m synchronization ratio, age and gender; (b) overall synchronization duration, i.e. the sum of durations for each ratio; (c) average synchronization duration at each ratio, taken over all males, all females and the merged group; note that it is the mean, unlike the median in all other panels: the corresponding median is zero for all ratios except 4:1; (d) the same as (a), but for each synchronization ratio separately; ρ and p are not shown, but there are no significant monotonic correlations for any ratio. (Online version in colour.)
Mentions: Figure 5a summarizes all the information about synchronization obtained in this way, in the form of the relative synchronization duration, i.e. the proportion of the time during which the signals were synchronized at a particular n:m ratio. Note that, because synchronization is quantized in 50 s intervals, the results do not take into account possible shorter episodes of synchronization. Therefore, in general, the relative synchronization duration will actually be higher. Second, the calculated overall synchronization duration relates only to the particular synchronization ratios considered, taking no account of, for example, 9:1 synchronization. As can be seen, however, even the 6:1 and 7:1 ratios are quite rare, whereas the most prevalent ratio is usually 4:1 (figure 5c).Figure 5.

Bottom Line: We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90.By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure.We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Lancaster University, Lancaster LA1 4YB, UK.

ABSTRACT
We describe an analysis of cardiac and respiratory time series recorded from 189 subjects of both genders aged 16-90. By application of the synchrosqueezed wavelet transform, we extract the respiratory and cardiac frequencies and phases with better time resolution than is possible with the marked events procedure. By treating the heart and respiration as coupled oscillators, we then apply a method based on Bayesian inference to find the underlying coupling parameters and their time dependence, deriving from them measures such as synchronization, coupling directionality and the relative contributions of different mechanisms. We report a detailed analysis of the reconstructed cardiorespiratory coupling function, its time evolution and age dependence. We show that the direct and indirect respiratory modulations of the heart rate both decrease with age, and that the cardiorespiratory coupling becomes less stable and more time-variable.

Show MeSH
Related in: MedlinePlus