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Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

Maksuti E, Westerhof N, Westerhof BE, Broomé M, Stergiopulos N - PLoS ONE (2016)

Bottom Line: In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study.Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging.The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.

ABSTRACT
During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well. In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study. Parameters representing arterial changes (resistance and stiffness) during aging were based on literature values, whereas parameters representing cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). When taking into account arterial changes only, the systolic and diastolic pressure did not agree well with the population data. Between 20 and 80 years, systolic pressure increased from 100 to 122 mmHg, and diastolic pressure decreased from 76 to 55 mmHg. When taking cardiac adaptations into account as well, systolic and diastolic pressure increased from 100 to 151 mmHg and decreased from 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging. The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the time-varying elastance model E(t) and the four-element Windkessel model.E(t) varies from its end-diastolic value (Eed) to its end-systolic value (Ees) during the heart period (T). The arterial model includes characteristic impedance (Zc), inertance (L), total arterial compliance (C) and vascular resistance (R). Voltage and current at the beginning of the Windkessel model represent aortic pressure (pAo) and flow (qAo), respectively.
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pone.0157493.g001: Schematic representation of the time-varying elastance model E(t) and the four-element Windkessel model.E(t) varies from its end-diastolic value (Eed) to its end-systolic value (Ees) during the heart period (T). The arterial model includes characteristic impedance (Zc), inertance (L), total arterial compliance (C) and vascular resistance (R). Voltage and current at the beginning of the Windkessel model represent aortic pressure (pAo) and flow (qAo), respectively.

Mentions: The contributions of the arterial system and the heart to aortic blood pressure were quantified using a ventricular-arterial interaction model, previously described and validated [9,12]. A scheme of the model is shown in Fig 1. The systemic arterial tree is represented by the four-element Windkessel model [10], which has as its model parameters total arterial compliance (C) representing the inverse of arterial stiffness, vascular resistance (R), aortic characteristic impedance (Zc) and total inertance (L).


Contribution of the Arterial System and the Heart to Blood Pressure during Normal Aging - A Simulation Study.

Maksuti E, Westerhof N, Westerhof BE, Broomé M, Stergiopulos N - PLoS ONE (2016)

Schematic representation of the time-varying elastance model E(t) and the four-element Windkessel model.E(t) varies from its end-diastolic value (Eed) to its end-systolic value (Ees) during the heart period (T). The arterial model includes characteristic impedance (Zc), inertance (L), total arterial compliance (C) and vascular resistance (R). Voltage and current at the beginning of the Windkessel model represent aortic pressure (pAo) and flow (qAo), respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920393&req=5

pone.0157493.g001: Schematic representation of the time-varying elastance model E(t) and the four-element Windkessel model.E(t) varies from its end-diastolic value (Eed) to its end-systolic value (Ees) during the heart period (T). The arterial model includes characteristic impedance (Zc), inertance (L), total arterial compliance (C) and vascular resistance (R). Voltage and current at the beginning of the Windkessel model represent aortic pressure (pAo) and flow (qAo), respectively.
Mentions: The contributions of the arterial system and the heart to aortic blood pressure were quantified using a ventricular-arterial interaction model, previously described and validated [9,12]. A scheme of the model is shown in Fig 1. The systemic arterial tree is represented by the four-element Windkessel model [10], which has as its model parameters total arterial compliance (C) representing the inverse of arterial stiffness, vascular resistance (R), aortic characteristic impedance (Zc) and total inertance (L).

Bottom Line: In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study.Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging.The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Engineering, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.

ABSTRACT
During aging, systolic blood pressure continuously increases over time, whereas diastolic pressure first increases and then slightly decreases after middle age. These pressure changes are usually explained by changes of the arterial system alone (increase in arterial stiffness and vascular resistance). However, we hypothesise that the heart contributes to the age-related blood pressure progression as well. In the present study we quantified the blood pressure changes in normal aging by using a Windkessel model for the arterial system and the time-varying elastance model for the heart, and compared the simulation results with data from the Framingham Heart Study. Parameters representing arterial changes (resistance and stiffness) during aging were based on literature values, whereas parameters representing cardiac changes were computed through physiological rules (compensated hypertrophy and preservation of end-diastolic volume). When taking into account arterial changes only, the systolic and diastolic pressure did not agree well with the population data. Between 20 and 80 years, systolic pressure increased from 100 to 122 mmHg, and diastolic pressure decreased from 76 to 55 mmHg. When taking cardiac adaptations into account as well, systolic and diastolic pressure increased from 100 to 151 mmHg and decreased from 76 to 69 mmHg, respectively. Our results show that not only the arterial system, but also the heart, contributes to the changes in blood pressure during aging. The changes in arterial properties initiate a systolic pressure increase, which in turn initiates a cardiac remodelling process that further augments systolic pressure and mitigates the decrease in diastolic pressure.

No MeSH data available.


Related in: MedlinePlus