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Closing the loop: modelling of heart failure progression from health to end-stage using a meta-analysis of left ventricular pressure-volume loops.

Warriner DR, Brown AG, Varma S, Sheridan PJ, Lawford P, Hose DR, Al-Mohammad A, Shi Y - PLoS ONE (2014)

Bottom Line: The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification.The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF.

View Article: PubMed Central - PubMed

Affiliation: Medical Physics Group, Department of Cardiovascular Science, University of Sheffield, Sheffield, S10 2TN, United Kingdom; Department of Cardiology, Northern General Hospital, Sheffield Teaching Hospitals, Sheffield, S5 7AU, United Kingdom.

ABSTRACT

Introduction: The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models.

Methods and results: A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).

Conclusions: For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.

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Related in: MedlinePlus

Schematic diagram of Zero-D model of the cardiovascular system, with the heart comprised of variable capacitors representing elastance of the LA (ELA) and LV (ELV) and the aortic (ao) and mitral valves (mi) by diodes.The systemic loop is comprised of a systemic arterial compliance represented by a capacitor (CV) and total peripheral resistance by a resistor (RV).
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pone-0114153-g004: Schematic diagram of Zero-D model of the cardiovascular system, with the heart comprised of variable capacitors representing elastance of the LA (ELA) and LV (ELV) and the aortic (ao) and mitral valves (mi) by diodes.The systemic loop is comprised of a systemic arterial compliance represented by a capacitor (CV) and total peripheral resistance by a resistor (RV).

Mentions: For this study, a lumped parameter model with a variable elastance LV and 2 element (R and C) Windkessel afterload was chosen to model the LV in LVSD-HF [40]. It was chosen due to its elegance in representing the cardiovascular system, simplicity in manipulation, low computational demands and experience within the research group. This was downloaded from the CellML (http://www.cellml.org/) model repository, which is a free to access store of computer based mathematical models, and run using OpenCell, an open source platform for working with CellML models, see figure 4[41]. In this model the left atrium (ELA) and left ventricle (ELV) are represented by variable capacitors to model the pumping action of the left side of the heart, the mitral (mi) and aortic (ao) valves are represented by diodes to model unidirectional flow, the total peripheral resistance by a resistor, systemic vascular compliance by a capacitor and blood vessels by wire allowing for flow of electrons, representing the flow of blood.


Closing the loop: modelling of heart failure progression from health to end-stage using a meta-analysis of left ventricular pressure-volume loops.

Warriner DR, Brown AG, Varma S, Sheridan PJ, Lawford P, Hose DR, Al-Mohammad A, Shi Y - PLoS ONE (2014)

Schematic diagram of Zero-D model of the cardiovascular system, with the heart comprised of variable capacitors representing elastance of the LA (ELA) and LV (ELV) and the aortic (ao) and mitral valves (mi) by diodes.The systemic loop is comprised of a systemic arterial compliance represented by a capacitor (CV) and total peripheral resistance by a resistor (RV).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257583&req=5

pone-0114153-g004: Schematic diagram of Zero-D model of the cardiovascular system, with the heart comprised of variable capacitors representing elastance of the LA (ELA) and LV (ELV) and the aortic (ao) and mitral valves (mi) by diodes.The systemic loop is comprised of a systemic arterial compliance represented by a capacitor (CV) and total peripheral resistance by a resistor (RV).
Mentions: For this study, a lumped parameter model with a variable elastance LV and 2 element (R and C) Windkessel afterload was chosen to model the LV in LVSD-HF [40]. It was chosen due to its elegance in representing the cardiovascular system, simplicity in manipulation, low computational demands and experience within the research group. This was downloaded from the CellML (http://www.cellml.org/) model repository, which is a free to access store of computer based mathematical models, and run using OpenCell, an open source platform for working with CellML models, see figure 4[41]. In this model the left atrium (ELA) and left ventricle (ELV) are represented by variable capacitors to model the pumping action of the left side of the heart, the mitral (mi) and aortic (ao) valves are represented by diodes to model unidirectional flow, the total peripheral resistance by a resistor, systemic vascular compliance by a capacitor and blood vessels by wire allowing for flow of electrons, representing the flow of blood.

Bottom Line: The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification.The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF.

View Article: PubMed Central - PubMed

Affiliation: Medical Physics Group, Department of Cardiovascular Science, University of Sheffield, Sheffield, S10 2TN, United Kingdom; Department of Cardiology, Northern General Hospital, Sheffield Teaching Hospitals, Sheffield, S5 7AU, United Kingdom.

ABSTRACT

Introduction: The American Heart Association (AHA)/American College of Cardiology (ACC) guidelines for the classification of heart failure (HF) are descriptive but lack precise and objective measures which would assist in categorising such patients. Our aim was two fold, firstly to demonstrate quantitatively the progression of HF through each stage using a meta-analysis of existing left ventricular (LV) pressure-volume (PV) loop data and secondly use the LV PV loop data to create stage specific HF models.

Methods and results: A literature search yielded 31 papers with PV data, representing over 200 patients in different stages of HF. The raw pressure and volume data were extracted from the papers using a digitising software package and the means were calculated. The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased. A 2-element lumped parameter model was employed to model the mean loops and the error was calculated between the loops, demonstrating close fit between the loops. The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).

Conclusions: For the first time, the authors have created a visual and quantitative representation of the AHA/ACC stages of LVSD-HF, from normal to end-stage. The study demonstrates that robust, load-independent and reproducible parameters, such as elastance, can be used to categorise and model HF, complementing the existing classification. The modelled PV loops establish previously unknown physiological parameters for each AHA/ACC stage of LVSD-HF, such as LV elastance and highlight that it this parameter alone, in lumped parameter models, that determines the severity of HF. Such information will enable cardiovascular modellers with an interest in HF, to create more accurate models of the heart as it fails.

Show MeSH
Related in: MedlinePlus