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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 data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased.The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).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

Graph showing mean pressure volume loop for each American Heart Association (AHA)/American College of Cardiology (ACC) heart failure (HF) stage (shown as white triangles) and standard error (shown black lines).
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pone-0114153-g008: Graph showing mean pressure volume loop for each American Heart Association (AHA)/American College of Cardiology (ACC) heart failure (HF) stage (shown as white triangles) and standard error (shown black lines).

Mentions: For clarity, we have just shown the raw and mean loops from one stage, AHA/ACC D (figure 7). It is evident that even within AHA/ACC stages there is individual variation, both in terms of LV pressure and volume. Figure 8 demonstrates the standard error for each of the PV points derived from patients in this stage, reflecting this large spread. Table 4 demonstrates, that there is no statistically significance differences between stages O and A or B, but together they are significantly different from stages C and D in all variables, other than other than minimal elastance. There are no significant differences between stages C and D.


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)

Graph showing mean pressure volume loop for each American Heart Association (AHA)/American College of Cardiology (ACC) heart failure (HF) stage (shown as white triangles) and standard error (shown black lines).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0114153-g008: Graph showing mean pressure volume loop for each American Heart Association (AHA)/American College of Cardiology (ACC) heart failure (HF) stage (shown as white triangles) and standard error (shown black lines).
Mentions: For clarity, we have just shown the raw and mean loops from one stage, AHA/ACC D (figure 7). It is evident that even within AHA/ACC stages there is individual variation, both in terms of LV pressure and volume. Figure 8 demonstrates the standard error for each of the PV points derived from patients in this stage, reflecting this large spread. Table 4 demonstrates, that there is no statistically significance differences between stages O and A or B, but together they are significantly different from stages C and D in all variables, other than other than minimal elastance. There are no significant differences between stages C and D.

Bottom Line: The data demonstrated that, as HF progressed, stroke volume (SV), ejection fraction (EF%) decreased while LV volumes increased.The only parameter that was consistently and statistically different across all the stages was the elastance (Emax).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