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A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles.

Choi YJ, Constantino J, Vedula V, Trayanova N, Mittal R - Front Bioeng Biotechnol (2015)

Bottom Line: The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver.The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart.We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA.

ABSTRACT
A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier-Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.

No MeSH data available.


Related in: MedlinePlus

P–V loop: comparison of volume-averaged left ventricular pressure from the Navier–Stokes equations (solid line) with the pressure obtained from the lumped parameter model (dotted line). (A) Normal heart with SR activation; (B) normal heart with LBBB activation; (C) failing heart with SR activation; (D) failing heart with LBBB activation. SR, sinus rhythm; LBBB, left bundle branch block.
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Figure 11: P–V loop: comparison of volume-averaged left ventricular pressure from the Navier–Stokes equations (solid line) with the pressure obtained from the lumped parameter model (dotted line). (A) Normal heart with SR activation; (B) normal heart with LBBB activation; (C) failing heart with SR activation; (D) failing heart with LBBB activation. SR, sinus rhythm; LBBB, left bundle branch block.

Mentions: The left ventricular pressure–volume (P–V) loops for all the four canine hearts are plotted in Figure 11. The volume-averaged P–V loops are also compared with the corresponding loops obtained from the lumped parameter model (Kerckhoffs et al., 2007). The two P–V loops agree quite well for normal hearts with both the SR as well as the LBBB activation. By contrast, for the failing hearts, the lumped parameter model significantly over-predicts the systolic LV pressure when compared to the volume-averaged NSH model (10.7 versus 9.0 kPa for the SR model and 12.5 versus 10.3 kPa for the LBBB activation model). The models with LBBB activation (both normal and failing) generate lower systolic ventricular pressure compared to the ones with SR activation.


A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles.

Choi YJ, Constantino J, Vedula V, Trayanova N, Mittal R - Front Bioeng Biotechnol (2015)

P–V loop: comparison of volume-averaged left ventricular pressure from the Navier–Stokes equations (solid line) with the pressure obtained from the lumped parameter model (dotted line). (A) Normal heart with SR activation; (B) normal heart with LBBB activation; (C) failing heart with SR activation; (D) failing heart with LBBB activation. SR, sinus rhythm; LBBB, left bundle branch block.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585083&req=5

Figure 11: P–V loop: comparison of volume-averaged left ventricular pressure from the Navier–Stokes equations (solid line) with the pressure obtained from the lumped parameter model (dotted line). (A) Normal heart with SR activation; (B) normal heart with LBBB activation; (C) failing heart with SR activation; (D) failing heart with LBBB activation. SR, sinus rhythm; LBBB, left bundle branch block.
Mentions: The left ventricular pressure–volume (P–V) loops for all the four canine hearts are plotted in Figure 11. The volume-averaged P–V loops are also compared with the corresponding loops obtained from the lumped parameter model (Kerckhoffs et al., 2007). The two P–V loops agree quite well for normal hearts with both the SR as well as the LBBB activation. By contrast, for the failing hearts, the lumped parameter model significantly over-predicts the systolic LV pressure when compared to the volume-averaged NSH model (10.7 versus 9.0 kPa for the SR model and 12.5 versus 10.3 kPa for the LBBB activation model). The models with LBBB activation (both normal and failing) generate lower systolic ventricular pressure compared to the ones with SR activation.

Bottom Line: The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver.The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart.We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA.

ABSTRACT
A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier-Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.

No MeSH data available.


Related in: MedlinePlus