Original articleAdult cardiacEffect of Adjustable Passive Constraint on the Failing Left Ventricle: A Finite-Element Model Study
Section snippets
Finite-Element Model
A three-dimensional FE model of the globally dilated LV based on LV dimensions obtained in dogs that had undergone serial intracoronary microsphere injection was created [14, 15]. The model was adjusted to match experimentally observed end-diastolic LV volume [16] and midventricular wall thickness. The experimental results used to create the model were previously reported.
The geometry of this model consisted of an axially symmetric prolate spheroid with a focus of 2.25 cm and a
Results
Using our FE model we could describe detailed average wall stress distribution and the LV pump function associated with different levels of passive constraint on the failing canine LV.
Comment
The principal finding of this study is that both stress and cardiac output decrease in a linear fashion as the amount of passive constraint is increased. Although no amount of pump function reduction is desirable, a small decrease may be acceptable if it leads to reverse remodeling and improved systolic function. According to the numerical model, if the reduction in cardiac output is to be less than 10%, passive constraint should not exceed 2.3 mm Hg. At that level of constraint, mean
References (28)
- et al.
Impact of left ventricular cavity size on survival in advanced heart failure
Am J Cardiol
(1993) Experimental and clinical studies with the Paracor cardiac restraint device
Semin Thorac Cardiovasc Surg
(2005)- et al.
Finite element stress analysis of left ventricular mechanics in the beating dog heart
J Biomech
(1995) - et al.
Reversal of left ventricular remodeling by pericardial tamponade
J Card Fail
(2005) - et al.
Isolated myocyte contractile function is normal in postinfarct remodeled rat heart with systolic dysfunction
Circulation
(1997) - et al.
Wall stress and patterns of hypertrophy in the human left ventricle
J Clin Invest
(1975) - et al.
Variables predictive of survival in patients with coronary diseaseSelection by univariate and multivariate analyses from the clinical, electrocardiographic, exercise, arteriographic, and quantitative angiographic evaluations
Circulation
(1979) - et al.
Echocardiographic variables as prognostic indicators and therapeutic monitors in chronic congestive heart failureVeterans Affairs cooperative studies V-HeFT I and II. V-HeFT VA Cooperative Studies Group
Circulation
(1993) - et al.
Reverse remodeling from cardiomyoplasty in human heart failureExternal constraint versus active assist
Circulation
(1995) - et al.
Mitral valve surgery in heart failure: insights from the Acorn Clinical Trial
J Thorac Cardiovasc Surg
(2006)
Adjustable, physiological ventricular restraint improves left ventricular mechanics and reduces dilatation in an ovine model of chronic heart failure
Circulation
Cardiac support device modifies left ventricular geometry and myocardial structure after myocardial infarction
Circulation
Passive ventricular constraint prevents transmural shear strain progression in left ventricle remodeling
Circulation
Ventricular constraint using the acorn cardiac support device reduces myocardial akinetic area in an ovine model of acute infarction
Circulation
Cited by (22)
Residual stress impairs pump function after surgical ventricular remodeling: A finite element analysis
2015, Annals of Thoracic SurgeryAlgisyl-LVR™ with coronary artery bypass grafting reduces left ventricular wall stress and improves function in the failing human heart
2013, International Journal of CardiologyBiventricular finite element modeling of the acorn CorCap cardiac support device on a failing heart
2013, Annals of Thoracic SurgeryCitation Excerpt :The fiber orientation of the Acorn case was taken to be approximately 45 degrees and –45 degrees, relative to the circumferential direction, and the rotated case was taken to be approximately 60 degrees and 0 degrees. Both sets of angles are based on previous measurements of the CSD [13]. We recently derived a material property law sufficient to describe the Acorn CSD fabric and measured material constants in silicone embedded fabric samples with a biaxial stretcher [14].
Optimized local infarct restraint improves left ventricular function and limits remodeling
2013, Annals of Thoracic SurgeryPatient-specific finite element-based analysis of ventricular myofiber stress after coapsys: Importance of residual stress
2012, Annals of Thoracic SurgeryCitation Excerpt :Although our previous FE simulation of surgical remodeling failed to show an effect of residual stress [26], the results of the current study clearly show a residual stress effect. Similar to our previous work [13, 14], the POSTOP FE model assumes that the ventricular wall was stress-free at the time of early diastolic filling. To specify residual stress in the POSTOP model requires a priori knowledge of the residual stress, which can be measured through destructive ex vivo experiments only and is thus impossible with the current in vivo study.
Growth and remodeling of the left ventricle: A case study of myocardial infarction and surgical ventricular restoration
2012, Mechanics Research CommunicationsCitation Excerpt :Since it is virtually impossible to measure regional stresses in the myocardial wall in vivo, these mathematical modeling seems to be a reasonable alternative. To date, most mathematical models focus on characterizing the acute, short-term impact of surgical procedures (Guccione et al., 2010; Jhun et al., 2010). Only recently, novel mathematical models have been proposed to study the chronic, long-term effects of clinical interventions (Baek and Humphrey, 2010; Kroon et al., 2009; Menzel, 2005).