Effect of Pacing Site and Infarct Location on Regional Mechanics and Global Hemodynamics in a Model Based Study of Heart Failure

Clinical trials evaluating cardiac resynchronization therapy (CRT) have demonstrated that 30% of patients with heart failure and wide QRS do not respond to CRT (especially patients with myocardial infarcts). We have developed 3D numerical models of failing hearts, with and without chronic infarcts in different regions of the left ventricle. The hearts were coupled to a closed circulation, and the model included effects of the pericardium. The hearts were either paced at the right ventricular apex (RVA) or left ventricular free wall (LVFW). In normal and failing hearts, LV pump function was moderately better for LVFW pacing. In the normal heart model, heterogeneity of ejection strain was similar for RVA and LVFW pacing. However, in the failing heart model, LVFW pacing was associated with 44% less heterogeneity of ejection strain. This may be an important factor in the remodeling process associated with pacing.

[1]  G L Freeman,et al.  Pericardial Adaptations during Chronic Cardiac Dilation in Dogs , 1984, Circulation research.

[2]  L. Younes,et al.  Evidence of Structural Remodeling in the Dyssynchronous Failing Heart , 2005, Circulation research.

[3]  E. McVeigh,et al.  Electromechanics of paced left ventricle simulated by straightforward mathematical model: comparison with experiments. , 2005, American journal of physiology. Heart and circulatory physiology.

[4]  J. Tyberg,et al.  Left Ventricular Pacing Minimizes Diastolic Ventricular Interaction, Allowing Improved Preload-Dependent Systolic Performance , 2004, Circulation.

[5]  P. Trambaiolo,et al.  Biventricular pacing in heart failure: back to basics in the pathophysiology of left bundle branch block to reduce the number of nonresponders. , 2003, The American journal of cardiology.

[6]  Andrew D. McCulloch,et al.  Effect of Laminar Orthotropic Myofiber Architecture on Regional Stress and Strain in the Canine Left Ventricle , 2000 .

[7]  J. Guccione,et al.  MRI-based finite-element analysis of left ventricular aneurysm. , 2005, American journal of physiology. Heart and circulatory physiology.

[8]  H. Halperin,et al.  Systolic Improvement and Mechanical Resynchronization Does Not Require Electrical Synchrony in the Dilated Failing Heart With Left Bundle-Branch Block , 2002, Circulation.

[9]  Wolfgang G Rehwald,et al.  Infarct resorption, compensatory hypertrophy, and differing patterns of ventricular remodeling following myocardial infarctions of varying size. , 2004, Journal of the American College of Cardiology.

[10]  Roy C. P. Kerckhoffs,et al.  Coupling of a 3D Finite Element Model of Cardiac Ventricular Mechanics to Lumped Systems Models of the Systemic and Pulmonic Circulation , 2006, Annals of Biomedical Engineering.

[11]  E. McVeigh,et al.  Mapping propagation of mechanical activation in the paced heart with MRI tagging. , 1999, American journal of physiology. Heart and circulatory physiology.

[12]  Christophe Leclercq,et al.  Cardiac Dyssynchrony Analysis Using Circumferential Versus Longitudinal Strain: Implications for Assessing Cardiac Resynchronization , 2005, Circulation.

[13]  Bruce Tockman,et al.  Left ventricular resynchronization therapy in a canine model of left bundle branch block. , 2002, American journal of physiology. Heart and circulatory physiology.

[14]  Comparison of in situ and in vitro studies of pericardial pressure-volume relation in dogs. , 1986, The American journal of physiology.

[15]  Andrew D McCulloch,et al.  Electromechanical model of cardiac resynchronization in the dilated failing heart with left bundle branch block. , 2003, Journal of electrocardiology.

[16]  F. Prinzen,et al.  Quantification of interventricular asynchrony during LBBB and ventricular pacing. , 2002, American journal of physiology. Heart and circulatory physiology.