A compressible myocardial tissue model predicted myofiber peak contractile stresses of 107.4 kPa, approximately half of the 182.8 kPa predicted by the standard incompressible model.
Does a compressible myocardial material model improve the accuracy of ventricular kinematics and active contraction estimates in an ovine model of myocardial infarction compared to an incompressible model?
Incorporating myocardial compressibility into cardiac computational models significantly improves the accuracy of simulated ventricular kinematics and provides more realistic estimates of active contraction levels in normal and infarcted hearts.
Absolute Event Rate: 107.4% vs 182.8%
Myocardial infarction (MI) rapidly impairs cardiac contractile function and instigates maladaptive remodeling leading to heart failure. Patient-specific models are a maturing technology for developing and determining therapeutic modalities for MI that require accurate descriptions of myocardial mechanics. While substantial tissue volume reductions of 15-20% during systole have been reported, myocardium is commonly modeled as incompressible. We developed a myocardial model to simulate experimentally-observed systolic volume reductions in an ovine model of MI. Sheep-specific simulations of the cardiac cycle were performed using both incompressible and compressible tissue material models, and with synchronous or measurement-guided contraction. The compressible tissue model with measurement-guided contraction gave best agreement with experimentally measured reductions in tissue volume at peak systole, ventricular kinematics, and wall thickness changes. The incompressible model predicted myofiber peak contractile stresses approximately double the compressible model (182.8 kPa, 107.4 kPa respectively). Compensatory changes in remaining normal myocardium with MI present required less increase of contractile stress in the compressible model than the incompressible model (32.1%, 53.5%, respectively). The compressible model therefore provided more accurate representation of ventricular kinematics and potentially more realistic computed active contraction levels in the simulated infarcted heart. Our findings suggest that myocardial compressibility should be incorporated into future cardiac models for improved accuracy.
Liu et al. (Tue,) conducted a other in Myocardial infarction (n=10). Compressible myocardial tissue material model vs. Incompressible myocardial tissue material model was evaluated on Myofiber peak contractile stress (kPa). A compressible myocardial tissue model predicted myofiber peak contractile stresses of 107.4 kPa, approximately half of the 182.8 kPa predicted by the standard incompressible model.