Effect of Varying Pericardial Boundary Conditions on Whole Heart Function: A Computational Study.

Pericardiectomy is recommended therapy for pericarditis, an inflammation of the pericardial layers that surround the heart and play a central role in maintaining cardiac performance. In some cases, the pericardium can be repaired or patched. However, the impact of changes in the pericardium on cardiac function is not clear. The objective of this study is to analyze the effect of the pericardium on whole-heart function by varying normal Robin boundary conditions (BCs) applied on the ventricular epicardium. A piece-wise linear penalty function was defined using two parameters that were varied to describe the regional scaling of normal spring stiffness from apex to base. Gaussian process emulators were used to perform a global sensitivity analysis on how the varying pericardial BCs affect cardiac biomechanics in four-chamber heart models. Our results have shown that pressure- and volume-derived biomarkers change by less than 25% due to variations in the pericardium, with more variation in the right ventricle compared to the left ventricle. On the other hand, measurements for systolic motion exhibited a range of variability greater than 100% of the baseline mean. We predict that the pericardium has limited impact on measures of global function but impacts measures of local cardiac biomechanics.