Fetal heart computational modeling

Abstract

Among infants born with cardiac defects, congenital heart disease (CHD) is the leading congenital abnormality and it origins the majority of newborns death in developed countries. The structural malformations in the heart or great vessels it causes increase the postnatal cardiovascular risk and mortality. In particular, the high incidence of tetralogy of Fallot (ToF) in live births make essential to develop new procedures that enable the study and understanding of this cardiac disorder and the hemodynamic changes it induces. That way, fetal medicine has been constantly evolving in the past years, and computational modeling techniques are becoming more established in the clinical practice and are of growing importance. Nowadays, different 0D lumped parameters models have demonstrated to be useful to evaluate complex cardiac defects in order to aid health workers and find the best management for patients. In this project, a 0D lumped model simulating hemodynamic components and parameters of the fetal heart was developed to study the changes occurring in a ToF heart. Specifically, birth defects of ventricular septal defect (VSD) and pulmonary valve stenosis (PVS) were modeled, allowing the analysis of their effects in fetal circulation. Our results suggested that the designed 0D lumped model can reproduce the blood velocities and pressure waveforms of the fetal heart in healthy conditions after adjusting the values of some model parameters. Despite that, the parameters of the ductus arteriosus (DA) should be better fit since we could not completely reproduce its velocity waveform. Regarding the evaluation of hemodynamic changes of cardiac defects, results suggested that the 0D lumped model can simulate the features present in ToF, such as the right-to-left shunt, characteristic of blood flow in VSD, and the increase of the pressure gradient and peak velocity of the pulmonary artery, indicative of PVS. However, more literature and clinical data of cardiac defects should be used in order to verify these outcomes and ensure their reliability.