Flow Topology in the Right Ventricle after Tetralogy of Fallot Repair

Among all of the known congenital heart defects, Tetralogy of Fallot (TOF) is the most common cyanotic defect, accounting for 5{\%} of all detected defects. Approximately 1 in 2518 births will result with TOF, leading to about 1657 cases per year in the United States$^{\mathrm{\thinspace }}$alone. All of those affected will need surgical repair in order to have a relatively normal life and longer life span. Unfortunately, pulmonary regurgitation (PR) has been observed to appear two to three decades after the initial operation in 50{\%} of operated cases. PR results in abnormal flow patterns in the right ventricle, which are currently poorly understood. In this experimental study, several severities of pulmonary regurgitation were simulated on a newly developed right ventricle using a cardiovascular simulator. The interaction between the tricuspid valve inflow and the pulmonary regurgitation was investigated using Time-resolved particle image velocimetry (TR-PIV). PR resulted in a turbulent jet that disturbed the optimal filling of the RV. Energy losses and viscous shear stresses were observed to significantly increase with the severity of PR. This study can contribute towards a better understanding of the suboptimal performance in patients with repaired TOF.