Dynamic mode decomposition of Fontan hemodynamics in an idealized total cavopulmonary connection

Univentricular heart disease is the leading cause of death from any birth defect in the first year of life. Typically, patients have to undergo three open heart surgical procedures within the first few years of their lives to eventually directly connect the superior and inferior vena cavae to the left and right pulmonary arteries forming the total cavopulmonary connection (TCPC). The end result is a weak circulation where the single working ventricle pumps oxygenated blood to the body and de-oxygenated blood flows passively through the TCPC into the lungs. The fluid dynamics of the TCPC junction involve confined impinging jets resulting in a highly unstable flow, significant mechanical energy dissipation and undesirable pressure loss. Understanding and predicting such flows is important for improving the surgical procedure and for the design of mechanical cavopulmonary assist devices. In this study, dynamic mode decomposition (DMD) is used to analyze previously obtained stereoscopic particle imaging velocimetry (SPIV) data and large eddy simulation (LES) results for an idealized TCPC. Analysis of the DMD modes from the SPIV and LES serves to both highlight the unsteady vortical dynamics and the qualitative agreement between measurements and simulations.