We present a patient-specific computational fluid dynamics (CFD) framework to characterize right ventricle–pulmonary artery (RV–PA) coupling in pulmonary hypertension. Prior investigations have shown that prolonged vortex duration in the PA correlates with pulmonary hypertension, but they often neglect direct RV modelling. Our approach addresses this gap by jointly capturing RV and proximal PA wall motion, which is central to understanding how ventricular contraction influences flow structures and potential remodelling in the pulmonary circulation.
A 4D cardiac CT dataset (20 phases, 0.844 s per cycle, HR = 72 bpm) was acquired from a patient evaluated before transcatheter aortic valve implantation. We manually segmented the RV and proximal PA at end-systole and end-diastole, then registered the incomplete dynamic PA volumes to a contrast-enhanced thoracic CT to reconstruct the complete arterial geometry. Using MIRTK, we performed joint wall-motion tracking of the RV and PA, enforcing continuity across the pulmonary valve. This provided a conformal mesh at the RV–PA interface, enabling staged boundary conditions for diastolic inflow (tricuspid valve) and systolic outflow (pulmonary valve).
We applied three-element Windkessel models at both left and right PA outlets, initializing parameters from invasive hemodynamic data (mean PA pressure (mPAP) = 32 mmHg, Pulmonary Capillary Wedge Pressure (PCWP) = 22 mmHg, cardiac output = 6.1 L/min) and refining them Using a personalized Simulink circuit (MATLAB R2024a) to approximate patient-specific RV pressure–flow waveforms. Our simulations aim to characterize how incorporating full RV motion affects the formation and persistence of vortices near the PA bifurcation. These findings suggest that coupling the RV and PA within a single CFD model may be key to identifying early flow-based biomarkers of adverse remodelling. Ongoing work includes systematic validation against Doppler or phase-contrast MRI, with the longer-term goal of improving clinical detection and management of pulmonary hypertension.