This study introduced a combined computational fluid dynamics (CFD) and echocardiography methodology to simulate blood flow in the single right ventricle (SRV) and normal ventricles to study the intraventricular flow. Derived from echocardiographic image loops, CFD-based three-dimensional (3D) flow models of normal subject's left ventricle (LV) and right ventricle (RV) and SRV with and without heart failure at three characteristic diastolic statuses were reconstructed. The CFD derived morphological and functional measurements in normal ventricles and the SRV were validated with echocardiography. The vortex in the normal ventricles and the SRV were studied. The morphological and functional measurements derived from CFD modeling and echocardiography were comparable, and both methods demonstrated the larger volume and higher spherical index in the SRV, in particular the SRV with heart failure. All the vortices in the SRV were smaller than those in the normal control subject's LV and RV, notably with heart failure. Unlike normal LV and RV, no vortex ring was observed in the SRV. Echocardiography-based CFD demonstrated the feasibility of quantifying ventricular morphology and function; in addition, CFD can detect the abnormal flow pattern (smaller or obliterated vortices) in the SRV when compared with normal ventricles.

Objective: Pulmonary hypertension related to congenital heart disease (PH-CHD) is a devastating disease caused by hemodynamic disorders. Previous hemodynamic research in PH-CHD mainly focused on wall shear stress (WSS). However, energy loss (EL) is a vital parameter in evaluation of hemodynamic status. We investigated if EL of the pulmonary artery (PA) is a potential biomechanical marker for comprehensive assessment of PH-CHD.Materials and Methods: Ten PH-CHD patients and 10 age-matched controls were enrolled. Subject-specific 3-D PA models were reconstructed based on computed tomography. Transient flow, WSS, and EL in the PA were calculated using non-invasive computational fluid dynamics. The relationship between body surface area (BSA)-normalized EL (E.) and PA morphology and PA flow were analyzed.Results: Morphologic analysis indicated that the BSA-normalized main PA (MPA) diameter (DMPAnorm), MPA/aorta diameter ratio (DMPA/DAO), and MPA/(left PA + right PA) [DMPA/D(LPA+RPA)] diameter ratio were significantly larger in PH-CHD patients. Hemodynamic results showed that the velocity of the PA branches was higher in PH-CHD patients, in whom PA flow rate usually increased. WSS in the MPA was lower and E. was higher in PH-CHD patients. E. was positively correlated with DMPAnorm, DMPA/DAO, and DMPA/D(LPA+RPA) ratios and the flow rate in the PA. E. was a sensitive index for the diagnosis of PH-CHD.Conclusion:E. is a potential biomechanical marker for PH-CHD assessment. This hemodynamic parameter may lead to new directions for revealing the potential pathophysiologic mechanism of PH-CHD.

The question of preserving the patent ductus arteriosus (PDA) during the modified Blalock–Taussig shunt (MBTS) procedure remains controversial. The goal of this study was to investigate the effects of the PDA on the flow features of the MBTS to help with preoperative surgery design and postoperative prediction. In this study, a patient with pulmonary atresia and PDA was included. A patient-specific three-dimensional model was reconstructed, and virtual surgeries of shunt insertion and ductus ligation were performed using computer-aided design. Computational fluid dynamics was utilized to analyze the hemodynamic parameters of varied models based on the patient-specific anatomy and physiological data. The preservation of the PDA competitively reduced the shunt flow but increased total pulmonary perfusion. The shunt flow and ductal flow collided, causing significant and complicated turbulence in the pulmonary artery where low wall shear stress, high oscillatory shear index, and high relative residence time were distributed. The highest energy loss was found when the PDA was preserved. The preservation of PDA is not recommended during MBTS procedures because it negatively influences hemodynamics. This may lead to pulmonary overperfusion, inadequate systemic perfusion, and a heavier cardiac burden, thus increasing the risk of heart failure. Also, it seems to bring no benefit in terms of reducing the risk for thrombosis.