Abstract 19104: Hemodynamic Analysis of Pulmonary Artery for Congenital Right-Side Heart Disease in Adulthood by 4d-Flow MRI

Abstract

Introduction: Using 4D-flow MRI, we evaluated hemodynamics in the pulmonary artery of congenital right-side heart disease in adulthood. Hypothesis: We hypothesize that 4D flow MRI may be used to assess pulmonary artery flow hemodynamics in adults with congenital right heart disease. Methods: In 20 adults, we measured energy loss (EL) and helicity of the main pulmonary artery (MPA) by cardiovascular MRI. The maximum value (peak EL) in one heartbeat and the total value were obtained for EL. Helicity was defined as a vector quantity, with clockwise rotation being positive and counterclockwise rotation being negative, and the total value was calculated. Results: The mean age was 27.9 years. The cases included 15 cases of postoperative tetralogy of Fallot without pulmonary arterial hypertension (TOF) and 5 cases of congenital heart diseases with pulmonary arterial hypertension (CHD-PAH). Peak EL, time to peak EL, and total helicity were higher in the CHD-PAH group than TOF group. Peak EL values were significantly higher during systole but were observed during diastole in 8 patients (40%). The combined mean value of helicity was positive, with clockwise predominance in 12 cases (60%). A strong correlation was found between peak EL and clockwise helicity (r=0.68) and counterclockwise helicity (r=-0.73). In addition, a correlation was observed between diastolic EL/BSA and diastolic clockwise helicity (r=0.51) and diastolic counterclockwise helicity (r=-0.52). A correlation was also observed with the pulmonary regurgitant fraction (r=0.49). Conclusions: In this study, helicity in the MPA was dominant clockwise in congenital right-side heart disease in adulthood. It was suggested that EL was involved in helicity throughout the entire cardiac cycle and that peak EL had a particularly large effect.