Flow Energy Loss as a Predictive Parameter for Right Ventricular Deterioration Caused by Pulmonary Regurgitation After Tetralogy of Fallot Repair

Abstract

The optimal timing for pulmonary valve replacement after Tetralogy of Fallot (TOF) repair remains controversial. In this study, we estimated the feasibility of using flow energy loss (FEL) to predict right ventricular (RV) deterioration due to pulmonary regurgitation after TOF repair. We examined RV outflow tract (RVOT) flow in nine patients who underwent TOF or double-outlet right ventricle repair in the intervention group (Group I) and compared them with three healthy children in the control group (Group C). We evaluated flow across the RVOT and pulmonary valve by vector flow mapping (VFM) on echocardiography and by phase contrast-magnetic resonance imaging (PC-MRI). Next, we calculated FEL and analyzed the relationship between FEL and clinical parameters of RV function. The mean FEL was significantly greater in Group I than in Group C (p = 0.002). Flow pattern and FEL were comparable by VFM and PC-MRI at the same phase 14.6 years after TOF repair. There was a significant positive correlation for the cardiothoracic ratio with both the mean FEL [correlation coefficient (r) = 0.78; p = 0.012] and the diastolic peak FEL (r = 0.75; p = 0.021) in Group I. There was also a significant positive correlation between the serial change in QRS duration with both the mean FEL (r = 0.82; p = 0.014) and the diastolic FEL (r = 0.70; p = 0.052) in Group I. FEL by VFM is an effective tool for evaluating ventricular deterioration caused by RV workload.

Successful catheter ablation of atrial fibrillation improves but not reverses the abnormalities of left atrial mechanics and energy loss

“…Secondly, the software is used to applying in intraventricular flow velocity calculation, not atrial. EL reflects the total differences of neighboring velocity vectors; In the light of the principal of VFM (Figure ), the velocity vector component within LA is available and convincible, as the low velocity in LA ensures the quality of 2D color Doppler without the need for very high frame rates; it is reasonable, therefore, in our opinion, that the equation can be extrapolated to other chambers, like, as reported, the atrium or right ventricle …”

Energetic performance index improvement after Glenn and Damus-Kaye-Stansel procedure using vector flow mapping analysis: a case report

“…Echocardiography VFM enables us to evaluate the cardiac workload. Evaluation of pulmonary valve stenosis and association between right ventricular function deterioration and EL using VFM technology have been reported [3,9]. One of the wellknown concept of EL is the "energy loss concept," which is used to evaluate aortic stenosis [10], and the energy loss index is one of the predictors of prognosis in asymptomatic aortic stenosis [11].…”

Reconstruction of right ventricular outflow tract stenosis and right ventricular failure after Ross procedure – comprehensive assessment of adult congenital heart disease with four-dimensional imaging: a case report

“…FEL is known as a parameter of cardiac workload to predict ventricular deterioration in various heart diseases [6,7], including heart valve disease, cardiomyopathy, and congenital heart disease. Regarding the right ventricular deterioration, Shibata et al reported that FEL through the pulmonary valve after tetralogy of Fallot (TOF) repair was correlated with QRS duration prolongation in an electrocardiogram [8]. In our case, her FEL of the rightsided heart system calculated from four-dimensional flow MRI was very high due to the combination of It is reported that RV cannot obtain reverse remodeling of the normal range after pulmonary valve replacement (PVR), if re-operation is too late [9].…”

“…Regarding the right ventricular deterioration, Shibata et al . reported that FEL through the pulmonary valve after tetralogy of Fallot (TOF) repair was correlated with QRS duration prolongation in an electrocardiogram [ 8 ]. In our case, her FEL of the right-sided heart system calculated from four-dimensional flow MRI was very high due to the combination of moderate RVOT stenosis, moderate PR, and severe TR.…”