Right ventricular Direct Flow possessed larger presystolic kinetic energy (0.4 ± 0.3 mJ) than other flow components (P<0.01) and a larger part of end-diastolic volume than LV Direct Flow (P<0.01).
Cross-Sectional (n=10)
How do the proportions and energetics of right ventricular blood flow components compare to the left ventricle in healthy subjects?
4D flow MRI reveals that normal RV diastolic flow patterns preserve kinetic energy, creating favorable conditions for systolic ejection, which differs from LV flow dynamics.
p-value: p=<0.01
Right ventricular (RV) function is a powerful prognostic indicator in many forms of heart disease, but its assessment remains challenging and inexact. RV dysfunction may alter the normal patterns of RV blood flow, but those patterns have been incompletely characterized. We hypothesized that, based on anatomic differences, the proportions and energetics of RV flow components would differ from those identified in the left ventricle (LV) and that the portion of the RV inflow passing directly to outflow (Direct Flow) would be prepared for effective systolic ejection as a result of preserved kinetic energy (KE) compared with other RV flow components. Three-dimensional, time-resolved phase-contrast velocity, and balanced steady-state free-precession morphological data were acquired in 10 healthy subjects using MRI. A previously validated method was used to separate the RV and LV end-diastolic volumes into four flow components and measure their volume and KE over the cardiac cycle. The RV Direct Flow: 1) followed a smoothly curving route that did not extend into the apical region of the ventricle; 2) had a larger volume and possessed a larger presystolic KE (0.4 ± 0.3 mJ) than the other flow components (P < 0.001 and P < 0.01, respectively); and 3) represented a larger part of the end-diastolic blood volume compared with the LV Direct Flow (P < 0.01). These findings suggest that diastolic flow patterns distinct to the normal RV create favorable conditions for ensuing systolic ejection of the Direct Flow component. These flow-specific aspects of RV diastolic-systolic coupling provide novel perspectives on RV physiology and may add to the understanding of RV pathophysiology.
Fredriksson et al. (Sat,) conducted a cross-sectional in Healthy (n=10). Right ventricular blood flow assessment via 4-D MRI vs. Left ventricular blood flow and other RV flow components was evaluated on Volume and kinetic energy of right ventricular flow components (p=<0.01). Right ventricular Direct Flow possessed larger presystolic kinetic energy (0.4 ± 0.3 mJ) than other flow components (P<0.01) and a larger part of end-diastolic volume than LV Direct Flow (P<0.01).