Significance of End-Diastolic Forward Flow in Patients With Repaired Tetralogy of Fallot ― Its Interaction With the Left Ventricular Property and End Organ Damage

Abstract

Background: Although right ventricular (RV) enlargement may affect RV diastolic dysfunction assessed by end-diastolic forward flow (EDFF) in patients with repaired tetralogy of Fallot (TOF), EDFF may also be modified by left ventricular (LV) hemodynamics. We hypothesized that EDFF is affected by LV hemodynamics, not limited to RV diastolic stiffening. Methods and Results: Among 145 consecutive patients with repaired TOF who underwent catheterization, hemodynamic properties in 47 with consistent EDFF and 75 without EDFF were analyzed. Compared with patients without EDFF, those with EDFF had a large RV volume with a high regurgitant fraction. Although cardiac index and central venous pressure (CVP) were similar, contrast injection augmented CVP and LV end-diastolic pressure (EDP) in patients with vs. those without EDFF, suggesting compromised diastolic reserve. In patients with EDFF, the velocity–time integral (VTI) of EDFF was positively correlated with LVEDP and systemic vascular resistance, in addition to RV EDP. EDFF-VTI was correlated with hepatic venous wedge pressure and markers of hepatic dysfunction. Subanalysis of the older (≥6 years) half of the study cohort revealed that EDFF was associated with bi-atrial enlargement independent of RV volume, highlighting the pronounced role of EDFF on the diastolic property in the aged cohort. Conclusions: EDFF-VTI in patients with repaired TOF reflects RV diastolic dysfunction, affected by the left heart system. EDFF-VTI indicates blood stagnation, which may be attributed to end-organ damage.