Right and left ventricular filling in adult patients with repaired tetralogy of fallot: a 4D flow MRI study.

In repaired Tetralogy of Fallot (TOF), RV replacement fibrosis is a predictor of hard events, but diastolic dysfunction, which should be related to ventricular fibrosis, is not part of the management process. 4D flow MRI may provide new insights about ventricular filling in repaired TOF. This study evaluates the relationship between RV and LV diastolic function and indicators of hemodynamic, exercise function and late gadolinium enhancement (LGE) in adults with repaired TOF. 41 TOF patients (22 male, mean age 38 ± 11 y) were retrospectively studied and compared with 21 controls. Early peak filling rate (PFR), atrial peak filling rate (PAFR) and filling volume (FV) were extracted from 4D flow for right (RV) and left (LV) ventricles. For the RV both tricuspid inflow and the whole RV filling (summing tricuspid inflow, and pulmonary regurgitation) were considered. Mitral and RV PFR/PAFR were significantly higher in TOF than in controls (2.59 [1.62-3.86] vs. 1.52 [1.20-2.07]; p < 0,001 and 2.06 [1.38-3.53] vs. 1.2 [0.88-1.53]; p < 0.001). Mitral PFR/PAFR ratio was decreased in patient with VO2 peak < 23 mL.kg.min (3.28[2.40-3.88] vs. 1.75 [1.18-3.07,p = 0.027). RV PFR/PAFR was decreased in patient with severe junctional LGE (PFR/PAFR of 2.61 [2.11-3.75 vs. 2.19 [1.62-3.7] vs. 1.33 [1.02-1.67], in none to minimal, mild to moderate and severe LGE groups respectively, p = 0.011). LV diastolic function was impaired in case of decreased exercise performance and RV impaired relaxation was more prevalent in case of junctional LGE.