Left ventricular extracellular volume is associated with loss of exercise tolerance in children after Tetralogy of Fallot repair, but not with ventricular dysfunction

Methods In 25 patients (age 13.6±2.5 years, 14 male) after surgical repair of Tetralogy of Fallot (ToF), T1 measurements were performed at a mid and basal ventricular level in short axis before and 15 minutes after the application of 0.1 mmol/kg gadobenate dimeglumine in the interventricular septum (IVS), left ventricular (LV) lateral wall, complete LV myocardium and diaphragmatic portion of the right ventricle (RV). The extracellular volume (ECV) was calculated from native and post-contrast T1 times of myocardium and blood and the hematocrit. Peak circumferential (LV), longitudinal (RV) and radial (RV) strain as well as the standard deviation of the time to peak strain of different segments (SDpeak) were measured using CMR feature tracking. The correlation of native T1 times and ECV with strain parameters was tested using Pearson’s coefficient. Native T1 times and ECV were correlated to exercise test results.