Echocardiography and cardiac magnetic resonance in children with repaired tetralogy of Fallot: New insights in cardiac mechanics and exercise capacity

Background: Pulmonary regurgitation (PR) and right ventricular (RV) dilatation and disfunction are common in patients with repaired Tetralogy of Fallot (r-TOF).Aims: To compare Echo datawith the gold standard CMR in a paediatric population of r-TOFwith significant PR, to assess the reliability of standard and advanced echo parameters. In addition, to evaluate their correlation with peak oxygen consumption (VO2).Methods and results: All patients underwent standard echo-Doppler study, speckle tracking analysis, and CMR to assess PR and RV size and function. Thirty-six patients underwent also cardiopulmonary exercise test. Fourty-six patients (aged 13.7 +/- 3.0) were included. Echo derived RV areas correlated with CMR RV volumes (p < .0001, r = 0.72). RV end-diastolic area N 21.9 cm2/m2 had a good sensitivity (83.3%) and specificity (73.5%) to identify a RV end-diastolic volume >= 150 ml/m(2). RVEF was preserved in all patients, while TAPSE was reduced in 78.2% and RVGLS in 60.8%. Flow-reversal in pulmonary branches showed a sensitivity of 95.8% and a specificity of 59.1% to identify CMRpulmonary regurgitant fraction (RF) = 35%. None of the CMRparameters correlated with peak VO2. Among the Echo data only right atrial strain (RAS) correlated with peak VO2.Conclusion: In children, flow-reversal in pulmonary branches identifies hemodynamically significant RF with a good sensitivity but poor specificity. RV area by echocardiogramis a valid first-line parameter to screen RV dilation. RV longitudinal systolic dysfunction coexistswith a still preserved EF. RAS correlates stronglywith peak VO2 and should be added in their follow up. (C) 2020 Elsevier B.V. All rights reserved.