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

Avesani M;Borrelli N; Krupickova S;Sabatino J; Donne GD; Ibrahim A; Piccinelli E; Josen M; Michielon G; Fraisse A; Iliceto S; Di Salvo G;

International journal of cardiology [Int J Cardiol] 2020 Jul 20. Date of Electronic Publication: 2020 Jul 20.

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 data with the gold standard CMR in a paediatric population of r-TOF with significant PR, to assess the reliability of standard and advanced echo parameters. In addition, to evaluate their correlation with peak oxygen consumption (VO 2 ).
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 > 21.9 cm 2 /m 2 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 CMR pulmonary regurgitant fraction (RF) ≥ 35%. None of the CMR parameters correlated with peak VO 2 . Among the Echo data only right atrial strain (RAS) correlated with peak VO 2.
CONCLUSION: In children, flow-reversal in pulmonary branches identifies hemodynamically significant RF with a good sensitivity but poor specificity. RV area by echocardiogram is a valid first-line parameter to screen RV dilation. RV longitudinal systolic dysfunction coexists with a still preserved EF. RAS correlates strongly with peak VO 2 and should be added in their follow up.