Whole-Heart Assessment of Turbulent Kinetic Energy in the Repaired Tetralogy of Fallot

Approximately 10% of congenital heart diseases (CHDs) include Tetralogy of Fallot (TOF). Fortunately, due to advanced surgical techniques, most patients survive until adulthood. However, these patients require frequent monitoring for postoperative complications leading to heart hemodynamic alterations. Turbulent kinetic energy (TKE), as derived from 4D-flow magnetic resonance imaging (4D-flow MRI), has been used to characterize abnormal heart hemodynamics in CHD. Hence, this study aimed to assess the difference in TKE between patients with repaired TOF (rTOF) and healthy volunteers. A total of 35 subjects, 17 rTOF patients and 18 controls, underwent standard-of-care cardiac MRI and research 4D-flow MRI using a clinical 3T scanner. Heart chambers and great vessels were segmented using 3D angiograms derived from 4D-flow MRI. The TKE was quantified within segmented volumes. TKE was compared to standard cardiac MRI metrics. Controls demonstrated higher TKE in the left atria and left ventricle. However, patients demonstrated higher TKE in the right atria, right ventricle (p < 0.05), and pulmonary artery. Lastly, no correlation was observed between TKE and standard clinical measurements. TKE can be a key indicator of the abnormal hemodynamics present in patients with rTOF and can assist future interventions and help monitor long-term outcomes.