Optimization of left ventricular ejection fraction measurement by two-dimensional echocardiography in patients with repaired tetralogy of Fallot: comparison of geometric methods with cardiovascular magnetic resonance

In patients with repaired tetralogy of Fallot (rTOF), left ventricular ejection fraction (LVEF) predicts adverse clinical outcomes. Cardiovascular magnetic resonance (CMR) is the gold standard for LVEF measurement, but two-dimensional echocardiography (2DE) is commonly used for serial evaluatio no f LVEF. The optimal 2DE method for LVEF measurement and limiting factors in this population are not known. Methods This single-center retrospective study included all patients with rTOF with CMR performed 2007-2010 without general anesthesia and 2DE within 3 months of CMR, with adequate images for analysis by all 2DE methods. Two investigators blinded to CMR results measured LVEF from 2DE studies by biplane Simpson’s (BiS) method (using apical 4-chamber and apical or parasternal 3-chamber images), 5/6 area*length (AL), and visual estimate. Two investigators blinded to 2DE results measured LVEF from CMR by Simpson’s method, as well as by AL, to test validity of geometric assumptions. An investigator re-evaluated each modality at least one month later. Results In 20 patients (28.5±14.7 years old, 40% female), visual estimation by 2DE best approximated LVEF by CMR