RESUMO
Background: Echocardiographic quantification of left ventricular (LV) volume and ejection fraction (EF) is widely used in the pediatric population. However, there is no consensus on the most accurate method of quantifying ventricular volumes and systolic function. Purpose: The purpose of this study is to compare two commonly used echocardiographic methods for the evaluation of LV volume and quantification of EF, the five-sixth area-length (5/6 AL) and the modified biplane Simpson (BS), to cardiac magnetic resonance (CMR) imaging in children. Methods: CMR studies were paired with echocardiograms and retrospectively analyzed in children 18 years of age and younger. Studies performed more than 3 months between modalities, patients with congenital heart disease, and patients who had changes in medication regimen between corresponding CMR and echocardiograms were excluded. LV volumes and EF were calculated using the 5/6 AL and BS methods and compared to volumes and EF measured on corresponding CMR studies. Subgroup analyses were conducted based on LV function, pathology, and weight. Results: We retrospectively analyzed 53 CMR and corresponding echocardiogram studies (23 studies for myocarditis and 30 studies for cardiomyopathy) in 46 patients. LVEF derived by both echocardiographic methods showed a good correlation to CMR (5/6 AL r = 0.85 and BS r = 0.82). However, both echocardiographic methods overestimated LVEF and underestimated LV volumes when compared to CMR. Conclusion: Left ventricular volumes and EF, as measured by echocardiography, correlate well with CMR measurements. Echocardiography underestimates LV systolic and diastolic volumes and overestimates LVEF. While echocardiography is a good surrogate for estimating LVEF, CMR should be considered in patients for whom accurate measurements are needed for critical clinical decision-making.