Assessment of Left Ventricular Volume and Function Using Real-Time 3D Echocardiography versus Angiocardiography in Children with Tetralogy of Fallot

Background: Evaluation of left ventricular (LV) size and function is one of the important reasons for performing echocardiography. Real time three dimensional echocardiography (RT3DE) is now available for a precise non-invasive ventricular volumetry. Aim of work was to validate RT3DE as a non-invasive cardiac imaging method for measurement of LV volumes using cardiac angiography as the reference technique. Methods: Prospective study on 40 consecutive patients with tetralogy of Fallot (TOF) referred for cardiac catheterization for preoperative assessment. Biplane cineangiography, conventional 2 dimensional echocardiography (2DE) and RT3DE were performed for the patients. A control group of 18 age and sex matched children was included and 2DE and RT3DE were performed for them. Results: The mean LV end diastolic volume (LVEDV) and LVEDV index (LVEDVI) measured by RT3DE of patients were lower than controls (p value = 0.004, 0.01, respectively). There was strong correlation between the mean value of the LVEDV and the LVEDVI measured by RT3DE and angiography (r = 0.97, p < 0.001). The mean value of LV ejection fraction measured by RT3DE was lower than that assessed by 2DE ($50{\pm}6.2%$, $65{\pm}4.6%$, respectively, p value < 0.001) in the studied TOF cases. There was good intra- and inter-observer reliability for all measurements. Conclusion: RT3DE is a noninvasive and feasible tool for measurement of LV volumes that strongly correlates with LV volumetry done by angiography in very young infants and children, and further studies needed.