2.3. Echocardiographic assessment:
Standard techniques to obtain M-mode, two-dimensional and Doppler (color, pulsed, continuous and TDI) echocardiograms were performed by the same experienced pediatric cardiologist (RG.M) as recommended in the guidelines for the pediatric echocardiogram[27]. Images were obtained using Phillips IE33 ultrasound scanner with an 8 or 12 MHz sectorial transducer. Each examination was recorded, and all of the studies were reviewed off-line by 2 observers (RG:M & PR.A), who were blinded to the patient’s clinical profile. All echocardiographic measurements represent the average of 3 beats. Control and case echocardiographic data were deidentified before data analysis.