*4.4. Echocardiography Measurements*

Examinations were performed using Philips HD15 ultrasound machine (Philips Ultrasound, Bothell, WA, USA) with sector array transducer (3–8 MHz) incorporating color flow, pulse wave, and continuous wave Doppler measurements with adaptive technology. Children were calm and in supine position during ultrasound examination. A complete two-dimensional echocardiography was performed by a single investigator experienced with pediatric echocardiography. The transducer beam was kept as close as possible to the Doppler beam at <20% degrees to calculate valve regurgitation. No angle correction of Doppler signal was applied. Children with abnormal findings were referred to pediatric cardiologist.
