2. 3: Echocardiography:
Transthoracic echocardiographic study was performed for the neonates using IE 33 platform scanner (Philips Medical ultrasound systems, Washington, USA). Matrix-array transducer (S12) and (S8) were used for the 2D, M Mode and Doppler study. The studies were performed without sedation with babies asleep or suckling on bottle of milk.
Studies included recording of apical four chamber, three chamber and two chamber 2D views for quantification of global longitudinal strain and calculating ejection fraction. M-mode was used in parasternal short axis views for calculating fractional shortening. Images were stored in digital format for off-line analysis. The echocardiograms were downloaded to Xcelera R3.3 Cardiology PACS system (Philips Medical ultrasound systems, Washington, USA) and were analyzed and reported offline.