Conventional Transthoracic Echocardiography:
A ultrasound system (iE33, Philips, The Netherlands, Eindhoven), equipped with a broadband S8-3(8-3 MHz) Sector Array transducer was used to obtain images. Postnatal first and second echo were performed when baby is asleep or at rest. 2D, M-mode, PW doppler and TDI measurements described above were applied in accordance with the guidelines of the American Society of Echocardiography [12,13]. Left ventricular mass (LVM) measurements were normalised to body surface area (BSA) as indexed LVM index (LVMi) as using the equation (0.8{1.04[([LVDD+IVSd+LVPWd]3-LVDD3)]}+0.6)/BSA.