Normative values of echocardiographic functional parameters in stable VLBW neonates during first month of life

This is an observational study of echocardiographic functional parameters in very low birth weight neonates admitted to NICU at Sir Ganga Ram hospital, New Delhi. All stable neonates <1500 grams at birth, admitted to NICU within 24 hrs of life will be enrolled and echocardiographic assessment of left ventricular output, right ventricular output, superior vena cava flow, inferior vena cava dimensions, myocardial shortening fraction will be measured at Day 3, 7, 14, 21, 28 and at discharge. Presence of patent ductus arteriosus (PDA) and various parameters of hemodynamic significance of ductus (duct size, flow pattern, duct flow velocity, left atrium to aortic root ratio, turbulance in main pulmonary artery, reversal of flow in post ductal aorta will be noted. spontaneous closure rates of PDA and proportion of neonates requiring pharmacological and surgical intervention for closure of PDA will be noted. Duct closure will be consider neonate is on invasive ventilation with FiO2 >30% and on echocardiograhy :if PDA is low velocity (<1.5 meter/sec) with left atrium to aortic root ratio >1.8.