Pre-symptomatic prediction of morbitidies in preterm infants with patent ductus arteriosus by targeted neonatal echocardiography and brain-type natriuretic peptide oleh Yasser Elsayed, Mary Seshia, Reeni Soni, Ilan Buffo, Ronald J. Baier, Patrick J. McNamara, Shyamala Dakshinamurti