RT Journal Article SR Electronic T1 The ductus venosus JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 607a OP 607 DO 10.1136/hrt.78.6.607a VO 78 IS 6 A1 J S CARVALHO YR 1997 UL http://heart.bmj.com/content/78/6/607a.abstract AB