RT Journal Article SR Electronic T1 Clinical significance of patent foramen ovale: introduction JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 437 OP 437 DO 10.1136/hrt.2004.052670 VO 91 IS 4 A1 F A Flachskampf A1 W G Daniel YR 2005 UL http://heart.bmj.com/content/91/4/437.1.abstract AB