RT Journal Article SR Electronic T1 Emergency balloon mitral valvotomy for severe mitral stenosis during pregnancy JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 934 OP 934 DO 10.1136/hrt.2003.032144 VO 90 IS 8 A1 Shirodaria, C C A1 Mitchell, A R J A1 Banning, A P YR 2004 UL http://heart.bmj.com/content/90/8/934.abstract AB