RT Journal Article SR Electronic JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 373 OP 374 DO 10.1136/heart.85.4.373 VO 85 IS 4 A1 ROGER HALL A1 IQBAL MALIK YR 2001 UL http://heart.bmj.com/content/85/4/373.abstract AB