RT Journal Article SR Electronic T1 Managing heparin anticoagulation in patients with prosthetic cardiac valves: balancing the risk JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 1643 OP 1645 DO 10.1136/hrt.2009.171553 VO 95 IS 20 A1 Abdul Shlebak A1 Iqbal Malik YR 2009 UL http://heart.bmj.com/content/95/20/1643.abstract AB