RT Journal Article SR Electronic T1 UPO: unidentified pericardial object JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 415 OP 415 DO 10.1136/heart.84.4.415 VO 84 IS 4 A1 JOLANDE BOLK A1 CONSTANT L A REICHERT YR 2000 UL http://heart.bmj.com/content/84/4/415.abstract AB