RT Journal Article SR Electronic T1 Contrast echocardiography during pericardiocentesis JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 329 OP 329 DO 10.1136/hrt.81.3.329 VO 81 IS 3 A1 T R Betts A1 J R Radvan YR 1999 UL http://heart.bmj.com/content/81/3/329.abstract AB