RT Journal Article SR Electronic T1 Pneumopyopericardium, complicating penetrating gastric ulcer JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 285 OP 285 DO 10.1136/heart.85.3.285 VO 85 IS 3 A1 KNUDSEN, ANNE SEJR A1 JENSEN, SVEND EGGERT A1 EGEBLAD, HENRIK YR 2001 UL http://heart.bmj.com/content/85/3/285.abstract AB