RT Journal Article SR Electronic T1 THE EARLY SYSTOLIC SOUND IN DILATATION OF THE PULMONARY ARTERY JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 21 OP 33 DO 10.1136/hrt.16.1.21 VO 16 IS 1 A1 Aubrey Leatham A1 Louis Vogelpoel YR 1954 UL http://heart.bmj.com/content/16/1/21.abstract AB