RT Journal Article SR Electronic T1 Ultrastructure of the myocardium of the atrial appendage. JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 796 OP 807 DO 10.1136/hrt.28.6.796 VO 28 IS 6 A1 R A Lannigan A1 S A Zaki YR 1966 UL http://heart.bmj.com/content/28/6/796.abstract AB