RT Journal Article SR Electronic T1 Effect of varying pulse interval in atrial fibrillation on left ventricular function in man. JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 388 OP 393 DO 10.1136/hrt.33.3.388 VO 33 IS 3 A1 D G Gibson A1 G Broder A1 E Sowton YR 1971 UL http://heart.bmj.com/content/33/3/388.abstract AB