RT Journal Article SR Electronic T1 Quadricuspid aortic valve JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 289 OP 289 DO 10.1136/hrt.2004.039289 VO 91 IS 3 A1 S M Divakaramenon A1 K Venugopal YR 2005 UL http://heart.bmj.com/content/91/3/289.abstract AB