RT Journal Article SR Electronic T1 Prolonged QRS and QTc interval and mortality JF Heart JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 508 OP 509 VO 94 IS 4 A1 F Grigioni A1 G Piovaccari A1 G Boriani YR 2008 UL http://heart.bmj.com/content/94/4/508.3.abstract AB