TY - JOUR T1 - The authors reply JF - British Heart Journal JO - Heart SP - 491 LP - 492 DO - 10.1136/hrt.62.6.491 VL - 62 IS - 6 AU - C J Burrell AU - D R Blake Y1 - 1989/12/01 UR - http://heart.bmj.com/content/62/6/491.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -