Figure 1: Cardioverter defibrillator implant rates in survivors of out-of-hospital cardiac arrest in the United States and Canada. Data points centre on fiscal years, which end on March 31. Vertical lines indicate the publication of major secondary-prevention trials and guidelines, as follows. AVID = Antiarrhythmics Versus Implantable Defibrillators trial,7 published November 1997: N Engl J Med 1997;337:1576. ACC–AHA = American College of Cardiology–American Heart Association guidelines,11 April 1998: J Am Coll Cardiol 1998;31:1175. CIDS = Canadian Implantable Defibrillator Study,8 March 2000: Circulation 2000;101:1297. CASH = Cardiac Arrest Hamburg Study,9 August 2000: Circulation 2000;102:748.