PRE-DETERMINE is a multicenter prospective observational study designed to identify risk factors, including biologic and electrocardiographic markers, for sudden cardiac arrest resulting from heart rhythm disturbances in a cohort of 5,956 patients with a history of coronary artery disease or myocardial infarction. The public health impact of identifying such markers may be substantial, leading to more efficient utilization of implantable cardioverter defibrillators and advances in understanding of mechanisms underlying sudden cardiac death.