Our NIH-funded San Francisco POstmortem Systematic InvesTigation of Sudden Cardiac Death (POST SCD) Study, a first of its kind partnership between cardiac electrophysiology specialists and the County Medical Examiner to perform comprehensive autopsies and antemortem medical history review for every incident out-of-hospital sudden death within the County of San Francisco. We use this information to adjudicate underlying causes for all SCDs. These rigorous investigations of nearly every incident SCD in an entire metropolitan area represent the most comprehensive study of its kind on the epidemiology and underlying causes of SCD.