Sudden death (SD) of children and adults ages 1 to 40 years has received increasing attention over the past decades. In this report, we provide an overview of this problem, consider several mass screening strategies to prevent these events, and critically appraise these strategies in light of the well known Wilson and Jungner criteria (Table 1).1 Finally, we present an alternative approach: optimal assessment of first-degree relatives of newly diagnosed patients with an inherited cardiac disease and young SD victims to identify those relatives at risk of sudden cardiac death (SCD). View this table: Table 1. Wilson and Jungner Criteria for Assessment of Screening ### Definitions SD or its synonyms are generally defined as natural, unexpected death within 1 hour of the onset of symptoms.2 Four temporal elements should be considered in the use of this definition, that is, prodromes, onset of the terminal event, cardiac arrest, and biological death. The 1-hour definition refers to the period between onset of the terminal event, that is, acute changes in cardiovascular status, and cardiac arrest. Nonspecific prodromal symptoms, for example, chest pain, palpitations, or dyspnea, can be present during the days or weeks before a cardiac arrest.3 The biological legal death can occur days or weeks after the cardiac arrest, as patients can survive with irreversible brain damage and life support. In addition, when death occurs unwitnessed within 24 hours of being seen alive and functioning normally, this is also termed SD.2 In this report, the 1-hour definition is applied unless otherwise indicated. Depending on the underlying cause, SD can be divided into SCD, defined as SD from a cardiac cause,2 and SD due to noncardiac causes, for example, intracranial hemorrhage, epilepsy, pulmonary embolism, or asthma.4,5⇓ This subdivision is clinically relevant because cardiac causes are inherited in a significant …