Sudden cardiac death: exploring the limits of our knowledge.

Despite progress in epidemiology, clinical profiling, and interventions, sudden cardiac death remains a major clinical and public health problem. There remain important unresolved issues that are challenges for future progress. Among these are a better understanding of the magnitude of the problem and methods of profiling risk for individuals, the etiology and mechanisms of cardiac arrest in individuals with and without previously identified structural heart disease, clinical strategies for primary and secondary prevention of sudden cardiac death, and further development of community programs for improving cardiac arrest survival in the out-of-hospital environment. Each of these areas of endeavor and potential progress are reviewed and discussed.