**1. Introduction**

Sudden cardiac death (SCD) is a major cause of death in the USA and accounts for almost half of all cardiovascular deaths. The estimated annual incidence of SCD in the USA stands at 300,000 to 350,000. A significant fraction of the patients who die from SCD have underlying cardiovascular pathology, most commonly some form of cardiomyopathy but, often the disease remains unrecognized presenting with SCD as the first event. Ischemic heart disease is overwhelmingly the commonest cause of SCD but other forms of cardiomyopathy become more important cause of SCD in younger population. Although the patients with cardiomy‐ opathy account for a small fraction of population burden of SCD, a subset of these patients are at high risk and this rationalizes aggressive preventive strategy in them (figure 1). Lower prevalence of ischemic heart disease in younger population makes other forms of cardiomy‐ opathy more important in that population. Moreover, the relative contribution of SCD in the population has changed as the epidemiology, natural course and outcomes of lifestyle related cardiovascular diseases, particularly ischemic heart disease, have changed. In this chapter we will review sudden cardiac death in patients with cardiomyopathies focusing on epidemiology and risk stratification of SCD, and approaches for primary and secondary prevention strategies in them.
