The progressive loss of cardiac myocytes by apoptotic cell death has been discussed as an important pathogenic component in the failing myocardium as well in the aging heart. The degree to which apoptosis contributes to myocyte loss in these conditions, however, is a controversial issue. This review focuses on the regulation of apoptosis, evidence implicating apoptosis as a mechanism for the progression and development of heart failure, the role of apoptotic death in senescent cardiac dysfunction, as well as on the problems of detection of apoptosis.