Senescence and arrhythmogenesis

Aging is associated with an increased incidence of cardiac arrhythmias that contributes significantly to the increased morbidity and mortality of old age.1-3 The increased susceptibility to both ventricular and atrial arrhythmias in the senescent heart occurs despite the absence of apparent disease and is exaggerated in the presence of underlying comorbidities.4,5 Cardiac dysrhythmias not only adversely affect the quality of life but also contribute to deterioration in myocardial function, increasing the susceptibility to heart failure, stroke, and sudden death.5-7 With the rapid increase in the elderly population and the prevalence of cardiovascular diseases in the elderly, it is projected that the number of patients with cardiac arrhythmias and associated disability will more than double in 30 years, placing an enormous burden on health care resources.8-10 Although progress is being made in understanding the pathogenesis of age-related cardiac diseases and therapies are being developed for these diseases, advanced age by itself poses significant dilemmas in therapy due to the lack of a full understanding of the molecular basis for the aging-associated increase in the susceptibility of the heart to arrhythmogenesis and the paucity of outcome studies in the very elderly.6,11 This chapter summarizes the epidemiology, aging-associated changes in cardiac structure and function, basis for arrhythmogenesis, and evaluation and management of elderly patients with ventricular tachyarrhythmias causing sudden death.