Senescence and arrhythmogenesis

Cardiac arrhythmias are a major cause of morbidity and mortality, particularly in the elderly. With the rapidly changing population demographics, and increasing prevalence of cardiovascular disease, healthcare resource utilization for arrhythmia care is projected to rise exponentially. Aging is associated with electrophysiological alterations due to cardiac structural and functional remodeling, which combined with a blunted response to neurohumoral activation and hemodynamic responsiveness, results in increased propensity to brady and tachy-arrhythmias. These not only affect the quality of life but also contribute to the deterioration in myocardial function leading to heart failure, stroke and death. Despite progress in the management of cardiovascular disease, arrhythmias in the elderly, continue to be a significant predicament. This is mainly due to limited understanding of the mechanisms and therapeutics directed against the underlying substrate that increases susceptibility of the heart to arrhythmogenesis and paucity of outcome studies in the older-elderly that limits specific practice guidelines in octo- and nona-genarians. Hence, further investigation is warranted to fully define the efficacy of anti-arrhythmic therapeutic modalities in the elderly that have proven to be effective in younger patients. This chapter summarizes the epidemiology, aging-associated cardiac structural and functional changes, basis for arrhythmogenesis, evaluation and management of elderly patients with ventricular tachyarrhythmias that increase predisposition to sudden death.