Mechanisms of arrhythmias and conduction disorders in older adults

Abstract

Aging is associated with an increased prevalence of cardiac arrhythmias, which contribute to higher morbidity and mortality in the elderly. The frequency of cardiac arrhythmias, particularly atrial fibrillation and ventricular tachyarrhythmia, is projected to increase as the population ages, greatly impacting health care resource utilization. Several clinical factors associated with the risk of arrhythmias have been identified in the population, yet the molecular bases for the increased predisposition to arrhythmogenesis in the elderly are not fully understood. This review highlights the epidemiology of cardiac dysrhythmias, changes in cardiac structure and function associated with aging, and the basis for arrhythmogenesis in the elderly.

Fig. 1

A: Prevalence of atrial fibrillation (AF) in older adults doubles with each decade. Prevalence increases 80–100-fold in the very elderly (0.1% at 40 years to ~8–10% in ≥ 80 years). (Adapted from Feinberg et al. Prevalence, age distribution, and gender of patients with atrial fibrillation analysis and implications. Arch Int Med 1995;155:469–73, with permission from American Medical Association.) Inset: Cumulative lifetime risk for the development of AF (~25%) in the adult population. (Adapted from Lloyd-Jones et al. Lifetime risk for development of atrial fibrillation: The Framingham Heart Study. Circulation 2004;110:1042–6, with permission from Wolters Kluwer Health.) B: Secular trends in prevalence of AF in Olmsted County, MN: 1960–1989. (Adapted from Tseng et al. The prevalence of atrial fibrillation in incident stroke cases and matched population controls in Rochester, Minnesota: changes over three decades. J Am Coll Cardiol 2003;42:93–100, with permission from Elsevier.)

Fig. 2

Age-related changes in human left atrial voltage loss determined by three-dimensional electroanatomic bipolar voltage mapping. Group A includes those ≥60 years of age; Group B 31–59 years; and Group C ≤30 years. Color annotation: Bipolar voltages from 0.5 mV (in red) to voltages 5 mV (in purple). CS = coronary sinus; DP = double potentials; FS = fractionated signals; PA = posteroanterior; SVC = superior vena cava. (Reproduced from Kistler et al. Electrophysiologic and electroanatomic changes in the human atrium associated with age. J Am Coll Cardiol 2004;44:109–16, with permission from Elsevier.)