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LEARNING OBJECTIVES

Learning Objectives

  • Understand the etiologies of bradyarrhythmias, indications for pacemaker placement, and selection of the pacemaker mode.

  • Discuss the goals of rate and rhythm control and approach to anticoagulation in older patients with atrial fibrillation (AF).

  • Understand the indications for cardioverter-defibrillator and cardiac resynchronization therapy.

Key Clinical Points

  1. Age-related changes throughout the heart and conduction system predispose older individuals to bradyarrhythmias, conduction disturbances, and supraventricular and ventricular tachyarrhythmias, all of which increase in incidence and prevalence with advancing age.

  2. The indications for invasive electrophysiologic testing are generally similar in younger and older patients.

  3. The indications for permanent pacing for treatment of bradyarrhythmia are similar in older and younger patients. More than 80% of permanent pacemakers are placed in patients 65 years or older, with sinoatrial dysfunction being the leading indication for pacemaker implantation in this age group.

  4. Compared with single-chamber ventricular pacing, dual-chamber pacing reduces the risk of AF but does not affect mortality or the risk of stroke.

  5. Age greater than 75 is a well-recognized risk factor for thromboembolism in patients with AF.

  6. In asymptomatic or minimally symptomatic patients with AF, a strategy of rate control and anticoagulation is associated with equivalent or better outcomes than a strategy of rhythm control.

  7. In patients with symptomatic AF refractory to pharmacologic treatment, various catheter-based ablation procedures, as well as the surgical maze procedure, provide effective control of rate and/or arrhythmia in a high proportion of patients.

  8. The indications for implantable cardioverter-defibrillator and cardiac resynchronization therapy are similar in older and younger patients, as are the benefits in terms of reducing mortality and improving symptoms. However, few data are available on the use of these devices in patients older than 80 years.

In older patients without apparent cardiovascular disease, the number of cardiac myocytes declines, while residual myocytes enlarge. Concurrently, there is an increase in elastic and collagenous tissue in all parts of the interstitial matrix and conduction system with advancing age. Calcification of the cardiac skeleton, which includes the aortic and mitral annuli, the central fibrous body, and the summit of the atrioventricular (AV) septum, also increases with age. Due to its proximity to these structures, the conduction system is likewise affected by aging. Prolongation of action potential duration and diminished autonomic response also develop in conjunction with the aging process. Taken together, these changes provide the substrate for the age-related increase in propensity for chronotropic and dromotropic incompetence and for the development of atrial and ventricular arrhythmias.

BRADYARRHYTHMIAS AND CARDIAC PACEMAKER THERAPY

Sinus Node Dysfunction

Pacemaker therapy is indicated in patients with symptomatic bradycardia (syncope, presyncope, dyspnea, and exercise intolerance) correlated to sinus node dysfunction (SND), manifest as pauses, persistent bradycardia, or chronotropic incompetence. It is acceptable to proceed with implantation of a single chamber pacemaker (atrial lead, AAI or AAIR mode). However, it must be taken into consideration that concomitant AV conduction disease ...

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