Nonpharmacologic Treatment of Atrial Fibrillation
Year: 2002
Type: book-chapter
Abstract: The prevalence of atrial fibrillation (AF) (1) has risen as the population of individuals over 60 years old has increased, fostering a growing need to develop better and more cost-effective means of controlling and preventing AF. Although pharmacological rate control, suppression of recurrent AF, and stroke prevention are the principal therapeutic strategies (2), these approaches have significant limitations. Pharmacological control of the ventricular rate is achievable in most patients with AF; however, many patients may have rapid rates during portions of the day, particularly during exertion or stress (3,4). If unrecognized and uncontrolled, these rapid ventricular rates may result in a tachycardia-induced cardiomyopathy over a period of months to years (5). Pharmacologic approaches to maintain sinus rhythm in patients with AF are even less effective, with arrhythmia recurrence rates of approx 50% at 6–12 mo of follow-up, regardless of the antiarrhythmic drug used(6–9). Pharmacologic maintenance of sinus rhythm may be considered a palliative rather than curative approach, with efficacy now determined as the median time to AF recurrence rather than the number of patients without recurrence, since the latter approaches zero in long-term follow-up (2). All drugs are associated with the risk of serious and troubling side effects. With the atrioventricular (AV)-nodalblocking agents and class I and III antiarrhythmic drugs, these side effects include
Table 1
Nonpharmacologic Approaches to AF
Rate control
Restoration/maintenance of sinus rhythm
AV-junction ablation
DC cardioversion (e.g., biphasic external, intracardiac)
AV-junction modification
Single- and dual-site atrial pacing
Implantable atrial defibrillator (IAD)
Surgical ablation
Focal and linear catheter ablation
fatigue, decreased exercise capacity, depression, symptomatic bradycardia, worsening heart failure, and, more rarely, organ toxicity. Amiodarone may have greater efficacy than other class I and III antiarrhythmic drugs (9), but is associated with higher rates of discontinuation—about 35% after several years—because of organ toxicity (10,11). Furthermore, all antiarrhythmic drugs have an associated risk of proarrhythmia, which may be life-threatening. Rates of proarrhythmia vary from 1-4%, depending upon the specific class I or III antiarrhythmic drug used and the associated patient risk factors related to that drug (2,6–9). Even amiodarone may have up to a 1.5% risk of serious proarrhythmia, mostly related to profound bradycardia (10,11). Class I and III anti-arrhythmic drugs are used only rarely during pregnancy because of their uncertain teratogenic effects. In addition, class I and III antiarrhythmic drugs are expensive, with current costs in excess of $100 per mo even with generic drugs. Cost and other factors limit compliance, which in turn limits efficacy. Therefore, alternatives to antiarrhythmic drug approaches or methods to reduce dosage and side effects are greatly needed. Several nonpharmacological approaches to AF management have emerged as a result of the failure of medical approaches. These nonpharmacological approaches include techniques to control the rate and to maintain sinus rhythm (Table 1). This chapter addresses all of these nonpharmacological approaches. Curative radiofrequency catheter ablation is considered in additional detail in Chapter 8.
Source: Contemporary cardiology
Authors: Peter Gallagher, J. Marcus Wharton
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W10380883