Is left atrial appendage occlusion useful for prevention of stroke or embolism in atrial fibrillation?

Since in atrial fibrillation more than 90% of the thrombi are located in the left atrial appendage, an "elimination" of the left atrial appendage, either by resection or occlusion, seems an attractive alternative to oral anticoagulation. Although frequently regarded as an useless appendage, data from animal and human investigations show that the left atrial appendage may play an important role in the maintenance and regulation of the cardiac function, especially in arterial hypertension, atrial fibrillation, coronary heart disease, valvular heart disease and heart failure. Elimination of the left atrial appendage may impede thirst in hypovolemia, deteriorate hemodynamic responses to volume or pressure overload, decrease cardiac output and promote heart failure. Instead of preventing stroke, the consequences of left atrial appendage elimination may create new risk factors for stroke and thus might induce more harm than benefit to patients with atrial fibrillation. As long as the physiologic and pathophysiologic role of the left atrial appendage is not fully understood, left atrial appendage elimination should not be an alternative to oral anticoagulation.     

Does advanced age affect the immediate and long-term results of direct-current external cardioversion of atrial fibrillation?

OBJECTIVES: To determine whether advanced age affects the immediate and long-term results of direct-current external cardioversion (ECV) of atrial fibrillation (AF), the sustained arrhythmia most commonly encountered in older patients. DESIGN: Retrospective analysis of medical records. SETTING: Intensive care unit. PARTICIPANTS: Two hundred fifty consecutive patients(age 34-100) with AF who underwent ECV following a standardized protocol in an intensive care unit. MEASUREMENTS: Immediate efficacy of ECV, defined as recovery of sinus rhythm, and maintenance of sinus rhythm over the follow-up were study outcomes. The univariate and multivariate associations of immediate efficacy of ECV and long-term results with clinical variables were analyzed. RESULTS: At univariate analysis, immediate efficacy of ECV (overall, 91.2%) was lower in older patients and in those with chronic obstructive pulmonary disease, higher for a 3- to 90-day pre-ECV duration of AF than for a duration of 2 days or less or more than 90 days, and independent of underlying cardiac disease, hypertension, diabetes mellitus, previous AF, and left atrial dimension. However, pre-ECV duration of AF was the only multivariate predictor of ECV immediate success. Major complications occurred in only three patients. Of 220 patients discharged in sinus rhythm, 211 were followed up for a mean period +/- standard deviation of 34 +/- 25 months. AF relapsed in 45.5% of them. At multivariate analysis, underlying cardiac disease was the only predictor of the relapse rate, and relapse rate was lower in coronary heart disease than in valvular heart disease, congestive heart failure, or lone AF. CONCLUSION: Immediate and long-term results of ECV of AF, an effective and safe procedure, are unaffected by age,at least after adjusting for several covariates.     

Is discharge to home after emergency department cardioversion safe for the treatment of recent-onset atrial fibrillation?

Recent-onset atrial fibrillation, defined as a first detected or recurrent episode of atrial fibrillation lasting less than 48 hours, is a commonly encountered dysrhythmia in the emergency department (ED). Cardioversion of stable patients in the ED with recent-onset atrial fibrillation without antecedent anticoagulation would allow for these patients to be discharged directly to home. We searched the literature to determine whether any studies have investigated the safety of this management strategy and identified five that addressed this question. These studies are reviewed herein; importantly, not one ED patient who was cardioverted in any of the five studies suffered a thromboembolic event - the feared complication responsible for most of the controversy surrounding the ED management of atrial fibrillation. According to the available evidence, we conclude that it would be within the standard of care to discharge home stable patients with recent-onset atrial fibrillation after cardioversion in the ED with adequate follow-up. It should be noted that although this strategy is safe and effective, the return visit rate for relapsed atrial fibrillation is 3% to 17%, and patients should be made aware of this possibility.     

Therapeutic implications of atrial fibrillation mechanisms: can mechanistic insights be used to improve AF management?

Atrial fibrillation (AF) is a very common clinical problem, and presently available treatment options are suboptimal. A tremendous amount has been learned over the past 10 years about the atrial substrates that support sustained AF at the tissue, ionic and molecular levels. This understanding of the fundamental mechanisms underlying AF has opened up a variety of new, rationally-based therapeutic approaches. The present paper reviews what is known about the mechanistic substrates that lead to AF and discusses the potential therapeutic consequences.