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The need for prophylactic anticoagulation to prevent embolism before direct current cardioversion is performed for atrial fibrillation or atrial flutter is controversial. To examine this issue further, a retrospective review was undertaken to assess the incidence of embolic complications after cardioversion. The review involved 454 elective direct current cardioversions performed for atrial fibrillation or atrial flutter over a 7 year period. The incidence rate of embolic complications was 1.32% (six patients); the complications ranged from minor visual disturbances to a fatal cerebrovascular event. All six patients had atrial fibrillation, and none had been on anticoagulant therapy (p = 0.026). The duration of atrial fibrillation was less than 1 week in five of the six patients who had embolic complications. Baseline characteristics of patients with a postcardioversion embolic event are compared with those of patients who did not have an embolic event. There was no difference in the prevalence of hypertension, diabetes mellitus or prior stroke between the two groups, and there was no difference in the number of patients who were postoperative or had poor left ventricular function. Left atrial size was similar between the two groups. No patient in the embolic group had valvular disease. No patient with atrial flutter had an embolic event regardless of anticoagulant status; therefore, anticoagulation is not recommended for patients with atrial flutter undergoing cardioversion. Prophylactic anticoagulation is pivotal in patients undergoing elective direct current cardioversion for atrial fibrillation, even those with atrial fibrillation of less than 1 week's duration.

MIODARONE, CONSIDERED THE most effective antiarrhythmic drug, was originally developed in the 1960s as an antianginal agent. It was widely prescribed in Europe for angina but serendipitously found to suppress arrhythmias. Argentinian physicians began using amiodarone to treat resistant arrhythmias in the 1970s. 1,2 United States physicians initially obtained amiodarone from Canada and Europe. Under threat of nonshipment from Europe, the US Food and Drug Administration approved amiodarone in 1985 for use in lifethreatening ventricular tachyarrythmias when other drugs are ineffective or poorly tolerated. 3,4 Despite limited indications, amiodarone is one of the most frequently prescribed specific antiarrhythmic drugs in the United States. 5 In this article, we review amiodarone's clinical pharmacology and evaluate evidence supporting amiodarone for treatment and prevention of various arrhythmias, with the goal of motivating clinicians to rigorously evaluate how they prescribe amiodarone. EVIDENCE ACQUISITION We performed a systematic review of peer-reviewed literature using MEDLINE. We searched amiodarone using the terms adverse effects, atrial fibrillation, atrial flutter, congestive heart failure, electrical storm, hypertrophic cardiomyopathy, implantable cardioverterdefibrillator, surgery, ventricular arrhythmia, ventricular fibrillation, and Wolff-Parkinson-White. Studies included all clinical trials, randomized controlled trials, meta-analyses, and other studies with clinical pertinence. Relevant studies compared amiodarone with placebo, other contemporary antiarrhythmic drugs, or nonpharmacological therapies. We limited our search to human-participant, English-language reports published between 1970 and 2007. Bibliographies of identified articles and guidelines from official societies were reviewed for additional references. The search identified 856 articles; of these, CME available online at www.jama.com

BACKGROUND The His-SYNC pilot trial was the first randomized comparison between His bundle pacing in lieu of a left ventricular lead for cardiac resynchronization therapy (His-CRT) and biventricular pacing (BiV-CRT), but was limited by high rates of crossover. OBJECTIVE To evaluate the results of the His-SYNC pilot trial utilizing treatment-received (TR) and per-protocol (PP) analyses. METHODS The His-SYNC pilot was a multicenter, prospective, single-blinded, randomized, controlled trial comparing His-CRT vs BiV-CRT in patients meeting standard indications for CRT (eg, NYHA II-IV patients with QRS .120 ms). Crossovers were required based on prespecified criteria. The primary endpoints analyzed included improvement in QRS duration, left ventricular ejection fraction (LVEF), and freedom from cardiovascular (CV) hospitalization and mortality. RESULTS Among 41 patients enrolled (aged 64 6 13 years, 38% female, LVEF 28%, QRS 168 6 18 ms), 21 were randomized to His-CRT and 20 to BiV-CRT. Crossover occurred in 48% of His-CRT and 26% of BiV-CRT. The most common reason for crossover from His-CRT was inability to correct QRS owing to nonspecific intraventricular conduction delay (n 5 5). Patients treated with His-CRT demonstrated greater QRS narrowing compared to BiV (125 6 22 ms vs Funding: None. Conflicts of Interest: Dr Gaurav Upadhyay has been a speaker for Abbott, Biotronik and Medtronic, and has been a consultant to Abbott, Biotronik, and Medtronic. Dr Pugazhendhi Vijayaraman has been consultant to Abbott, Biotronik, Boston Scientific, and Medtronic; he also has a patent pending for a His delivery tool. Dr Hemal Nayak has been a speaker for Medtronic, Biotronik, and Boston Scientific. Dr Nishant Verma has been a speaker for Biotronik and Medtronic. Dr Gopi Dandamudi has been a speaker and consultant for Medtronic and serves on the advisory board for Biotronik. Dr Parikshit Sharma has been a speaker for Medtronic and has been a consultant for Abbott and Biotronik. Dr Moeen Saleem has been a speaker for Abbott, Medtronic, and Boston Scientific. Dr Faiz Subzposh has been a consultant to Medtronic. Dr Zaid Aziz has been a speaker for Biotronik. Dr Richard Trohman has been a speaker for Abbott, AltaThera Pharmaceuticals, Boston Scientific, Daiichi Sankyo, and Medtronic; he has been an advisor to Boston Scientific; he has received research grants from

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Radiofrequency catheter ablation can be successfully used to eliminate monomorphic ventricular ectopic activity. It may therefore be a reasonable alternative for the treatment of severely symptomatic, drug-resistant monomorphic ventricular ectopic activity in patients without significant structural heart disease.

Development of chronic atrial fibrillation and stroke in paced patients with sick sinus syndrome are strongly determined by clinical variables and secondarily by the pacing modality. Ventricular pacing mode predicts chronic atrial fibrillation in patients with preimplant paroxysmal atrial fibrillation but not in those without it.