Need For Electrical Cardioversion Research Articles

Multisite atrial pacing: an option for atrial fibrillation prevention? preliminary results of the Dutch dual-site right atrial pacing for prevention of atrial fibrillation study

Multisite pacing is a novel concept for the prevention of recurrent drug-refractory atrial fibrillation (AF). Two different pacing methods have been described, biatrial pacing and dual-site right atrial stimulation. The use of multisite pacing as preventive therapy for recurrences of atrial fibrillation is still under investigation. We conducted a prospective, randomized, crossover study in patients with recurrent drug-refractory AF without or with minimal structural heart disease. After implantation of a DDD pacemaker, patients were randomized to either dual-site pacing first (Group I) or single-site (high right atrium) pacing first (Group II) and, after 6 months of treatment, the device was reprogrammed to the other pacing mode. Preliminary results of 13 patients in each group are presented. Clinical characteristics of patients in both groups with respect to age, sex, left atrial dimension, left ventricular function, and New York Heart Association (NYHA) functional class were comparable. Pacing therapy was combined with antiarrhythmic drug treatment. After completion of the study protocol, the arrhythmia-free interval was not remarkably different in either group. However, the endpoint free interval (i.e., the need for electrical cardioversion because of recurrent AF lasting >24 hours, was less during dual-site pacing in Group II. Within 6 months, 43 patients enrolled in this study will have completed the protocol.

Efficacy, Safety, and Determinants of Conversion of Atrial Fibrillation and Flutter With Oral Amiodarone

Amiodarone is effective for long-term maintenance of sinus rhythm after electrical cardioversion of refractory atrial fibrillation or flutter. To examine its efficacy and safety for pharmacologic conversion of these arrhythmias, we studied 129 patients with refractory atrial fibrillation or flutter who had failed previous intensive conventional antiarrhythmic treatment. In anticipation of electrical cardioversion, patients were loaded with amiodarone, 600 mg/day during a 4-week period. The main outcome measure was pharmacologic conversion during this period. During the loading period, 23 patients (18%) converted to sinus rhythm. When analyzed in a multivariate model, conversion was related to desethylamiodarone plasma level (p = 0.0006), arrhythmia duration (p = 0.04), left atrial area (p = 0.02), and concomitant treatment with verapamil (p = 0.01). During ongoing atrial fibrillation after loading, the ventricular rate decreased from 100 ± 25 to 87 ± 27 beats/min (p < 0.001). Amiodarone appeared to be safe and did not have to be discontinued because of intolerable side effects. Thus, amiodarone loading is safe and is still able to convert refractory atrial fibrillation or flutter. Conversion is related to increased desethylamiodarone plasma levels and concomitant treatment with verapamil. Because prolonged loading may increase desethylamiodarone plasma concentrations, this may enhance efficacy and obviate the need for electrical cardioversion.