Atrial selective effect of amiodarone to increase threshold of excitation.

Increases of pacing threshold stimulation are well documented with different antiarrhythmic drugs, but not with amiodarone. We report a case of a patient with dual-chamber pacing, with stable thresholds on repeated measurements on the last year, who presented severe increase of atrial pacing threshold resulting in loss of atrial capture after a year of treatment with amiodarone. Thresholds were normalized once amiodarone was removed.

Clinical effectiveness of antiarrhythmic treatment after electrical cardioversion in patients without structural heart disease.

Introduction And Objectives: The aim was to investigate the clinical effectiveness of using antiarrhythmic drugs after electrical cardioversion in patients without structural heart disease, including their effect on the maintenance of sinus rhythm.

Methods: In total, 528 patients with persistent atrial fibrillation but without significant structural heart disease who underwent successful electrical cardioversion at 96 Spanish hospitals were followed up for 1 year. Patients were assessed at 1, 3, 6 and 12 months.