The role of class III antiarrhythmic agents in maintaining sinus rhythm.

The last decade has seen considerable changes in both attitude and approach to the management of arrhythmia. Much of this has resulted from trials such as the CAST (Cardiac Arrhythmia Suppression Trial) and the CASH (Cardiac Arrhythmia Study Hamburg), which demonstrated the potentially lethal consequences of using class I sodium channel blockers in patients with structural heart disease. The subsequent popularity of the class III agents and recognition that they are the best available therapy has led to the popularity of amiodarone and sotalol in the treatment of arrhythmia. Although these agents can achieve good efficacy in the suppression of atrial fibrillation their use is not without problems. Sotalol requires careful patient selection due to the risk of proarrhythmia and although cardiac effects are rare with amiodarone therapy, potentially serious non-cardiac adverse effects can limit the long-term use of this agent. Although treatment guidelines have helped to clarify our current knowledge and outline appropriate clinical application of antiarrhythmic agents, the need for antiarrhythmic agents which marry efficacy with improved safety and clinical applicability is apparent.