Drug and electrical therapy of supraventricular tachyarrhythmias

This article reviews current pharmacological and electrical approaches to the restoration of sinus rhythm in patients who suffer from atrial fibrillation and atrial flutter. Spontaneous conversion to sinus rhythm occurs in a high proportion of atrial fibrillation of < 24 h duration. Among patients presenting with atrial fibrillation, which was clinically estimated to have lasted < 48 h, the likelihood of cardioversion-related clinical thromboembolism is low, which supports the current practice of early cardioversion without anticoagulation. Antiarrhythmic drugs effective in terminating atrial fibrillation of short duration are those which possess class IA, IC and III properties. Electrical transthoracic cardioversion by using different electrode positions and additional pressure over the electrodes during shock delivery is a highly effective and well-tolerated method in restoration of sinus rhythm even in patients under conscious sedation. Immediate spontaneous reinitiation of atrial fibrillation can occur in a significant proportion of patients undergoing electrical cardioversion and can be reduced after a pretreatment with antiarrhythmic drugs. In patients with failed external cardioversion, internal low energy cardioversion offers an effective option for restoring sinus rhythm. After cardioversion in a high proportion of patients antiarrhythmic drugs are necessary to prevent atrial fibrillation from recurring. A serial cardioversion approach can prevent the evolution of permanent atrial fibrillation in a subgroup of patients. Overdrive atrial pacing is an effective and minimally invasive procedure for termination of atrial flutter. The acute administration of class IA, IC and III antiarrhythmic drugs increases the success rate of this method in restoring sinus rhythm.