Symptomatic arrhythmia recurrence as an outcome in clinical trials of antiarrhythmic drug therapy.

Atrial fibrillation is the most common cardiac arrhythmia requiring medical treatment, and developing new antiarrhythmic therapies remains a challenging problem. Documenting symptomatic arrhythmia recurrence using patient-activated ECG recording has been a useful tool to test new pharmacologic therapies. This technique has been used successfully to test immediate-release verapamil in patients with paroxysmal supraventricular tachycardia; flecainide acetate in patients with atrial fibrillation and paroxysmal supraventricular tachycardia; immediate-release propafenone in patients with atrial fibrillation and paroxysmal supraventricular tachycardia; d,l-sotalol in patients with atrial fibrillation; digoxin in patients with atrial fibrillation; azimilide dihydrochloride in patients with atrial fibrillation; and sustained-release propafenone in patients with atrial fibrillation. These studies have contributed to understanding efficacy and have led to regulatory approvals in the United States to label drugs as effective for supraventricular arrhythmias.