Clinical Research Directory

Inclusion Criteria: * 18 to 80 years of age * Sustained AF of \> 2 hours and \< 72 hours duration * Eligible for cardioversion (electrical and pharmacologic) * On adequate anticoagulant therapy or eligible for anticoagulation during treatment and for at least 30 days duration after treatment if indicated by ACC/AHA/HRS or country specific national or international guidelines for thromboembolic risk reduction related to AF Exclusion Criteria: * Atrial fibrillation \< 2 hours or \> 72 hours duration or with duration not reliably established at the time of dosing * Hemodynamic instability that may require emergency electrical cardioversion * Atrial flutter * Moderate to severe HF * Clinical or ECG signs of acute cardiac ischemia or digitalis toxicity * Known or suspected hyperthyroidism * Cardiac surgery, stroke, TIA, acute MI/ PCI, unstable angina, or persistent angina at rest within the previous 3 months * Presence of LA thrombus by TEE or TTE * Presence of concurrent myocarditis or endocarditis * ECG abnormalities: Current QTcF \> 480 msec; QRS interval \> 120 msec and/or a complete bundle branch block (BBB)l Delta wave or other pre-excitation pattern consistent with WPW syndrome; Acute coronary ischemia patterns * Use of medication that prolongs the QTc interval or history of: Long QT syndrome, congenital or acquired; Torsades de Pointes (TdP); Brugada Syndrome; Ventricular arrhythmia (not including infrequent isolated PVC) * Concurrent treatment with Class I or III antiarrhythmic drugs, metformin or strong CYP2D6 inhibitors (unless the medication is discontinued \> 5 half-lives before enrollment) * Treatment with oral amiodarone in the previous 3 months or IV amiodarone administered within 24 hours prior to planned Study Drug administration * Use of vernakalant, or any experimental drug within 30 days or five half-lives (whichever is longer) of Study Drug administration, or use of an invasive investigational medical device within 2 months prior to Study Drug administration, or current enrollment in another study with investigational agent or procedure * Clinically significant laboratory abnormalities