The purpose of this study is to evaluate the safety and feasibility of the IV loading strategy in patients who are selected to receive sotalol.

This is an open-label single arm study investigating the safety and feasibility of an intravenous loading regimen of sotalol to initiate patients on oral sotalol therapy. Informed Consent will be obtained from all patients prior to enrollment in the study. Patients will be admitted to the hospital in accordance with standard hospital protocol for oral sotalol loading.

Inclusion Criteria:

• Male and female between 18 - 85 years old
• Recent (within 1 day) cardioversion for atrial fibrillation with scheduled sotalol therapy
• History of highly symptomatic atrial fibrillation who are scheduled for sotalol therapy
• Creatinine clearance ≥60 mL/min
• Subject has provided informed consent prior to initiation of any study-specific activities/procedures

Exclusion Criteria:

• Baseline bradycardia (<50 bpm) off all antiarrhythmic drugs and or Atrioventricular nodal blocking drugs
• Sick sinus syndrome, unless a functioning pacemaker is present.
• Any known sensitivities to beta-blockers
• Uncontrolled heart failure
• Second-degree (Mobitz II, Wenckebach) or third-degree atrioventricular block
• Recent (within 7 days) surgical or catheter ablation procedure
• Severe electrolyte abnormalities (including serum K<3.5)
• Known use of other QTc prolonging drugs (See Appendix A)
• Recent (within 7 days) sotalol use
• Baseline QTc >450 ms
• Severe reactive airway disease - defined as difficulty breathing from bronchial tubes, swelling and overreaction to an irritant
• History of Torsade de Pointes (TdP)
• Pregnancy or breastfeeding
• Left ventricular ejection fraction (LVEF) less than 35%