• Primary Outcome - Decreased recurrence of Atrial Fibrillation [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  To determine if ranolazine is effective in decreasing recurrences of AF in patients with persistent AF successfully treated with electrical cardioversion.
  
  

• Secondary Outcome - Efficacy in preventing hospitalizations for symptomatic Atrial Fibrillation [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  To evaluate the efficacy of ranolazine in preventing hospitalizations for symptomatic AF. We will follow the patients at 2 weeks, 1, 3 and 6 months after randomization, with an outpatient office visit. At each visit, patients will have a brief history and physical examination, any cardiovascular events, including hospitalizations for symptomatic AF, will be recorded and a 12-lead electrocardiogram will be obtained to assess maintenance of sinus rhythm.
  
  

Atrial fibrillation (AF) is the most common clinically significant cardiac arrhythmia and is associated with increased cardiovascular morbidity and mortality. Although a rhythm control strategy offers no survival benefit over a rate control strategy, elective electrical cardioversion is still recommended in patients without hemodynamic instability for symptomatic relief. However, recurrences are frequent after cardioversion and antiarrhythmic medications are required to maintain sinus rhythm. Nonetheless, the use of antiarrhythmic medications is problematic because of the risk of serious potential adverse effects, including drug-induced ventricular arrhythmias.

Ranolazine is a novel antianginal agent, which inhibits the late inward sodium current and produces antiischemic effects without reducing heart rate or blood pressure. Additionally, recent preclinical as well as preliminary clinical data suggest that ranolazine exhibits distinct antiarrhythmic properties. However, there is no controlled data for the use of ranolazine to prevent recurrence of AF after electrical cardioversion of persistent AF.

The investigators hypothesize that ranolazine would decrease the incidence of recurrence of AF after electrical cardioversion of persistent AF. Patients with persistent AF who are candidates for electrical cardioversion will be randomized to either placebo or ranolazine after successful electrical cardioversion. They will be followed at 2 weeks, 1, 3 and 6 months for clinical evaluation and electrocardiography for the detection of recurrence of AF.