Oral ranolazine in the conversion of paroxysmal and initial onset atrial fibrillation.

ABSTRACT

Background: Atrial fibrillation (AF) is the most common arrhythmia requiring treatment. High-dose oral anti-arrhythmics (mainly class 1C or quinidine) are used as “pill in the pocket” approach to convert recent onset AF. However pro-arrhythmic risk has limited the application of this approach in many patients. Ranolazine, an antianginal agent, which inhibits abnormal late Na+ channel currents, decreases sodium-calcium overload, potentially inhibits after-depolarisations which have been implicated in the initiation and propagation of AF. Methods: Two gramme ranolazine was given orally to 40 patients with new (first detected episode of AF, 16 patients) or paroxysmal (3 hours to 72 hours duration, 24 patients) AF. Twenty-four patients were in hospital, 6 in office, and 10 at home at the time of ranolazine administration. Age, sex, associated health condition, structural heart disease (SHD) and echocardiographic criteria were recorded. Treatment for other related conditions was also given. Successful conversion was defined as restoration of sinus rhythm within 6 hours of ranolazine administration. Results: Twenty-six of 40 patients (65%) converted to sinus rhythm. No pro-arrhythmic effects, haemodynamic instability, adverse effects, or perceived intolerance were noted. Conclusion: High-dose oral ranolazine shows utility as a possible safe agent to convert new or paroxysmal AF.