A pilot study on the acute conversion and maintenance of sinus rhythm in rheumatic atrial fibrillation using oral...

Achievement of sinus rhythm (SR) is an important goal in rheumatic atrial fibrillation (AF). Studies in rheumatic AF have often used amiodarone for rhythm control. Flecainide has not been studied in these patients due to concerns of underlying structural heart disease.

Pharmacological cardioversion by oral single loading dose (SLD) of Flecainide (4 mg/kg, ≤300 mg) was tested in 50 patients with rheumatic AF (MVA 1.51 ± 0.19 mm², age 46.2 ± 10.28 yrs, AF duration 3.10 ± 1.7 yrs, LA size: 44.42 ± 7.48 mm). Non-converters underwent DC cardioversion (DCC) at 24 h. All patients received oral flecainide and ββ/diltiazem at discharge.

At 24 h, 38/50 (76%) achieved SR (2 with SLD; 36 after DCC). At 30 days (mean Flecainide dose 116.5 ± 10.5 mg) successful maintenance of SR was noted in 31/38 (89%). At 1 year, 30/38 (79%) of the initial converters and 60% of the overall population maintained SR. Those in SR had significantly better NYHA Class (1.1 ± 0.12 vs 1.3 ± 0.10, p = 0.03) and mean PCS8 score (50.11 ± 5.337 vs 46.84 ± 5.379, p = 0.02). AF duration (OR 0.594 CI 0.375-0.940, p = 0.02) and LA size (OR 0.840, CI 0.757-0.933, p = 0.001) were found to be the only significant predictors of successful outcomes. Patients with AF duration <3.5 years and LA size <51 mm had 85% and 75% chance of maintaining SR at 1 year, respectively.

Flecainide is safe and effective for achieving and maintaining SR in patients of rheumatic AF who are unlikely to have underlying coronary artery disease or ventricular dysfunction.