Observations on the safety and effectiveness of dofetilide in patients with paroxysmal atrial fibrillation and normal left ventricular function.

Dofetilide is currently recommended as second-tier therapy to maintain sinus rhythm in patients with paroxysmal atrial fibrillation (PAF) and normal left ventricular function, yet limited data support this recommendation. We examined the safety and efficacy of dofetilide in this setting through a retrospective chart review. We evaluated patients who had symptomatic PAF, normal left ventricular function, and no significant valvular disease. The end points were complete suppression of symptomatic PAF and subjective symptomatic improvement with dofetilide treatment. Over a 3-year period, 34 patients who had failed previous antiarrhythmic therapy were included. Of these, 3 discontinued dofetilide treatment before discharge. Of the remaining 31 who continued treatment after discharge, it was eventually discontinued in 13. At 12 months, symptomatic improvement was observed in 18 of 31 patients, 6 of whom remained asymptomatic. Treatment with dofetilide in this study was successful in less than 1 in 5 patients. Despite careful precautions, serious proarrhythmias, the major limiting side effect of dofetilide, still occurred during long-term follow-up.