Dual-Site Atrial Pacing for Atrial Fibrillation in Patients without Bradycardia

Atrial pacing has been shown to delay the onset of atrial fibrillation ( AF) when compared with ventricular pacing in patients with sick sinus syndrome. The role for pacing in the control of AF in patients without bradycardia is uncertain. We performed a randomized, crossover, single- blinded study in 22 patients (14 women, aged 63 +/- 10 years ) with paroxysmal AF refractory to treatment with oral sotalol (202 +/- 68 mg/day ) and no bradycardic indication for pacing. All patients received a dual- chamber pacemaker with 2 atrial pacing leads positioned at the high right atrium and coronary sinus ostium, respectively. Patients were randomized in a crossover fashion to be paced for 12 weeks, either with high right atrial (RA) pacing at 30 beats /min ("Off") or dual-site RA pacing with an overdrive algorithm that maintained atrial pacing at a rate slightly above the sinus rate ("On"). Treatment on resulted in a significantly higher percentage of atrial pacing and a reduction in atrial ectopic frequency than the treatment off period. The time to the first clinical AF recurrence was prolonged (15 +/- 17 to 50 +/- 35 days, p = 0.006), and total AF burden was reduced (45 +/- 34% vs 22 +/- 29%, p = 0 .04) in the on-treatment phase. However, there was no difference in AF checklist symptom scores or overall quality -of-life measures. Dual-site RA pacing with continued sinus overdrive prolonged the time to AF recurrence and decreased AF burden in patients with paroxysmal AF. The absence of a major impact on symptom control suggests that pacing should be used as an adjunctive therapy with other treatment modalities for AF. (C) 2001 by Excerpta Medica, Inc.