Dual site right atrial pacing in the prevention of symptomatic atrial fibrillation refractory to drug therapy and unrelated to sinus bradycardia.

Abstract

Dual-site right atrial pacing has been shown recently to prevent atrial fibrillation relapses in patients affected by drug-refractory, highly-recurring tachyarrhythmia, associated to sinus bradycardia. The aim of our study was to verify whether this stimulation modality could be useful in patients affected by refractory atrial fibrillation unassociated to sinus bradycardia. Fifteen patients (6 males) affected by refractory, symptomatic atrial fibrillation, and potential candidates to AV node ablation, were prospectively enrolled. Mean age was 65 +/- 5 years (range 62-78). Associated pathology was arterial hypertension in 12, and dilated cardiomyopathy in 3. Eight patients were affected by persistent atrial fibrillation, and seven by paroxysmal atrial fibrillation. The duration of the arrhythmia was 61 +/- 63 months (range 3-216). Left atrial diameter was 39.4 +/- 4.2 mm (range 33-46), left ventricular end-diastolic diameter was 52.4 +/- 12.2 mm (range 41-90), and left ventricular ejection fraction was 55 +/- 16 (range 18-81). Single chamber atrial pacing was used in 10 patients, dual chamber in 5 patients. The mean duration of follow up was 24 +/- 12 months (range 3-41). During this period the number of episodes of atrial fibrillation decreased from a mean of 13 +/- 38 (range 1-150) to 0.4 +/- 0.7 (range 0-2.3) per month (p < 0.001). In the subgroup of patients with persistent atrial fibrillation the number of episodes decreased from a mean of 20.4 +/- 52.4 (range 1-150) to 0.6 +/- 0.9 (range 0-2.3) (p < 0.001). In patients with paroxysmal atrial fibrillation the number of episodes decreased from 4.6 +/- 3.5 (range 2-12) to 0.2 +/- 0.5 (range 0-1.4) (p < 0.001). One patient (6.7%) developed chronic atrial fibrillation 16 months after the implant, 2 remaining patients (13%) had their arrhythmia unaltered. After the implant the number of Class 1 antiarrhythmic drugs fell from 18 to 6 (p < 0.001) and that of Class 2 changed from 0 to 7 p < 0.001). The use of Class 3 and 4 did not change significantly. No complications related to implant were observed. Permanent dual-site right atrial pacing can prevent atrial fibrillation recurrences in patients affected by highly symptomatic episodes unassociated to sinus bradycardia.