Prevention of paroxysmal atrial fibrillation in patients with sinus bradycardia: role of right atrial linear ablation and pacing site.

Introduction: Right atrial linear lesions (RALL), either alone or in combination with antiarrhythmic drug therapy, may modify the substrate for maintenance of atrial fibrillation (AF). The aim of this prospective randomized study was to determine whether RALL provides additional benefit to right atrial appendage pacing (RAAP) and/or interatrial septum pacing (IASP) and drug therapy in patients with symptomatic paroxysmal AF and sinus bradycardia requiring permanent atrial pacing. Methods and Results: Sixty-four patients (33 men and 31 women, mean age 73 ± 10 years) completed the 6-month follow-up. Patients were randomized to either RALL (n = 33) or non-right atrial linear lesions (NRALL), and then to either IASP (n = 32) or RAAP (n = 32). Fifteen RALL patients were paced at the IAS and 18 at the RAA. Seventeen NRALL patients were paced at the IAS and 14 at the RAA. No statistical difference was observed with regard to the mean atrial tachyarrhythmia (AT) burden between NRALL (84 ± 169 min/day) and RALL patients (202 ± 219 min/day). Mean AT burden was significantly lower in the IASP group (70 ± 150 min/day) than in RAAP group (219 ± 317 min/day; P < 0.016). In the RALL group, the mean AT burden was 99 ± 180 min/day in the IASP patients and 288 ± 372 min/day in the RAAP patients (P < 0.046). In the NRALL group, no statistical difference in the mean AT burden was observed between IASP patients (46 ± 117 min/day) and RAAP patients (130 ± 211 min/day). Conclusion: The results of the present study indicate that RALL did not provide any additional therapeutic benefit to combined antiarrhythmic drug therapy and septal or nonseptal atrial pacing in patients with sinus bradycardia and paroxysmal AF. (J Cardiovasc Electrophysiol, Vol. 14, pp. 733-738, July 2003)