Biatrial pacing for paroxysmal atrial fibrillation: a randomized prospective study into the suppression of paroxysmal atrial fibrillation using biatrial pacing.

OBJECTIVES The purpose of this study was twofold: to assess whether biatrial pacing is superior to single-site pacing and capable of reducing the frequency of episodes of paroxysmal atrial fibrillation (PAF); and to compare pacing of the proximal coronary sinus (PCS) with the distal coronary sinus (DCS) and the effects of sequential or simultaneous biatrial pacing. BACKGROUND Interatrial conduction abnormalities have a role in the initiation of PAF. Biatrial pacing alters the site and timing of atrial depolarization and may benefit those with drug-resistant PAF. METHODS Nineteen patients with PAF who were intolerant of or refractory to medication were studied. All received right atrial (RA) and coronary sinus (CS) leads (either PCS or DCS). For three months the pacemaker was set in sensing mode only. Subsequently each patient completed three-month periods in random order in the following modes: RA pacing, CS pacing, biatrial pacing using inter-atrial delays of 15 and 70 ms. RESULTS Sixteen patients received a benefit from one or more pacing modes. The greatest reduction in PAF episodes was seen during biatrial pacing, especially with leads sited at the high right atrium (HRA) and distal CS (p = 0.0048). There was no difference for sequential or simultaneous pacing. Three patients derived no benefit. CONCLUSIONS In selected patients, biatrial pacing causes a significant decrease in atrial fibrillation episodes. Optimal lead sites were at the HRA and DCS. Simultaneous pacing conferred no benefit over sequential pacing.