ATRIAL FIBRILLATORY ELECTROGRAM MEASUREMENT ALLOWS ATRIAL LEAD PLACEMENT IN PATIENTS WHO DEVELOP ATRIAL-FIBRILLATION DURING PERMANENT DUAL-CHAMBER PACEMAKER IMPLANTATION

The benefit of DDD(R) pacing is proven even in patients with intermitt ent atrial fibrillation. Atrial fibrillation developing during dual ch amber pacemaker implantation creates a difficult problem. Maneuvers to reestablish a stable atrial rhythm often are required if atrial fibri llation sets in. This study was performed to determine if atrial lead placement can be performed with acceptable long-term results in the pr esence of atrial fibrillation. Twenty-one patients in whom atrial fibr illation developed during permanent pacemaker implantation were includ ed in this study. In 12 patients, episodes of intermittent atrial fibr illation had been documented before the procedure. Screw-in leads were used in 15 patients and J-shaped passive fixation leads in 6 patients . All leads were bipolar. The intraoperative atrial fibrillation elect rogram amplitudes ranged from 0.9 to 3.2 mV (mean 1.8 +/- 0.6 mV). One patient required lead revision due to a high atrial pacing threshold after conversion to SR. One patient remained in atrial fibrillation at 3-month follow-up. The other 20 patients converted to SR, 11 of whom had intermittent atrial fibrillation with successful mode switch activ ation. P wave amplitudes were 2.8 +/- .6 mV (range 1.4 to 4.0 mV) afte r conversion to SR. The mean atrial pacing threshold wets 1.1 +/- 0.5 V (range 0.5 to 3.5 V). Placement of atrial leads in patients who deve lop atrial fibrillation during pacemaker implantation is feasible; fib rillatory electrogram amplitudes showed a good correlation with the at rial signal after conversion to an organized atrial rhythm (r = 0.698) . Acceptable atrial pacing thresholds can be expected as well.