Blind atrial pacing for patients with sinus node disease who develop atrial fibrillation during permanent pacemaker implantation.

During a 6-year period, six of 110 patients implanted with AAI pacemakers for sick sinus syndrome developed atrial fibrillation at the time of pacemaker implantation (5.5%). In all cases a passive fixation lead was sited in the right atrial appendage, its stability being ensured by rotation of the lead and phrenic nerve stimulation excluded by pacing at 10 V. One patient remained in chronic atrial fibrillation. In the other five, who subsequently reverted to sinus rhythm, atrial P-wave sensing and lead threshold values were satisfactory, allowing programming of the pacemaker output down to 2.5 V to conserve the battery. One out of these five patients continued to have intermittent atrial fibrillation. We conclude that in sick sinus syndrome, atrial fibrillation complicates AAI pacemaker implantation procedure in 5.5% of cases. As an alternative to an unplanned general anaesthetic to cardiovert the patient, it is reasonable to implant an atrial lead in the right atrial appendage in the expectation of a spontaneous reversion to sinus rhythm with a good lead threshold and P-wave sensing. In contrast to inappropriate pacing of the right ventricle in VVI mode, this strategy avoids pacemaker syndrome and reduces the risk of subsequent attacks of atrial fibrillation.