The programming of dualchamber pacemakers to DDD(R) mode is not recommended in patients with paroxysmal atrial fibrillation/flutter, because the pacemaker detects atrial fibrillation/flutter and paces the ventricle up to the pacemaker's upper tracking rate. Some newer pacemakers have the feature to switch automatically from DDD(R) to DDIR mode at the onset of atrial tachyarrhythmias. The aim of the study was to assess how many patients who received such a new DDDR pacemaker with automatic mode switch can be programmed to DDD(R) mode during follow-up. The dual-chamber pacemaker Thera DR (Medtronic) was implanted for clinical evaluation in 142 patients (65 +/- 16 years, male n = 86; female n = 56). Paroxysmal atrial fibrillation/flutter was present in 54 patients, with an additional 2nd or 3rd degree AV-block in 13 and no high-degree AV block in 22 cases; an AV node ablation was performed in 19 patients. Pacemakers were programmed to DDD(R) mode at discharge in 52 of 53, at month 1 in 44 of 46, and at month 3 in 28 of 30 cases. In respect to the programming to DDD(R) mode there were no statistically significant differences to patients without paroxysmal atrial fibrillation/flutter.
Conclusion: Paroxysmal atrial fibrillation/flutter was present in 38% of the studied patients. During follow up more than 90% of the patients were paced in the DDD(R) mode.