A comparison of AAIR versus DDDR pacing for patients with sinus node dysfunction: a long-term follow-up study

The aim of the study was to compare the clinical outcomes [atrial fibrillation (AF), atrio-ventricular (AV) block, device sepsis and lead revision] of patients with sinus node dysfunction (SND) between atrial-pacing atrial-sensing inhibited-response rate-adaptive (AAIR) versus dual-chamber rate-adaptive (DDDR) pacing. The choice of AAIR pacing versus DDDR pacing was determined by AV nodal functional testing at implant.

We conducted a retrospective review of consecutive patients who underwent AAIR and DDDR pacing over a 10-year period.

One hundred and sixteen patients required pacing for symptomatic SND. Fifty-four (46.6%) patients received AAIR pacemakers and 62 (53.4%) received DDDR pacemakers based on AV nodal functional testing at implant. Patients who had AV Wenkebach with atrial pacing at 120 beats per minute received DDDR pacing. Overall the mean age of patients with SND was 65 years and 66.4% were females, 30% were diabetics and 71% were hypertensives. Pre-syncope/syncope (84%) and dizziness (69%) were the most common symptoms. Sinus pauses and sinus bradycardia were the most common ECG manifestations. Over a median follow up of five (IQR: 2-11) years, four patients (7.4%) developed AF in the AAIR group compared to three (4.8%) in the DDDR group (p = 0.70). AV block occurred in one patient in the AAIR group, who required an upgrade to a DDDR pacemaker. There was no difference in device sepsis or need for lead revision between the two groups.

We found that AV nodal functional testing with atrial pacing at the time of pacemaker implantation was a useful tool to help guide the implanter between AAIR or DDDR pacing. Patients who underwent AAIR pacing had a low risk of AF, AV block or lead revision. In resource-limited settings, AAIR pacing guided by AV nodal functional testing should be considered as an alternative to DDDR pacing.