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Long‐Term Survival of Chosen Atrial‐Based Pacing Modalities

Atrial‐based cardiac pacing modalities were chosen in 341 of 684 (50%) patients selected for permanent cardiac pacing at the Grey Nuns Community Health Center between 1989 and 1995. There were 183 males and 158 females. Mean age was 70 years (range 8–97 years). The indications for atrial‐based pacing were: advanced atri‐ oventricular (AV) block (n = 166) 49%; sick sinus syndrome (n = 153) 45%; hypersensitive carotid sinus syndrome (n = 11) 3%; neurocardiac syncope (n = 10) 2.9%; and hypertrophic cardiomyopathy (n = 1) 0.3%. Forty‐eight patients had a known history of paroxysmal atrial arrhythmias. All patients had routine follow‐up performed at 24 hours, 7 days, 6 weeks, 3 months, and then 6 biannuallv. Mean follow‐up was 6.5 years (range 1 month to 12 years). Observed survival of the programmed atrial‐based modality was compared to the original mode chosen at the time of implantation. Thirty‐five of 37 (95%) chosen for AAIR modes remain programmed AAIR. Twenty‐two of 24 (92%) chosen for VDDR modes remain programmed VDDR. Two hundred and fifty‐five of 280 (91 %) chosen for DDD or DDDR modes remain programmed DDDR. Two of 37 (5%) patients originally implanted with AAI pacing systems were upgraded to DDDR mode due to new onset AV block. One of 24 (4%) patients originally implanted with a VDDR pacing system was upgraded to DDDR due to loss of atrial sensing of the single pass lead. Twenty‐six of 304 (8.5%) patients originally implanted with DDD/DDDR (n ‐ 25) and VDDR (n = 1) pacing systems were reprogrammed to VVI or WIR: 16 (62%) due to sustained refractory atrial arrhythmias; 5 (19%) due to atrial lead malfunction; and 5 (19%) due to reasons unrelated to the pacing system. With careful review of the patients' conduction disorder and appropriate selection of pacing modality, the observed survival of long‐term atrial‐based pacing remains at 92% when compared to the chosen modality at the time of implantation. Atrial‐based pacing may be used to reduce the incidence of atrial dysrhythmia with careful programming of the base atrial pacing rates.