Permanent pacemaker trends in Singapore General Hospital in the eighties

This is a ten year survey of all the pacemakers implanted in the Department of Cardiology, Singapore General Hospital, from January 1980 to July 1989. There were 331 (164 male and 167 female) patients with pulse generators and leads implanted. The ages of the subjects ranged from 8 to 91 years (mean 63 years). Two-thirds of the patients were greater than 60 years. The indications for pacemaker implants were high grade atrioventricular block in 199 (60%) patients, sick sinus syndrome in 112 (34%) patients and in the remaining 20 (6%) of patients, no data was available, 298 (90%) patients had VVI pacing (133 were non-programmable and 165 were programmable pacemakers), 8 (2%) had AAI, 16 (5%) had DDD and the remaining 9 (3%) had VVIR mode of pacing. 282 (85%) of the patients had new pacemakers implanted while the remaining 49 (15%) patients had pacemaker replacements. At the time of replacement of pacemakers, 23 patients had upgrade of their non-programmable to programmable VVI pacemakers and 4 to DDD and VVIR pacing modes respectively. Furthermore, 293 (88%) patients had endocardial leads as compared to 38 (12%) with epicardial leads. In conclusion, most of the patients who require pacemaker implants will continue to have single chamber system. However, to improve longevity of the pacemakers, one should consider using low pacing threshold leads and programmable pacemakers.