Followup of implanted pacemakers: an evaluation of surveillance methods

A waveform analysis clinic augmented by telephone transmission of pacemaker interval in the late stages of pacemaker life will yield a considerable amount of information and will permit elective replacement of pacemakers in about 90 per cent of cases. The clinic has an advantage over other surveillance systems in the accuracy of the diagnosis, the identification of abnormalities that do not require pacemaker replacement, and the multiple benefits of a direct doctor-patient relationship. No system of surveillance can be recommended over all others in all circumstances. It is sufficient here to indicate the merits of each system and to allow the various centers to develop according to their own particular needs and desires. There is no objection to telephone monitoring alone as long as one realizes that only about 80 per cent of the problems can be detected and that there will be an irreducible percentage of false negative and false positive diagnoses. The danger of errors of this type is not great, but it does exist and should be avoided if possible. Other methods of pacemaker followup, such as simple examination and an electrocardiogram in a doctor's office or changing the pacemaker on the basis of the manufacturer's prediction, are relatively unsatisfactory. It should be stressed that pacemaker surveillance of some type is essential to satisfactory patient care because it provides for maximum utilization of the pacemaker, for replacement only if and when necessary, for detection of 90 per cent of pacemaker problems, and for protection of the patient against unexpected pacemaker failure.