HOSPITAL PAGER SYSTEMS MAY CAUSE INTERFERENCE WITH PACEMAKER TELEMETRY

Electromagnetic interference (EMI) is a well-known cause of pacemaker dysfunction. The communication between pacemakers and programmers, ena bled by telemetry, is also susceptible to EMI. We have observed that h ospital pager systems have the potential to interfere with pacemaker t elemetry Measurements in our pacemaker clinic and in a technical labor atory have shown that inductive pager systems may disturb telemetry in the form of inaccurate battery voltage, current and impedance measure ments, disturbances in intracardiac electrogram tracings, or total int erruption of telemetric communications. The reason for EMI was an over lap of carrier frequencies of some pacemaker programmers (32-37 kHz) w ith those of our inductive pager system (36.22 kHz). Radiofrequency pa ger systems using higher frequencies (in MHZ range) are unlikely to ca use such interference. Awareness of this interference potential may ha ve practical implications in choosing the carrier frequencies of induc tive hospital pager systems, as well as pacemaker programmers, and in planning the location of pacemaker clinics.