Influence of D-net (EUROPEAN GSM-standard) cellular telephones on implanted pacemakers in children

This study was designed to evaluate possible. interactions between digital cellular telephones and implanted pacemakers in children. The study comprised 95 patients (53 males and 42 females) with a mean age of 11.5 +/- 4.6 years (range 1-22 years). The average time from pacemaker implantation was 2.5 years (range 1 month-12 years), Fourteen (15%) devices were dual chamber and the remaining were single chamber pacemakers, The following companies manufactured the pacemakers tested: Medtronic (n = 42), Telectronics (n = 9), Vitatron (n = 16), Pacesetter (n = 19), CPI (n = 8), and Biotronik (n = 1). All the patients were tested in the supine position during continuous ECG monitoring. After completion of the routine pacemaker check, the effects of the European Global system for mobile communication (GSM) was tested using two cellular telephone models (Ericsson GA 628 and Siemens S 25, 2-W power). For this purpose, atrial and ventricular sensitivity settings were programmed to the most sensitive values, and the tests were carried out in the unipolar and bipolar sensing modes. The evaluation was performed during ringing, switching on/off, and conversation phase with the cellular telephone positioned over the pulse generator and around the pacemaker pocket. A malfunction of the pacemaker was not observed in any patient. Only, 1 (1%) of 95 patients showed a brief oversensing problem during calls with the cellular telephone. In this case, an AAIR pacemaker was implanted transvenously in a subcutaneous pocket and the sensing defect occurred only with the unipolar sensing mode and was not reproducible. Once the source of interference was removed, no sensing defect was detected and the patient remained asymptomatic. No symptoms were experienced in this study. The authors believe that pacemaker dependent patients with nonprotected pulse generators manufactured at the beginning of 1990s may be tested by their physicians for possible interferences before they use a digital cellular telephone.