Interactions between pacemakers and security systems.

Electromagnetic fields arising from a variety of different sources have been shown to interfere with normal pacemaker function. This study evaluated the possible interactions between two modern security systems and different pacemaker types. Fifty–three patients (27 single chamber pacemakers, 25 dual chamber pacemakers) have been tested routinely for their pacemaker function. Thirty–eight patients presented with unipolar sensing and 15 with bipolar sensing. The patients were asked to walk through an installed security system, an antitheft device, and electromagnetic access device with different field strengths while a six–channel ECG monitored the patients. The pacemaker systems were first measured in their basic programmed modes, then the intervention frequency was changed to 100/min and, thereafter, the maximum sensitivity without T wave over– sensing was added. In the security system with the highest field strength (2,700 mA/m), a pacemaker malfunction could be observed in 13% of the monitored patients. In one case, a pacemaker (VVIR) switched to ventricular safety pacing (VOO mode). In the security system with the lower field strength (1,600 mA/m) we found a pacemaker malfunction in 4% of the tested patients. In the antitheft device (50 mA/m). in the electromagnetic access device (300 mA/m), and in pacemaker systems with bipolar sensing, none of these dysfunctions were observed. Phantom programming as described previously did not occur in any of the systems. Persons who are often in the vicinity of security systems should be equipped with a bipolar pacemaker system. Our findings indicate that patients with pacemakers should avoid contact with security systems.