[Behavior of 20 pacemakers as patients pass through 2 models of theft-detection doors].

Episodic interference between the magnetic field of anti thief devices in stores (Electronic Article Surveillance, EAS) and pacemaker function have been reported, but no systematic in vivo study. 20 implanted pacemakers from ten different companies, 1 VVIR, 1 VDD and 18 DDD, were tested with two different EAS systems. #1 uses a 7.5 and 5 kHz field of 670 microTesla and #2 a 72.3 Hz magnetic field, of 1.10 microTesla. Under continuous ECG monitoring, patients had to walk through, and then stay between the doors while moving, and finally to lay against each wall. This was done with their usual pacemaker setting, and then set at their highest sensitivity in the unipolar atrial and ventricular mode. No abnormal PM behavior was observed with standard settings (V sensitivity 1.4 to 5 mV, A sensitivity 0.25 to 1 mV, bipolar (14) or unipolar (6). When programmed at the highest sensitivity, the magnetic field was detected by 5 models, but only with ventricular sensing set at less than 1.2 mV. moreover this only occurred in #2 EAS and not in #1. This resulted in short inhibitions < 1.2 s, and in one safety zone pacing. All occurred in devices conceived before 1993 (6/14) and none after (0/6). EAS devices should not inhibit implanted PM with standard settings, especially in recent models. Ventricular sensitivity should not be programmed in the unipolar mode at 1.2 mV or less.