[Effects of 50 to 60 Hz and of 20 to 50 kHz magnetic fields on the operation of implanted cardiac pacemakers].
The effect of 50 Hz and 60 Hz (frequencies of current distribution) and 20 kHz to 50 kHz (frequencies of induction cooktop) magnetic interference on implanted pacemakers have been assessed with the present generation of device technology. Sixty patients implanted in 1998 and 1999 with dual chamber pacemakers from 9 different manufacturers were monitored with telemetry while passing through, and standing between a system of two coils. They generated a 50 Hz or a 60 Hz magnetic field at 50 microT. Then, patients used a cooktop at different power. The recordings were made with the standard setting of "medically correct" sensing parameters chosen for the patients. Then pacemakers were reprogrammed to the unipolar mode, with the highest atrial (A) and ventricular (V) sensitivity that did not induce muscular inhibition while moving. Between each exposure (50 Hz, 60 Hz or 20 kHz to 50 kHz), the pacemaker programmation was controlled. At the end of the tests, pacemakers will be reprogrammed with the standard setting. The medical observer being blind to the existence or not of the magnetic field. No pacemaker was influenced by the vicinity of the magnetic field at medically correct settings. At unipolar high sensitivity, no inhibition nor reprogramming was observed. Transient reversion to interference mode was observed in 6 cases, 3 transient acceleration due to atrial detection of the interference, and one T wave detection by the ventricular lead. All were observed with the 60 Hz, and only 3 with the 50 Hz magnetic field. One device (Biotronik) shifted out of its special program (hysteresis research) during the tests with the induction cooktop, but it maintained its standard program, and the event could not be repeated despite further testing.


CONCLUSIONS
Actual pacemakers do not present any electromagnetic interference with 50 Hz and 60 Hz or induction cooktop frequency working. They are insensitive with medically correct settings. Unusual high sensitivity leads only to noise reversion mode, or transient ventricular tracking.
Frank
R
R
Institut de cardiologie, service de rythmologie, hôpital La Pitié-La Salpêtrière, 52-56, bd Vincent Auriol, 75013 Paris.
Souques
M
M
Himbert
C
C
Hidden-Lucet
F
F
Petitot
J C
JC
Fontaine
G
G
Lambrozo
J
J
Magne
I
I
Bailly
J M
JM
D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D004867:Equipment Design; D006801:Humans; D008991:Monitoring, Physiologic; D010138:Pacemaker, Artificial / Q000009:adverse effects; D011846:Radio Waves; D013686:Telemetry