RT-97
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Unusual pro-arrhythmic effects
in implantable cardiac pacemakers induced by mobile phones interference
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GianEnrico Antonioli, Gabriele
Guardigli, Anna Holzl, Tiziano Toselli, Gian Franco Percoco, Roberto Audoglio*.
Division of Cardiology, Arcispedale S. Anna, Ferrara, *SRA, Pavia, Italy
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Abstract
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During follow-up 142 patients were screened in order
to assess potential interference with two common transmission protocols used by cellular
phones: TACS and GSM. The screening included 27 models of pacemaker from 9 manufacturers.
All tests were performed under continuous ECG monitoring, programming the pacemaker at its
highest sensitivity and positioning phone antenna over the case. Phone antenna was than
driven away in order to measure the maximum interfering distance. This distance never
exceeded 11 cm in all tests.
Only some pacemaker had shown a reaction to interferences generated by phones. TACS
protocol was interfering in 16 patients (4 pacemaker models) and for a short period (<
3 s), at ringing and during switch-on or -off operation. GSM protocol affected 37 patients
(9 pacemaker models). Consequences of interference were: intermittent inhibition of
ventricular channel (2-3 s), constant inhibition of atrial channel, ventricular rate
tracking at upper limit, asynchronous pacing. In all patients, the anomalous behavior
reverted to normal condition when the phone was switched off. In 7 patients (4 pacemaker
models) the behavior was more complex, the induced high rate was arrhythmic and some time
anticipated by a long period (> 3 s) of total inhibition; in few cases
atrio-ventricular delay was shorter than the programmed value. Moreover interferences
induced tachycardia did not ended when phone was switched off; in 5 patients it was
necessary to use a magnet to stop the anomalous rate, in the last 2 patients it was
necessary to reprogram the device.
Conclusion. Cellular phones may be potentially dangerous for
pacemaker patients only when carried in a pocket closed to the pacemaker implant site.
TACS phones are substantially safe for all patient when GSM may interfere in a more
serious manner with some models of pacemaker. Four models do not automatically revert to
the programmed condition when phone transmission switch-off, but need some kind of
reprogramming, patients with those models implanted should avoid use of mobile phones.
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Key Words
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Pacemakers
cellular phones, electromagnetic interference, TACS technology, GSM technology,
proarrhythmic effects, OA
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