BIOTRONIK ProMRI Estella SR Manual Tecnico página 6

Nerve and muscle stimulation
A device system consisting of a unipolar lead and an uncoated device may result in
undesirable pacing of the diaphragm in the case of an initial or permanent high setting
of the pulse amplitude.
• BIOTRONIK also provides coated devices.
Possible Technical Complications
Technical malfunctions
Technical device system malfunctions cannot entirely be excluded. Possible causes can
include the following:
• Lead dislocation
• Lead fracture
• Insulation defects
• Device component failures
• Battery depletion
Possible Electromagnetic Complications
Electromagnetic interference (EMI)
Any device can be sensitive to interference, for example, when external signals are
sensed as intrinsic rhythm or if measurements prevent rate adaptation.
• BIOTRONIK devices have been designed so that their susceptibility to EMI is
minimal.
• Due to the intensity and variety of EMI, there is no guarantee for safety. It is
generally assumed that EMI produces only minor symptoms in patients - if any.
• Depending on the pacing mode and the type of interference, sources of interference
may lead to pulse inhibition or triggering, an increase in the sensor-dependent
pacing rate or asynchronous pacing.
• Under unfavorable conditions, for example during diagnostic or therapeutic
procedures, interference sources may induce such a high level of energy into the
pacing system that the cardiac tissue surrounding the lead tip is damaged.
Device behavior in case of EMI
In the case of electromagnetic interference or undesired myopotentials, the device
switches to asynchronous pacing for the duration of the time that the interference rate
is exceeded.
en • English
Static magnetic fields
The reed switch in the pacemaker starts to close at a field strength of 1.5 mT.
Possible Risks
Contraindicated procedures
Due to possible damage to the patient or the device, the use of the following procedures
is contraindicated:
• Therapeutic ultrasound: damage to the patient via excess warming of body tissue
near the device system
• Transcutaneous electrical nerve stimulation
• Hyperbaric oxygen therapy
• Applied pressures higher than normal pressure
Risky therapeutic and diagnostic procedures
If electrical current from an external source is conducted through the body for
diagnostic or therapeutic purposes, then the device can be subjected to interference
and the patient be placed at risk.
Arrhythmia or ventricular fibrillation can be induced during diathermic procedures
such as electrocautery, HF ablation or HF surgery. For example, damaging heat can
result during lithotripsy. Influences on the device are not always immediately clear.
If risky procedures cannot be avoided, the following should be observed at all times:
• Electrically insulate the patient.
• Switch the pacemaker function to asynchronous modes if needed.
• Do not introduce energy near the device system.
• Additionally check the peripheral pulse of the patient.
• Monitor the patient during and after every intervention.
External defibrillation
The device is protected against the energy that is normally induced by external
defibrillation. Nevertheless, any implanted device may be damaged by external
defibrillation. Specifically, the current induced in the implanted leads may result in
necrotic tissue formation close to the electrode/tissue interface. As a result, sensing
properties and pacing thresholds may change.
• Place adhesive electrodes anterior-posterior or perpendicular to the axis formed
by the device to the heart at least 10 cm away from the device and from implanted
leads.
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