Technical Services
15900 Valley View Court
Sylmar, CA 91342-3577
800 722 3774
Effects of Electric Motors on St. Jude Medical
Implantable Cardiac Rhythm Devices
Background
An electric motor is a type of machine that converts electrical energy into mechanical energy.
Electric motors operate through interacting magnetic fields and current-carrying conductors to
generate force. The reverse process, producing electrical energy from mechanical energy, is
accomplished by an alternator, generator, or dynamo. Electric motors may be powered by
direct current (e.g., a battery powered portable device or motor vehicle), or by alternating
current from a central electrical distribution grid.
Potential Effects
At this time we have no reports of large-scale electrical motors or portable generators affecting
our pacemakers or implantable cardioverter defibrillators (ICDs). However, this does not mean
there is a total absence of effects related to electric motors. Extraneous radiated noise from largescale electrical motors will not damage or reprogram a pacemaker or ICD. If large-scale electrical
motors do affect a pacemaker or ICD, inhibition, reversion to asynchronous pacing, or
inappropriate therapy may potentially occur. Some patients can tolerate reversion to
asynchronous pacing or some inhibition of their pacemaker or ICD. Any problems caused by
radiated interference will end when the electrical interference ends or the patient leaves the
immediate area.
A summary of potential effects is provided in the table below and is based on device testing at
St. Jude Medical, clinical experience and/or a review of the scientific literature.
Potential Effect
Asynchronous pacing
Inhibition of pacing or ATP/HV therapy
Inappropriate therapy
Estimated Frequency
Pacemakers
ICDs
Rare
N/A
Rare
Rare
N/A
Rare
Recommendations
The risk of working with electrical motors and portable generators may be reduced to an
acceptable level by observing proper techniques. Working on the motors with the power “OFF”
will avoid electrical interference.
Large scale motors seen in the industrial environment may have a greater likelihood of
interference. In power generating plants large motors are typically grounded and shielded which
minimizes the radiation of electrical noise. If documentation is needed for a patient’s work
environment, the physician can prescribe a Holter monitor, which records an ECG in the work
environment. The physician can also program the pacemaker or ICD to bipolar modes of
operation and reduce the sensitivity levels. These clinical suggestions can mitigate the potential
effects of EMI.
If you have any questions on this topic, please contact St. Jude Medical Technical Services at
800-722-3774.
Rev 11/10