pacemaker and surgery

1. All pacemaker patients should be having pacemaker checks at least annually, so there should not be
any need to arrange any additional checks pre-operatively. Sometimes patients are having more
frequent checks because of closer scrutiny of the pacemaker battery as it approaches end of service,
or some slowly developing component failure. Again, arranging additional checks pre-operatively out
with this programme should not be necessary.
Nothing that you do intra-operatively - at least nothing I can think of - will alter the pacemaker
programming, so if there have been no pre-operative programming changes and no observed
problems with the function of the pacemaker during the operation, post-operative checks should
not be needed.
It is important to identify ‘pacemaker dependent’ patients pre-operatively if diathermy is likely to be
used. My understanding is that this already happens.
Intraoperative considerations are as follows:
1) The likelihood of electrical interference with the pacemaker is very low, which is becoming
more evident over the years. Monopolar diathermy, where the electrical circuit includes an
extensive route through the patient’s body, has historically been the main concern. In theory
- and I’m sure there have been some cases in practice - it could cause a pacemaker to stop
working which would be potentially fatal in a pacemaker dependent patient. Modern bipolar
diathermy, where the electrical circuit is completed by very local passage of the current
through the tissues between two poles which are both close together on the tip of the
diathermy probe, is very unlikely indeed to cause a pacemaker to stop working.
2) There should be intraoperative ECG rhythm monitoring, but this is standard anyway in
anesthetised patients.
3) Where there is likely to be use of diathermy within 50cm of the heart - so any thoracic,
abdominal or pelvic surgery really - in a pacemaker dependent patient, then it would be
prudent to reprogram the pacemaker pre-operatively to an operation mode that won’t be
affected, and then re-re-program afterwards.
4) Where there is likely to be use of diathermy within 50cm of the heart in a patient with an
implantable cardioverter defibrillator (ICD), then it would be prudent to reprogram the ICD
immediately pre-operatively to an operation mode that won’t deliver shocks, and then re-re-
program immediately afterwards. In such patients the anesthetist should ensure that
external defibrillator pads are connected to the patient and there is an external defibrillator
to hand. If the surgery is such that access to the patient’s chest for closed chest compression
in the event of a cardiac arrest is impossible - which would mostly apply in thoracic surgery -
then the external defibrillator should be CONNECTED to the patient via the external
defibrillator pads.
5) In an emergency where a patient with an ICD undergoes an operation that involves
diathermy and where it has not been possible to switch off the defibrillator function pre-
operatively, a magnet should be available to be applied to the ICD during the period
diathermy is in use to temporarily switch off the defibrillator function.
6) If there is any suggestion on ECG monitoring that diathermy is adversely affecting
pacemaker or ICD function then either stop using it or continue using very short (2 second
maximum) bursts. Call for cardiology technical assistance.