9.3 Permanent pacemaker

Question 1

What are your key preoperative concerns when anaesthetising patients with PPMs?

Answer 1

Patient Factors

Pacemaker Factors

Surgical Factors

Question 2

Patient factors

Answer 2

• Indication for pacemaker
• Comorbid cardiac disease
• Underlying cardiac function
• Patients’ long-term use of anticoagulants (e.g. warfarin)

Question 3

Pacemaker factors

Answer 3

• Age and type of pacemaker or ICD,
  manufacturer,
  device,
  serial number
• Date pacemaker was last checked
• Details provided with the registration card or ‘PPM passport’

Question 4

Surgical factors

Answer 4

• Use of diathermy
• Surgical site proximity to the pacemaker

Question 5

What are the different types of PPM?

Answer 5

NAPSE/BPEG revised classification of pacemakers
(North American Society of Pacing and Electrophysiology/
British Pacing and Electrophysiology Group)

I
(chamber paced)

II
(chamber paced)

III
(response to sensing)

IV
(rate modulation)

V
(multisite pacing)

I+II+V
0 A V D

III
0
Triggered
Inhibited
Dual

IV
0 None
R - rate modulation

Question 6

How does the ‘rate modulation function?

Answer 6

An accelerometer or other means of measuring physical activity
is incorporated into the pacemaker,
usually increasing the paced rate to match physiological demand.

Question 7

If surgical diathermy is required intra-operatively, what are the risks

how can risk of pacemaker malfunction be minimised? (MHRA guidelines)

Answer 7

The use of surgical diathermy
can give rise to electrical interference,
and this can present additional risks
when used in patients with pacemakers.

Also, the energy induced into the heart lead system causes tissue heating.

Question 8

How can risk of pacemaker malfunction be minimised? (MHRA guidelines)

Answer 8

Preoperative
1. * Check correct functioning of the pacemaker.
2. * Programme parameters to avoid inappropriate inhibition.

Intraoperative

1. Wherever possible, avoid surgical diathermy in these patients.
2. But if it is deemed necessary, bipolar use is safer than monopolar diathermy.
3. • Monopolar, where necessary, should be used in short bursts
     at as low an energy as possible.
4. • Return plate should be placed as far away from the PPM as possible.
5. • Cables from diathermy equipment should be kept well away from PPM.
6. • In patients where the ICD is deactivated and where access to the anterior
     chest wall will interfere with surgery due to sterility,
     connect external defibrillator using remote pads.

Postoperative
Confirm device functionality on completion of surgery.

Question 9

How would your management change if the patient had an implantable cardiac defibrillator
(ICD)?

Answer 9

PPMs and ICDs have a magnetic switch that will respond to a magnet when
positioned over the device.

Elective procedures
The ICD is programmed to ‘monitor only’ mode by the cardiac physiologist
to prevent unnecessary shock in the event of accidental sensing of electrical interference.

External pads placed on the patient with external defibrillator ready to attach if required

Emergency procedure
Consider positioning a clinical magnet over the implant (done for whole
duration of surgery) to inhibit inappropriate shock delivery (if the device has
been programmed to respond this way). Any tachyarrhythmias during this
time warrant use of external defibrillation equipment.

Postoperatively, the patient should be managed on a high-dependency or
coronary care unit until the ICD has been checked and reactivated.

Question 10

Magnet + PPM

Answer 10

In patients with pacemakers, securing a magnet over the pacemaker implant
site will not necessarily guarantee asynchronous (non-sensing) pacing.
Magnet response may vary between manufacturers’ models and according
to particular programmed settings.