A patient with pacemaker presents a complex challenge to the attending anaesthesiologist. The mode of management will be according to the type of pacemaker implanted. This presentation discusses in brief the peri-operative consideration in a patient with pacemaker.

1. ANAESTHESIA FOR PATIENT
WITH PACEMAKER
DR HASSAN

2. OVERVIEW:-
1958: 1st Battery operated pacing devices.
•1980: Implantable Cardioverter
defibrillator (ICDs).
•Today: > 3,000 pacemaker models, produced
by 26 companies.
•USA data: > 250,000 adults & children
are undergoing Cardiac Rhythm
Management Device (CRMD) implantation
annually.(Global ~ 5 million)

3. WHAT IS A PACEMAKER?
• A PACEMAKER (OR ARTIFICIAL
PACEMAKER) IS A MEDICAL DEVICE
WHICH GENERATES ELECTRICAL
IMPULSES AND DELIVERS BY ELECTRODES
CONTRACTING THE HEART MUSCLES, TO
REGULATE THE BEATING OF THE HEART.

4. PARTS OF PACEMAKER
1. Pulse Generator: power source or battery.
(Zinc,Lithium Iodide)
2. Leads Or Wire: deliver electrical impulse.
3. Cathode: (-) electrode.
4. Anode: (+) electrode.

5. TYPES
1. TEMPORARY PACEMAKERS.
2. IMPLANTABLE CARDIOVERTER
DEFIBRILLATOR (ICDS).
3. PERMENANT PACEMAKERS.

6. TEMPORARY PACEMAKERS
• External, battery-powered, pulse generators
with exteriorized electrodes produce electrical
cardiac stimulation to treat a bradyarrhythmia
or tachyarrhythmia until it resolves or until
long-term therapy can be initiated.
• Used for less than three days.

7. -TRANSVENOUS -TRANSCUTANEOUS -EPICARDIAL
1. Transvenous pacing (Invasive)
2. Epicardial pacing (Invasive)
3. Transcutaneous pacing (Non Invasive)
4. Esophageal

8. IMPLANTABLE CARDIOVERTER
DEFIBRILLATOR (ICD)
• Specialized device designed for
tachyarrhythmia detection and therapy.
• Functions:-
1. Antitachycardia and antibradycardia pacing,
2. Synchronized (Cardioversion) shock.
3. Non synchronized (Defibrillation) shock.
4. Telemetry.
5. Diagnostics.

9. • INDICATION:-
• initial therapy in survivors of cardiac
arrest due to VF/VT.
• Syncope with hemodynamically unstable
sustained VT/VF.

10. PERMANENT PACEMAKER
• Implantable pulse generators with endocardial
or myocardial electrodes for long- term or
permanent use.

11. PERMANENT PACEMAKER
INDICATIONS:-
1. Symptomatic diseases of impulse formation (SA
Node Disease).
2. Symptomatic diseases of impulse conduction (AV
Node Disease).
3. Hypertrophic Obstructive Cardiomyopathy
(HOCM).
4. Dilated Cardiomyopathy (DCM).
5. Long QTSyndrome. Bryce et al, Ann Intern Med. 2001; 134:1130-41.

12. GENERIC CODE FOR PACEMAKER
NASPE/BPEG (North American Society Of
Pacing And Electrophysiology/ British Pacing
And Electrophysiology Group) Alliance

13. IMPORTANT TERMS REGARDING
PACEMAKERS.
1. Pacing
2. Sensing
3. Pacing Threshold
4. Capture
5. Rate Response
6. Triggered Pacing
7. Inhibition Of Output
8. Pacing Modes

14. 1. Pacing:-regular output of electrical current,
for the purpose of depolarizing the cardiac
tissue in the immediate vicinity of the lead,
with resulting propagation of a wave of
depolarization throughout that chamber.
2. Sensing:- response of a pacemaker to
intrinsic heartbeats.

15. 3. Pacing Threshold:-The threshold is the
minimum amount of energy the pacemaker
sends down the lead to initiate a heart beat.
4. Capture:- Cardiac depolarization and
resultant contraction (atrial or ventricular) -
Caused by pacemaker stimulus.
5. Rate response:- it have various sensors that
will active while patient during activities and
adjust the rate .

16. 6. Triggered pacing:- Dual chamber
pacemakers can be programmed to sense
activity in one chamber (usually the atrium)
and deliver a pacing stimulus in the other
chamber (usually the ventricle) after a certain
time delay.
7. Inhibition of Output:-pacemaker can be
programmed to inhibit pacing if it senses
intrinsic activity, or it can be programmed to
ignore intrinsic activity and deliver a pacing
stimulus anyway.

17. MODES OF PACING
1. Asynchronous Pacing.( eg. AOO,VOO,DOO)
2. Single Chamber Demand Pacing.
(eg. AAI,VVI)
3. Dual Chamber AV Sequential Demand
Pacing.(eg. DDD 70 with AV interval 200msec)

18. PROGRAMMABLE PACEMAKER
• Recent generation pacemakers provide flexibility
to device to patients changing metabolic needs.
• Capacity to noninvasively alter one of several
aspects of the function of a pacer.
• Sensors capable of detecting body movements,
changes in ventricular repolarisation, central
venous temprature, respiratory rate and depth
and right ventricular contractibility.

19. PROGRAMMABLE FACTORS:-
1. Pacing rate.
2. Pulse Duration.
3. Voltage output.
4. Refractory periods.
5. PR Interval.
6. Mode of pacing.
7. Hysteresis.

20. BIVENTRICULAR PACEMAKER/CRS
(CARDIAC RESYNCHRONISATION THERAPY)
• A pacemaker that paces both the septal and
lateral wall of left ventricle simultaneously.
• This resynchronizes a heart to contract in full
synchrony.
• Leads in right and left ventricle and right
atrium.

21. INDICATION:-
1. patients with dilated cardiomyopathy with
LVEF <35%
2. NYHA III/IV despite maximal medical
therapy(CHF)

22. Preoperative Evaluation
• Evaluation Of The Patient:-
• Underlying cardiovascular disease
responsible for pacemaker implantation.
• Any other associated illness e.g CAD, HTN,
DM etc.
• Severity of the cardiac disease.
• Current functional status.
• Medication status of the patient.

23. • PACEMAKER EVALUATION:-
• Type of pacemaker (fixed rate or demand rate).
• Conduct a focused physical examination (check for
scars and palpate for device).
• Half-life of the pacemaker battery.
• Effect of the Magnet Application on Pacemaker
Function.
• Time since implantation.
• Pacemaker rate at the time of
implantation.

24. • INVESTIGATIONS:-
• Routine investigation:- CBC,RFT
• Biochemistry serum electrolytes(s. K+, S.Na+)
• CXR, (continuity of leads)
• ECG, (Spike)

25. PREOPERATIVE PREPARATION
• Determine whether EMI is likely to occur
during the planned procedure.
• If interference is likely, reprogram CRMD and
suspend anti tachyarrhythmia function.
• Determine pacemaker baseline rate and
rhythm.
• Correct any underlying electrolyte abnormality
( if present)

26. CHOICE OFANAESTHESIA
• Technique may not influence directly but
physiological changes (acid-base, electrolytes)
& hemodynamic shifts (heart rate, rhythm,
hypertension, coronary ischemia) can change
CIED function & adversely effect patient
outcome.

27. ANAESTHETIC TECHNIQUE
• Narcotic and inhalational techniques can be
used successfully.
• In a patient with newly implanted pacemaker,
nitrous oxide is avoided – expansion of gas in
pacemaker pocket.
• Etomidate and ketamine should be avoided as
these cause myoclonic movements.
• Pacemaker function should be verified before
and after initiating mechanical ventilation as
Positive Pressure Ventilation can dislodge
pacemaker leads.

28. • Skeletal myopotentials, electroconvulsive
therapy, succinylcholine fasciculation,
myoclonic movements, or direct muscle
stimulation can inappropriately inhibit or
trigger stimulation, depending on the
programmed pacing modes.
• Care should be taken during insertion of guide
wire or central venous catheter as they are
arrhythmogenic and can dislodge pacemaker
leads.

29. MONITORING
• Based on the patient’s underlying disease and the
type of surgery.
• Continuous ECG monitoring (artifact filter
disabled).
• NIBP, ETCO2 and peripheral temperature
monitoring.
• Both electrical and mechanical evidence of the
heart function should be monitored by manual
palpation of the pulse, pulse oximetry, precordial
stethoscope and arterial line.

30. FACTORS AFFECTING PACING
THRESHOLDS
Increase
• 1-4 weeks after implantation
• Myocardial ischaemia/infaction
• Hypothermia, hypothyroidism
• Hyperkalaemia
• acidosis/alkalosis
• Antiarrythmics
• Severe hypoxia/hypoglycaemia
• Inhalation-local anaesthetics
Decrease
• Increased catecholamines
•Stress, anxiety
•Sympathomimetic drugs -
Anticholinergics
•Glucocorticoides
•Hyperthyroidism
•Hypermetabolic status

31. EFFECT OF EMI (Electromagnetic
Interference) ON PACEMAKER
1. Inhibition of pacing.
2. Asynchronous pacing.
3. Reset to back up mode.
4. Myocardial burn.(rare)
5. Ventricular fibrillation.(rare)

32. Measures To Decrease Possibility Of
Adverse Effects Due To EMI
• Bipolar cautery or ultrasonic (harmonic) scalpel
in place of a monopolar cautery, if possible.
• Unipolar cautery (grounding plate should be
placed close to the operative site and as far away as
possible from the site of pacemaker)
• Electrocautery should not be used within 15cm of
pacemaker.
• Pacemaker may be programmed to asynchronous
mode by a magnet or by a programmer.

33. • Provision of alternate temporary pacing.
• Drugs (isoproterenol and atropine) should
be available.
• Careful monitoring of pulse, pulse oximetry
and arterial pressure is necessary during
electrocautery, as ECG monitoring can also be
affected by interference.
• The device should always be rechecked after
operation.

34. MAGNET APPLICATION ON PACEMAKER
FUNCTION
• The magnet is placed over the pulse generator
to trigger the reed switch present in the pulse
generator resulting in a non-sensing
asynchronous mode with a fixed pacing rate
(magnet rate).
• It shuts down the demand function so that the
pacemaker stimulates asynchronous pacing.
Thus, it protects the pacemaker dependent
patient during EMI, such as diathermy or
electrocautery.

35. • The response varies with the model and the
manufacturer so advisable to consult the
manufacturer to know the magnet response
before use.
• Demonstrates remaining battery life and
sometimes pacing thresholds.
• Complications- ventricular asynchrony, altered
programming.

36. EMERGENCY DEFIBRILLATION OR
CARDIOVERSION
• In a patient with ICD and magnet-disabled
therapies, Before attempting emergency
defibrillation or cardioversion:-
-All sources of EMI should be terminated.
-Remove the magnet to reenable antitachycardia
therapies.
• Patient with ICD and antiarrhythmic therapies that
have been disabled by programming, consider re
enabling therapies through programming.
• If it fail to restore ICD function, proceed with
emergency external defibrillation or cardioversion.

37. • Follow ACLS guidelines for energy level and for
paddle placement.
• If possible, attempt to minimize the current flowing
through the pulse generator and lead system by
positioning the pads or paddles:-
-as far as possible from the pulse generator.
-perpendicular to the major axis of the CIED pulse
generator and leads to the extent possible by
placing them in an anterior-posterior location.

38. Specific Perioperative Considerations
 Transuretheral Resection of Prostate (TURP)
and Uterine Hysteroscopy.
 Electroconvulsive Therapy.
 Radiation.
 Nerve Stimulator Testing or Transcutaneous
Electronic Nerve Stimulator Unit. (TENS)
 Lithotripsy.
 Magnetic Resonance Imaging (MRI).

39. Postoperative Care
• Cardiac rate, rhythm monitoring continuously.
• Shivering and fasciculation should be avoided.
• Back-up pacing capability and cardioversion
defibrillation equipment should be immediately
available at all time.
• Interrogate CIED; consultation with a cardiologist
or pacemaker-ICD service may be necessary.
• Restore all antitachyarrhythmic therapies in ICDs
• Assure that all other settings of the CIED are
appropriate.

40. SUMMARY
• Adopting a multidisciplinary approach that
involves the surgeon, anesthetist, cardiologist and
industry employed allied health professional is
ideal for safe peri-operative CIED management .
• Decision-making process should be tailored to
individual patients and their needs, with the aim
of preventing haemodynamic embarrassment
consequent to CIED malfunction.
• Anaesthetic management should be planned
preoperatively according to patient’s medical
status.

41. • Monitoring and anesthesia technique with due
considerations to patients CVS status.
• Initiate invasive arterial pressure monitoring in
addition to standard monitoring.
• Avoid electrocautery use, If necessary consider
use of bipolar or harmonic scalpel.
• Be ready for alternate mode of pacemaker and
defibrillator if necessity arises.
• Rate responsive pacemakers should have rate
responsive mode disabled before surgery.
• Pacemaker should be rechecked after the
procedure.

42. THANK YOU