david daly alfred hospital monash university...pacemakers and internal cardiac defibrillators david...

Perioperative Care ofPacemakers and Internal Cardiac Defibrillators

David Daly

Alfred Hospital

Monash University

Mr Jones: Lap Chole 2200 hours

• Bloods gone off – best to operate tonight



• Fit as a Mallee Bull Doc….




• I see you have a pacemaker Mr Jones

Well…What Could Go Wrong?

• Oversensing

• Device reset

• Exit block

• Lead damage

• Tachyarrhythmias

• Etc

Electromagnetic Interference (EMI)

“Noise” sensed by the

device

Device should have

paced





• Is that what you call it Doc….?





• Is that what you call it Doc….?

• Do you have the little plastic card your cardiologist asked you to always carry, especially when you go to hospital?

Answer = YES

• You beauty

• Call device company and get some info

• Indication + level of patient dependency

• Device type

• ERI

• Magnet behavior

• Therapies activated

• General advice

Company Contact Numbers

• Medtronic/Vitatron: 1800 668 670

• Boston Scientific/Guidant/CPI: (02) 8063 8100

• Biotronik: (02) 9497 3700

• St Jude Medical/Ventritex: (02) 9936 1200

Manufacturer advice

• Avoid EMI• Use bipolar diathermy of harmonic scalpel• If monopolar diathermy:

– Avoid current pathway across CIED or device leads– Short bursts (<4 seconds)– Interval > 2 seconds between bursts– Use lowest current possible– Probably okay beneath umbilicus– Have a magnet available– Do you have a transcutaneous pacemaker just in case.

Answer = Yes I always take it to the pacemaker clinic when I get a checkup but why would I need it to get my gallbladder out? Its at my

grandson's house in Cooktown but he is on a Virgin flight to Mars.

• History

• Examination

• ECG

• CXR

CXR

• You should be able to identify the type of device in there

• Be a bit wary of old fractured leads that have been left in position

• You may be able to read manufacturer’s marks from a digital blowup of the can.

ECG

• If pacing best to assume things will get ugly if oversensing occurs

Perioperative Management of ICDs

Abbreviations

• ICD=Implantable cardioverter defibrillator

• CIED=Cardiovascular implantable electronic device

• EMI=Electromagnetic interference

• ECT=Electroconvulsive therapy• CRT-P=Cardiac

resynchronisation therapy pacemaker

• CRT-D=CRT defibrillator

Recognizing SystemsPacemakers

Dual Chamber Pacemaker

RV Lead at the Apex

RA Lead in Appendage

Recognizing SystemsICD or High Power

Right Atrial Lead

Approximate position outlined

Right Ventricular Lead

With RV and SVC coils

Recognizing SystemsCRT Low-Power

Right Atrial Lead

Left Ventricular Lead

Placed on the surface of the

LV via the Coronary Sinus


Recognizing SystemsCRT High-Power

Right Atrial Lead

Left Ventricular Lead

Placed on the surface of the

LV via the Coronary Sinus


Note the 2 high voltage defib

coils

Surface ECG leads

ICD Therapy

Brady and Anti-Tachy pacing (ATP)

• The ICD lead is designed to carry both high voltage and pacing therapies– Brady– ATP– Cardioversion– Defibrillation

• Typically about a 7F diameter lead

How do I know the device or the manufacturer by a simple CXR of device

22

What Does A Typical System Look Like?

23

Revised Standard of implant care

Tip lifted under fluoroSlight lift of lead tip from apex

24

PPM and ICD System

29

Today’s ICDs

What am I?

• PM

• PM rate responsive

• T-CRT-P

• T-ICD

• T-ICD-P

• T-CRT-D

35

Bipolar and Unipolar Pacing

• PPM & ICDs use either bipolar and unipolar leads for sensing intrinsic rhythm.

• If no underlying rhythm EMI can cause PPM inhibition.

• Magnet usages may be a problem in PPM if intrinsic conduction above magnet rate.

Sources of EMI Are Found Most Commonlyin Hospital Environments

• Sources of EMI that interfere with pacemaker operation include surgical/therapeutic equipment such as:– Electrocautery

– Transthoracic defibrillation

– Extracorporeal shock-wave lithotripsy

– Therapeutic radiation

– RF ablation

– TENS units

– MRI

ICD Magnet Interactions

• Medtronic Magnet Function– Suspends detection and therapy when held over the

device– It will not permanently change ANY device settings– Detections are active when magnet is removed– All setting back to normal when removed– No effect on pacing, pacing mode, rate, and interval

as programmed– May produce audible tones initially (~20s)

• Patient must be continuously monitored!

ICD Functions

• ICD functions come first – Sensing

– Detection

– Therapies

• ICD is a pacemaker too– Pacing

– Magnet application does not affect pacing function of an ICD

Different Manufacturers of ICD’s

• Medtronic

• Boston Scientific (Guidant)

• St. Jude (Telectronics,Ventritex)

• Biotronic

• ELA /Sorin

40

Magnet application causes asynchronous pacing at a designated “magnet” rate

Magnet over a pacemaker

Manufacturer Battery OK ERI

Medtronic 85 65

Boston Scientific (Guidant) 92 85

St Jude (Telectronics, Ventritex) 98.5 85.5

Biotronic 90 78

ELA 92 95

41

No Magnet - VVI

Magnet – VVI or DDD ?

Medtronic

• Magnet will suspend therapy detection when placed over the device

• It may make a solid tone

• It will not permanently change device settings

• Once magnet is removed the device therapy is activated again

Magnet Operation

• ICD– Magnet Suspends Detection and Therapy

• i.e. No sensing or treatment of arrhythmias

– No changes to the pacing programming

• Pacemaker – Magnet causes it to pace without sensing

– Paces VOO or DOO

ICD Perioperative Use of Magnet

• Why would you want to use a magnet with your ICD patient?

• What would you consider for a patient who is pacemaker dependent?

48

PPM Perioperative Use of Magnet

• Why would you use a magnet with your ICD patient?

– To disable therapy to prevent inappropriate shocks

• What would you consider for a patient who is pacemaker dependent?

– Magnet placement for asynchronous pacing.

Magnet Interactions

• Medtronic Pacemaker Magnet Function– Paces the patient without sensing (DOO, VOO)– Rate = 85 bpm*

• If 65 bpm – pacemaker may need replacement– No audible tones from pacemakers

• If you hear a tone the device is not a PM– Once magnet is removed the device returns to original

programming• Considerations for PPM dependent patients

– If any EMI is likely, use a magnet• Consideration if rate response is programmed on and

vibrations are possible– Use magnet or consider turning off rate response

* Some older devices are based off the programmed lower rate

Cardiac Rhythm Management Device Practice Advisory1

• Preoperative Evaluation

• Preoperative Preparation

• Intraoperative Management

• Postoperative Management

1 Practice Advisory for the Perioperative Management of Patients with Cardiac RhythmManagement Devices: Pacemakers and Implantable Cardioverter-Defibrillators(Approved by the ASA House of Delegates on October 27, 2004)

Preoperative Evaluation

• Establish whether the patient has a device– Pts have all been advised to carry ID card, (CXR) or

magnet use?

• Define the Type of Device – Physician & Manufacturer

• Determine Dependency on Device– Underlying Rhythm or not

• Determine Device Function– What therapies are programmed and why.


Preoperative Preparation

• Determine if EMI is likely to occur during procedure.

• Determine whether reprogramming necessary– Pacing function to asynchronous mode – Disabling rate responsive function for vibration.

• Consider suspending ICD therapy if present• Use of a bipolar diathermy. • Temporary pacing and defibrillation equipment

available for day of proceedure.


Intraoperative Management

• Monitor operation of the Device– Continuous Cardiac ECG monitoring– Monitor peripheral pulse (e.g., manual pulse palpation, pulse

oximeter, arterial line)– Defibrillation & Emergency equipment available at all times.

• Manage potential device dysfunction due to EMI– Electrocautery– Radio-frequency (RF) ablation– Lithotripsy– Vibration and magnets.


Intraoperative Management

• Manage potential device dysfunction due to EMI– Electrocautery

• Assure that the electrosurgical receiving plate is positioned so that the current pathway does not pass through or near the CRMD system.

• Avoid proximity of the cautery’s electrical field to the pulse generator or leads.• Use short, intermittent and irregular bursts at the lowest feasible energy levels.• Bipolar electrocautery system or ultrasonic (harmonic) scalpel in place of a monopolar

electrocautery system, if possible.

– Radio-frequency (RF) ablation• Avoid direct contact between the ablation catheter and the pulse generator and leads.• Keep the RF’s current path as far away from the pulse generator and lead system as possible.

– Lithotripsy Vibration• Avoid focusing the lithotripsy beam near the pulse generator. MDT recommends >18 cm away.

<5cm may damage device• If the lithotripsy system triggers on the R-wave, consider preoperative disabling of atrial pacing

• 1 Practice Advisory for the Perioperative Management of Patients with Cardiac Rhythm• Management Devices: Pacemakers and Implantable Cardioverter-Defibrillators• (Approved by the ASA House of Delegates on October 27, 2004)

Intraoperative Management (Cont.)

• Manage potential device dysfunction due to EMI (Cont.)– Magnetic Resonance Imaging

• MRI is generally contraindicated in patients with devices.

– Radiation Therapy• Radiation therapy can be safely performed in patients who have devices.

• Surgically relocate the device if the device will be in the field of radiation.

– Electroconvulsive Therapy• Consult with the ordering physician, the patient’s cardiologist, a device service, or the

device manufacturer


Intraoperative Management (Cont.)

• Emergency defibrillation or cardioversion– For the patient with an ICD and magnet-disabled therapies:

• Terminate all sources of EMI while magnet is removed.• Remove the magnet to re-enable antitachycardia therapies.• Observe the patient and the monitors for appropriate device therapy.• If fail to restore ICD function, proceed with emergency external defibrillation or

cardioversion.– For the patient with an ICD and programming-disabled therapies:

• Terminate all sources of EMI while magnet is removed (if applied)• Re-enable therapies through programming if the programmer is immediately

available• Observe the patient and the monitors for appropriate CRMD therapy• If fail to restore ICD function, proceed with emergency external defibrillation or

cardioversion– For external defibrillation:

• Position defibrillation/cardioversion pads or paddles as far as possible from the pulse generator and in an anterior-posterior location

• Use a clinically appropriate energy output


Postoperative Management

• Continuously monitor cardiac rate and rhythm and have back-up pacing and defibrillation equipment immediately available throughout the immediate postoperative period

• Interrogate and restore device function in the immediate postoperative period– Interrogate device; consultation with a cardiologist or pacemaker-

ICD service may be necessary

– Restore all anti-tachyarrhythmic therapies in ICDs

– Assure that all other settings of the device are appropriate


Fixed or Demand (now you’re in trouble!)

Output goes up in 10 mA increments and down in 5 mA increments

david daly alfred hospital monash university...pacemakers and internal cardiac defibrillators david...

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