Management of Existing Pacemakers and Implantable Cardioverter-Defibrillators

Raja Selvaraj
Cardiac Electrophysiologist
Professor of Cardiology
JIPMER

Introduction

CIED (Cardiac Implantable Electronic Device)

• Pacemaker
• Defibrillator (ICD)
• Resynchronization therapy devices (CRT-P / CRT-D)

Pacemaker

CRT

ICD

Functions of CIEDs

Sensing

Pacing

Defibrillation

Cardiac Resynchronization

NASPE / BPEG Code

Electromagnetic interference

Potential disruption of operation when in vicinity of a source of electromagnetic field

Sources in OR

• Electro cautery
• Extracorporeal shock wave lithotripsy
• External defibrillation
• Evoked potentials
• Nerve stimulators
• Radiofrequency ablation

What does sensed activity do ?

• Can inhibit pacing
• Can trigger pacing
• Can result in arrhythmia detection
• EMI can also alter device function / damage device

Management of patient with CIED

• Pre operative planning
• Intra operative management
• Post operative management

Preoperative planning

• Evaluation
• Cardiologist evaluation ?
• Device interrogation ?
• Anticipated EMI - Site and type of surgery

Evaluation

• Type of device
• Underlying rhythm
• Underlying heart disease
• Pacing dependent ?
• Needs reprogramming / magnet application ?

Device Interrogation

• If not done recently
• AICD and CRT - 6 months
• Pacemaker - 12 months
• Otherwise review records

Anticipated EMI

• Use of possible EMI sources
• Site of surgery

Above vs below umbilicus

Intraoperative management

• Reduce EMI
• Alter device function to reduce risk from EMI
• Monitor rhythm for bradycardia
• Monitor for tachyarrhythmias and be prepared to treat

Reducing EMI

• Dispersive electrode placement
• Cautery modifications

Cautery modifications

• Use of bipolar cautery
• Planned placement of dispersive electrode
• Short bursts

Protocolized dispersive electrode

Monitoring of rhythm

• ECG may be obscured by noise
• Pulse oximeter waveforms
• Arterial pressure when available
• Remember that heart rate may be fixed and not usable for hemodynamic monitoring

Alter device function - Magnet or reprogramming

When is it needed

• Supra-umbilical surgery
• Monopolar cautery
• Pacing dependent patient or
• Patient with ICD

What does magnet application do ?

• Converts pacing to asynchronous mode in pacemakers
• Changes rate to "magnet rate"
• Disables tachyarrhythmia therapies in ICD

Advantages of magnet

• More accessible
• Convenient
• Needs no training
• Quick to reverse
• Convenient in emergency setting

Disadvantages of magnet

• Asynchronous pacing not always desirable - may trigger R-on-T
• Rapid rate may not be desirable
• Does not convert AICD to asynchronous pacing
• Difficulty in obtaining and confirming response from device
• Difficult in procedures where patient is not supine

Reprogramming

• Pacemakers - Reprogram to asynchronous mode when pacing dependent and EMI anticipated, turn off rate adaptive pacing
• ICD - Program tachyarrhythmia therapies off when EMI anticipated

Management of ventricular arrhythmia

• Patient with ICD turned off needs to be in a monitored setting
• Remove magnet or restore ATP therapies for ICD
• External defibrillation / cardioversion
• Antero posterior paddle position

Summary

• More patients in OR are going to have a CIED
• Anaesthetist should have some knowledge of CIEDs
• However, always preferable to involve a cardiologist / heart rhythm specialist
• Evaluation and reprogramming as needed is preferable to routine magnet placement