Cardiac implantable electronic devices (CIEDs)

Learning objectives

Preoperative assessment and precautions for patients with a CIED
Intraoperative and postoperative management of patients with a CIED

Definition

Cardiac implantable electronic device (CIED) refers to any permanently implantable cardiac pacemaker or any implantable cardioverter–defibrillator (ICD), as well as any cardiac resynchronization therapy device

Possible perioperative adverse events

Device function	Damage to the device
	Inability to deliver pacing or shocks
	Lead-tissue interface damage
	Changes in pacing behavior
	Electrical reset to the backup pacing mode
	Inappropriate ICD therapies
Clinical	Hypotension
	Tachyarrhythmia and bradyarrhythmia
	Myocardial tissue damage
	Myocardial ischemia and infarction

Magnet use

Application of a magnet to a modern pacemaker produces an asynchronous mode of pacing to protect a patient from the effects of electromagnetic interference
A magnet can be secured over the pulse generator of an ICD to suspend the arrhythmia detection function and prevent discharge. Subsequent removal of the magnet promptly reactivates the ICD

Management

Preoperative
- Determine whether the patient has a CIED
- Determine the CIED type, manufacturer, and primary indication for placement
- Determine whether the patient is pacing-dependent
- Determine the CIED’s current settings and that it is functioning properly by interrogating the cardiac implantable electronic device or obtaining the most recent interrogation report
- Determine possible sources of electromagnetic interference:
  - Electrosurgery (monopolar > bipolar)
  - Evoked potential monitors
  - Nerve stimulators (twitch monitors)
  - Fasciculations
  - Shivering
  - Large tidal volumes
  - External defibrillation
  - Magnetic resonance imaging
  - Radiofrequency ablation or lesioning
  - Extracorporeal shock wave lithotripsy
  - Electroconvulsive therapy
- Determine precautions:

Intraoperative

Continuously monitor and display the electrocardiogram and SpO2
Perform continuous peripheral pulse monitoring for all patients
If unanticipated CIED interactions occur, temporarily suspend the procedure until the source of interference can be identified and eliminated or managed
Interference source management:

Interference source management:

Electrosurgery	Position the electrode so that the current does not pass through or near the CIED generator and leads
	Avoid proximity of the electrical current to the generator or leads
	When possible, use bipolar electrosurgery instead of monopolar
	When monopolar electrosurgery is necessary, use intermittent and irregular bursts at the lowest feasible energy levels
	Use an ultrasonic (harmonic) scalpel
	If monopolar electrosurgery is planned superior to the umbilicus, ensure that the pacing function is altered to an asynchronous pacing mode in pacing-dependent patients and suspend an ICD’s antitachycardia function, if present. Ensure that the patient is in a monitored environment
Radiofrequency ablation	Keep the radiofrequency current path (electrode tip to current return pad) as far away from the generator and leads as possible
	If radiofrequency ablation is planned superior to the umbilicus, ensure that the pacing function is altered to an asynchronous pacing mode in pacing-dependent patients and suspend an ICD’s antitachycardia function, if present. Ensure that the patient is in a monitored environment
Lithotripsy	Avoid focus of the lithotripsy beam near the generator
Magnetic Resonance Imaging (MRI)	Move the patient outside of the immediate MRI area
	Interrogate the CIED before the MRI scan
	Suspend the antitachycardia function of an ICD before the MRI scan
	Alter the pacing function to an asynchronous pacing mode in pacing-dependent patients before the MRI scan
	Ensure that someone capable of programming the CIED remains in attendance for the duration of the MRI scan
	Ensure that someone capable of performing advanced life support remains in attendance for the duration of the MRI scan
	Reinterrogate the CIED and restore its permanent settings after the MRI is completed
Radiofrequency identification devices	Avoid the use of these devices in close proximity to the CIED
	Monitor for signs of electromagnetic interference and be prepared to stop using the radiofrequency identification device if interference occurs
Electroconvulsive Therapy	Alter the pacing function to an asynchronous pacing mode in pacing-dependent patients
	Suspend an IDC’s antitachycardia function, if present
	Monitor for and be prepared to manage postconvulsive sinus tachycardia
	Monitor for and treat ventricular arrhythmias that may occur secondary to the hemodynamic effects of electroconvulsive therapy