Cardiac Implantable Electronic Devices:
Pacers, ICDs, & CRT Devices

Updated January 27, 2015
Author: APSF Newsletter 2013, Multiple Sources

Description: Management of Pacers, (A)ICDs, and Bi-Ventricular Pacers in the peri-Op setting

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Pacemaker Codes & Nomenclature

Pacers and ICD devices use a Five Letter Code: first 3 letters most important

  1. First Letter: Chamber Paced
    A= Atrium
    V= Ventricle
    D= Dual (A+V)
  2. 2nd Letter: Chamber Sensed
    A= Atrium
    V= Ventricle
    D= Dual (A+V)
    O= None
  3. 3rd Letter: Response after Sensing:
    I = Pacing Inhibited
    T= Pacing Triggered
    D= Dual (I+T)
    O= None
  4. 4th Letter: Programmability
    P = Rate & Output
    M = Multiprogramable
    C = Communicating
    R = Rate adaptive
    O = None
  5. 5th Letter: Arrhythmia Control
    P = pacing
    S= shock
    D= Dual (P+S)
    O = None


VVI = Ventricle paced, ventricle sensed; pacing inhibited if beat sensed.

DDD = Atrium & ventricle can both be paced; atrium & ventricle both sensed; 
           pacing triggered in each chamber if beat not sensed


"Cardiovascular Implantable Electronic Devices (CIED)" ... a term that encompasses: 

    1. pacemakers for bradyarrhythmia treatment, 
    2. implantable cardioverter defibrillators (ICDs) for tachyarrhythmia management, and
    3. cardiac resynchronization therapy (CRT devices) (aka, Biventricular Pacer-ICD) for systolic dysfunction with conduction delays.

Peri-Operative Management requires that you know which type of device is implanted in your patient. It is also very helpful to have the Manufacturer of the device.

How to Determine Which Type of Device your Patient has:




(Apply to all implantable arrhythmia control devices)



B. ICDs, including CRT devices



A. Is RE-PROGRAMMING or DE-ACTIVATION of the device necessary? 
        If so, how do I do it?

To answer this question, you must know the TYPE OF DEVICE, and WHO MADE IT

a. What TYPE of Device is in my patient?

    1. Pacemaker ONLY. These patients can often be managed without re-programming or deactivation.
    2. Defibrillator/Pacer Combination. These patients usually require temporary re-programming or deactivation.

    Reprogramming is probably needed for:
     a. Pacer-dependent patient that cannot be managed with short cautery bursts
     b. Chest, shoulder, breast or abdomen case, where pacer site is in the surgical field
     c. Pt. who has pacer for obstructive or dilated cardiomyopathy
     d. Pt. w/ Defibrillator (ICD)

b. How do I DETERMINE what type of device is is my patient, and who is the manufacturer?

See Determining the Type of Device, above

B. I need to talk to somebody about this.

As of January 2015, MMC Cardiology has 5 EP Coordinators available to answer device-related questions prior to surgery. EP Coordinator phone is 885-9905. The EP Coordinator will help you determine if the patient is pacer-dependent based on records of the most recent interrogation. If pacer dependent, the device rep must be contacted for re-programming prior to the procedure.

Other questions, please contact:
   Paul Lennon, MD (Anesthesiology) pager 741-3630
   Joel Cutler, MD (Cardiology) phone 774-2642

Local Cardiology Practices (available 24/7):
   Maine Cardiology Associates (Charles Carpenter, Joel Cutler): 774-2642
   Cardiovascular Consultants (Andrew Corsello, John Love): 878-5051 or 885-9905
   Pediatric Cardiology Associates  (Michael Epstein) 773-2723

Other contact info:

800-227-3422 – Boston Scientific (formerly Guidant)
800-633-8766 – Medtronic
800-547-0394 - Biotronik
800-352-6466 - Ela
800-722-3774- St. Jude

the above numbers can be contacted 24/7 to obtain:

For Specific Information about pacemaker dependence or current settings, this number can also be used to contact a local device representative to help obtain more information.


  1. Roger VL, Go AS, Lloyd-Jones DM, et al. American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2011 update: a report from the American Heart Association. Circulation 2011;123:e18-e209.
  2. Moss AJ, Zareba W, Hall WJ, et al. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002;346:877-83.
  3. Cleland JG, Daubert JC, Erdmann E, Freemantle N, Gras D, Kappenberger L, Tavazzi L; Cardiac-Heart Failure (CARE-HF) Study Investigators. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005;352:1539-49.
  4. Crossley GH, Poole JE, Rozner MA, et al. The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus Statement on the perioperative management of patients with implantable defibrillators, pacemakers and arrhythmia monitors: facilities and patient management. This document was developed as a joint project with the American Society of Anesthesiologists (ASA), and in collaboration with the American Heart Association (AHA), and the Society of Thoracic Surgeons (STS). Heart Rhythm 2011;8:1114-54.
  5. Ho JK, Mahajan A. Cardiac resynchronization therapy for treatment of heart failure. Anesth Analg 2010;111:1353-61.
  6. Belott PH, Sands S, Warren J. Resetting of DDD pacemakers due to EMI. Pacing Clin Electrophysiol 1984;7:169-72.
  7. Godin JF, Petitot JC. STIMAREC report. Pacemaker failures due to electrocautery and external electric shock. Pacing Clin Electrophysiol 1989;12:1011.
  8. Mangar D, Atlas GM, Kane PB. Electrocautery-induced pacemaker malfunction during surgery. Br J Anaesth 1991;38:616-18.
  9. Lee D, Sharp VJ, Konety BR. Use of bipolar power source for transurethral resection of bladder tumor in patient with implanted pacemaker. Urology 2005;66:194.
  10. Casavant D, Haffajee C, Stevens S, Pacetti P. Aborted implantable cardioverter defibrillator shock during facial electrosurgery. Pacing Clin Electrophysiol 1998;21:1325-6.
  11. Van Hemel NM, Hamerlijnck RP, Pronk KJ, et al. Upper limit ventricular stimulation in respiratory rate responsive pacing due to electrocautery. PACE 1989;12:1720-23.
  12. Wong DT, Middleton W. Electrocautery-induced tachycardia in rate-adaptive pacemaker. Anesthesiology 2001;94:710-11.
  13. Furman S, Fisher JD. Endless loop tachycardia in an AV universal [DDD] pacemaker. Pacing Clin Electrophysiol 1982;5:486-9.
  14. Katzenberg CA, Marcus FI, Heusinkveld RS, Mammana RB. Pacemaker failure due to radiation therapy. Pacing Clin Electrophysiol 1982;5:156-9.
  15. Rozner M. Pacemaker misinformation in the perioperative period: programming around the problem [comment]. Anesth Analg 2004;99:1582-4.