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Table of Contents
Year : 2020  |  Volume : 23  |  Issue : 4  |  Page : 493-495
Anesthetic consideration for patients with micra leadless pacemaker

Department of Anesthesiology, University of Minnesota, Minneapolis, MN, USA

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Date of Submission20-Dec-2019
Date of Decision07-Aug-2020
Date of Acceptance08-Aug-2020
Date of Web Publication19-Oct-2020


MICRA, miniaturized leadless single chamber pacemaker, is inserted directly into the right ventricular myocardium via transcatheter approach. We present a case of a 66-year-old patient with a Micra pacemaker scheduled for kidney-pancreas transplant. The patient is pacemaker dependent. The preoperative cardiology consult did not comment on the need of reprogramming. One hour prior to the surgery, the anesthesia team was unable to locate the pacemaker on the chest wall. The Medtronic hotline was called, and the caregivers learned that the particular pacemaker is buried within the ventricular wall and is not responsive to an external magnet. Thus, the case was delayed and a cardiac electrophysiology team was contacted to reprogram the pacemaker to VOO (fixed ventricular pacing) mode. We suggest that the pacemaker can pose perioperative challenges due to its novelty, paucity of report, and guidelines.


How to cite this article:
Karuppiah S, Prielipp R, Banik RK. Anesthetic consideration for patients with micra leadless pacemaker. Ann Card Anaesth 2020;23:493-5

How to cite this URL:
Karuppiah S, Prielipp R, Banik RK. Anesthetic consideration for patients with micra leadless pacemaker. Ann Card Anaesth [serial online] 2020 [cited 2021 Sep 25];23:493-5. Available from:

   Introduction Top

Anesthesia personnel are challenged with ever more common and complex implanted medical devices (”black boxes”). Lack of familiarity and experience can lead to device mismanagement or failure resulting in patient complications.[1] Approximately, 200,000 cardiac pacemakers are implanted every year in the United States alone.[2] Since the first pacemaker implantation in 1950s, the technology, sophistication, and complexity of these devices continue to advance. Leadless pacemakers have been approved for use in Europe since 2013 but the first leadless cardiac pacing system was approved for use in the United States in 2016.[3] Currently, two leadless pacing systems are available: The Micra transcatheter Pacing system (Micra TPS; Medtronic, Minneapolis, MN) and the Nano stim Leadless Cardiac Pacemaker (St. Jude Medical, Sylmar, California USA).[4] Both systems utilize advanced battery technology that facilitates leadless implantation, with the goal to reduce the significant potential morbidity associated with catheter-based delivery systems. However, these new pacemakers are not widely used and therefore anesthesiologists are less likely to be familiar with this technology. Supporting this hypothesis, we report a patient with a Micra TPS pacemaker undergoing a kidney transplant surgery, but the unique perioperative requirements associated with this pacemaker were recognized only minutes prior to the scheduled start of the case.

   Case Report Top

A 66-year-old man with a leadless Micra Transcatheter Pacemaker System was scheduled for kidney-pancreas transplant for end-stage renal disease secondary to long-term diabetes and hypertension. His significant past medical history included atrial fibrillation, diastolic heart dysfunction, and obstructive sleep apnea that required nightly continuous positive airway pressure. He previously underwent nephrolithotomy, vitrectomy of the left eye, atrioventricular nodal ablation and Micra pacemaker implantation for refractory atrial fibrillation with rapid ventricular rate response without complications.

The patient's preoperative workup included normal values for his laboratory tests of a complete blood count, comprehensive metabolic panel, and liver function test with the exception of an elevated creatinine, BUN, and urea. His electrocardiogram and echocardiogram prior to the surgery showed complete heart block with ventricular pacing, normal bi-ventricular function, grade II diastolic dysfunction, and no valvular abnormalities. Preoperative cardiac stress testing did not reveal any inducible ischemia.

As a routine preparation for transplant surgery, he was evaluated by the inpatient cardiology team several hours before the surgery. The cardiologist recommended no further evaluation or tests necessary for the planned transplant surgery. Moreover, there were no recommendations for any special precautions regarding the Micra pacemaker.

One hour prior to the surgery during preoperative evaluation, the anesthesia team was unable to locate the pacemaker on the chest wall. The Medtronic hotline (1-800-633-8766, toll-free within the United States) was called for insights of this pacemaker, and caregivers learned this particular pacemaker is buried within the ventricular wall. Moreover, this type of pacemaker is not responsive to an external magnet. Since the patient is pacemaker dependent, the case was delayed to allow cardiac electrophysiology team reprogram the pacemaker (to VOO mode). His transplant surgery was then completed without complications.

   Discussion Top

The Micra TPS pacemaker is 93% smaller than a conventional pacemaker and is directly implanted into the right ventricular myocardium.[5],[6] The pacemaker measures 2.6 × 0.7 cm and requires a 23-French introducer sheath which is placed via the transfemoral approach, but in selective patients, it has been successfully implanted via a transjugular approach.[7],[8] It has an estimated longevity of about 12 years.[8] Micra pacemaker is recommended for patients with symptomatic high-grade atrioventricular nodal block with or without atrial fibrillation, symptomatic bradycardia-tachycardia syndrome, and sick sinus syndrome. It has pacing modes such as VVIR, VVI, VOO, and OVO.[7],[8] It has 63% fewer complications than conventional pacemakers, including problems that are related to either the lead wires themselves, or the pacemaker pocket in the chest wall. Moreover, patient experiences no scar or deformity of the chest wall.[9] The most common device-related complications include device dislodgement (1.7%), cardiac perforation (1.3%), and elevated pacing thresholds requiring device repositioning (1.3%).[7],[9],[10]

Use of electrocautery in the intraoperative period can cause significant interference with these pacemakers as well as automated implantable cardiac defibrillators (AICD). Common problems include unintended pacemaker inhibition, inappropriate tracking or interpretation of electrical noise, damage at the lead-tissue interface, pulse generator damage, delivering inappropriate pacing or shocks, and the induction of an electrical reset mode.[11],[12] Sources of electromagnetic interference (EMI) in the perioperative period are the use of electrocautery, use of transcutaneous electrical nerve stimulation for postoperative pain, electroconvulsive therapy, radiation therapy, magnetic resonance imaging, and extracorporeal shockwave lithotripsy.[13],[14] The consensus statement from American society of anesthesiologist (ASA) and Heart rhythm society (HRS) recommends that focused preoperative evaluation should be done in patients with cardiovascular implantable electronic device, which includes defining the type and location of device, details of last device interrogation, manufacturer, model of the device, and dependency of the patient for antibradycardia pacing function and defibrillation.[15],[16]

ASA/HRS recommendations for pacemaker-dependent patients also include the use of the shortest feasible electrosurgical bursts. In addition, anesthesia professionals should have a magnet immediately available for procedures below the umbilicus and in nondependent patients, whereas they should actually place the magnet over device for procedures above the umbilicus or those that require extensive electrocautery.[15],[16] In AICD patients, recommendations are to use short electrosurgical burst and place magnet over the device to suspend tachyarrhythmia detection.[16] However, there is no mention of newer devices such as leadless pacemakers like Micra.

Medtronic Leadless Micra pacemaker technology is a promising long-term permanent cardiac pacing option for patients requiring only RV pacing [Figure 1].[17] However, because of its intracardiac location and absence of hall sensor, reprogramming cannot be achieved by clinicians at the bedside with placement of a magnet prior to or during surgery.[18] In the absence of guidelines from ASA and HRS, it is important for anesthesiologists to determine the risk of EMI prior to surgical procedures. If there is a concern for EMI, Medtronic recommends to consider a preoperative asynchronous programming and restore device parameters after the surgery. In urgent cases where preoperative reprogramming is not be possible, general procedures should be followed as outlined in [Table 1].[19]
Figure 1: Leadless pacemaker (MICRA) located in the right ventricle

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Table 1: Emergency pacemaker management absent reprogramming

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Financial support and sponsorship

This work was supported by the Department of Anesthesiology, University of Minnesota and Fairview Medical Center, United States.

Conflicts of interest

There are no conflicts of interest.

   References Top

Dhawan I, Tewari A, Sehgal S, Sinha AC. Medication errors in anesthesia: Unacceptable or unavoidable? Braz J Anesthesiol 2017;67:184-92.  Back to cited text no. 1
Permanent Leadless Cardiac Pacing-American College of Cardiology [Internet]. [Cited 2019 Oct 12]. Available from: cardiology/articles/2016/03/23/08/09/permanent-leadless-cardiac-pacing.  Back to cited text no. 2
Bhatia N, El-Chami M. Leadless pacemakers: A contemporary review. J Geriatr Cardiol 2018;15:249-53.  Back to cited text no. 3
El-Chami MF, Merchant FM, Leon AR. Leadless pacemakers. Am J Cardiol 2017;119:145-8.  Back to cited text no. 4
5. 2019 [cited 13 October 2019]. Available from:  Back to cited text no. 5
Williams E, Whiting J. Micra Trans catheter Pacing System Size Comparison, November 2014, Medtronic Data on File.  Back to cited text no. 6
Medtronic Micra MC1VR01 Clinician Manual. November 2014.  Back to cited text no. 7
Duray GZ, Ritter P, El-Chami M, Narasimhan C, Omar R, Tolosana JM, et al. Long-term performance of a trans catheter pacing system: 12-month results from the Micra Trans catheter Pacing Study. Heart Rhythm 2017;14:702-9.  Back to cited text no. 8
Reynolds DW, Duray GZ, Omar R, Soejima K, Neuzil P, Zhang S, et al. A Leadless intracardiac trans catheter pacing system. N Engl J Med 2016;374:533-41.  Back to cited text no. 9
Essandoh M. Perioperative management of the Micra leadless pacemaker. J Cardiothorac Vasc Anesth 2017;31:e97-8.  Back to cited text no. 10
Stone ME, Salter B, Fischer A. Perioperative management of patients with cardiac implantable electronic devices. Br J Anaesth 2011;107:i16-26.  Back to cited text no. 11
Misiri J, Kusumoto F, Goldschlager N. Electromagnetic interference and implanted cardiac devices: The medical environment (Part II). Clin Cardiol 2012;35:321-8.  Back to cited text no. 12
Thompson A, Mahajan A. Perioperative management of cardiovascular implantable electronic devices: What every anesthesiologist needs to know. Anesth Analg 2013;116:276-7.  Back to cited text no. 13
Madigan JD, Choudhri AF, Chen J, Spotnitz HM, Oz MC, Edwards N. Surgical management of the patient with an implanted cardiac device: Implications of electromagnetic interference. Ann Surg 1999;230:639.  Back to cited text no. 14
Practice advisory for the perioperative management of patients with cardiac implantable electronic devices: Pacemakers and implantable cardioverter-defibrillators: An updated report by the American society of anesthesiologists task force on perioperative management of patients with cardiac implantable electronic devices. Anesthesiology 2020;132:225-52.  Back to cited text no. 15
Crossley GH, Poole JE, Rozner MA, Asirvatham SJ, Cheng A, Chung MK, 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.  Back to cited text no. 16
Reynolds D, Duray GZ, Omar R, Soejima K, Neuzil P, Zhang S, et al. A Leadless Intracardiac Transcatheter Pacing System. N Engl J Med 2015;374:533-41.  Back to cited text no. 17
Gifford J, Saleem M. Evaluation of surgical electromagnetic interference in leadless pacemakers. Heart Rhythm Case Rep 2018;4:570-1.  Back to cited text no. 18
Ozeren M, Doǧan OV, Düzgün C, Yücel E. Use of an ultrasonic scalpel in the open-heart reoperation of a patient with pacemaker. Eur J Cardiothorac Surg 2002;21:761-2.  Back to cited text no. 19

Correspondence Address:
Ratan K Banik
Department of Anesthesiology, University of Minnesota, Twin Cities Campus, B515 Mayo Memorial Building, 420 Delaware Street S.E., MMC 294, Minneapolis - 55455, MN
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/aca.ACA_191_19

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  [Figure 1]

  [Table 1]