Scientific Publications for Cardiac Rhythm Management
Summary
- FDA-approved labeling for Micra™ AV and Micra™ AV2 leadless pacemakers includes contraindications for concomitant use with another implanted cardiac device providing active cardiac therapy that could interfere with the sensing performance of the Micra™ AV and Micra™ AV2 leadless pacemakers and if another implanted device could interfere with the implant of the Micra™ AV and Micra™ AV2 leadless pacemakers in the judgment of the implanting physician.
- The use of the Micra™ AV and Micra™ AV2 transcatheter pacing systems with a concomitant transvenous or leadless pacemaker providing atrial pacing has not been studied prospectively. The case reports below describe clinical scenarios of this concomitant use case:
- Nine case reports describe patients who present with a dual chamber transvenous pacemaker with a failing right ventricular lead. Clinical solutions considered to address the failing right ventricular lead include 1) right ventricular lead extraction followed by replacement with a new transvenous right ventricular lead; 2) cap and abandon the failing transvenous right ventricular lead followed by implantation of a new transvenous right ventricular lead; 3) cap and abandon the failing transvenous right ventricular lead and implant of a Micra™ AV or Micra™ AV2 leadless pacemaker for use concomitantly with the existing transvenous atrial pacemaker.
- One case report describes implantation of two leadless pacemakers (one for right atrial pacing and Micra™ AV2 leadless pacemaker for right ventricular pacing) during a single procedure in a patient with congenital heart disease and complex anatomy.
- In each case, the clinical rationale for the concomitant implant approach is provided with the need to address the following clinical needs:
- Need to provide atrioventricular (AV) synchrony
- Venous access challenges potentially complicating implantation of another transvenous lead
- Lead extraction risks, particularly in elderly and fragile patients
- Recurrent failure of prior transvenous right ventricular leads
- Infection risks associated with transvenous lead implantation
- Given that these are independent case reports, the results should be considered in the context of the following limitations:
- The case reports address specific clinical scenarios and patient histories that may not be applicable to a broad patient population.
- The presence of two pacemakers that do not communicate may introduce the possibility of device interaction that may result in pacemaker inhibition. Device interaction testing was not routinely assessed in the case reports included.
- Long-term safety and efficacy of this use have not been evaluated; the case reports describe acute (immediately post-implant) and short-term (one to six months) follow-up data.
- Consideration should be given to differences in end-of-service indicator timing for multiple devices and management of future generator replacement.
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Articles of interest
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 69-year-old woman with past medical history of sinus node dysfunction, Mobitz II AV block, dual chamber pacemaker, and left-side atrioventricular fistula for end-stage renal disease admitted for syncope due to chronically malfunctioning right ventricular lead. Authors acknowledge that the implant situation is “extremely rare” owing to unique risk associated with re-accessing the left axillary vein due to patient’s atrioventricular fistula and highlight importance of caution and care given potential adverse interactions between two distinct cardiac implantable electronic devices that do not directly communicate with each other and the potential for pacing inhibition in the absence of appropriate device programming.
- One day post-operative telemetry demonstrated atrial pacing from the transvenous device and appropriate ventricular pacing from the Micra™ AV leadless pacemaker and thus the patient was discharged.
Source: Siroky GP, Bisht D, Huynh H, Mohammad A, Mehta D, Lam P. Synchronization of the new leadless transcatheter pacing system with a transvenous atrial pacemaker: A case report. HeartRhythm Case Rep. 2020;6(12):899–902. doi:10.1016/j.hrcr.2020.08.014.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 74-year-old woman with past medical history of tetralogy of Fallot, atrial flutter, multiple cardiac surgeries (pulmonary and aortic valve replacement, right ventricular outflow tract root, and aortic root repairs), complete heart block, and transvenous dual chamber pacemaker with fractured right ventricular lead. Authors opted for use of a “nontraditional, hybrid” pacing system with two different pacemaker generators based on shared decision-making with patient that considered risk of cross talk between systems and uncertainty in mechanical sensing of an atrial-paced rhythm. Authors noted that the patient’s “right atrial and right ventricular dilation provided a large anatomic distance between the leadless pacemaker and right atrial lead, which made cross talk less likely; however, in patients with smaller hearts, this could be a significant concern.”
- Testing for cross talk between devices was done during implant procedure and no oversensing was noted after adjustments to programming and positioning of the devices.
- Two important issues were noted during implant of the Micra™ AV leadless pacemaker when the leadless pacemaker programmer’s head was placed on the patient’s chest. First, the preexisting dual chamber pacemaker occasionally went into magnet mode, although this was typically short-lived and resulted in no adverse events. Second, the preexisting dual chamber pacemaker programmer had difficulty initiating a connection with the preexisting pacemaker likely due to magnetic field in the leadless pacemaker programmer head. This issue was resolved when the programmer head was removed.
Source: Needleman M, Symons J, Weber LA, Mulreany M, May J, Haigney MC. Novel use of an atrial sensing leadless pacemaker to treat complete heart block in a patient with repaired tetralogy of Fallot with pre-existing dual chamber pacemaker with ventricular lead fracture. HeartRhythm Case Rep. 2020;6(10):777-781. doi:10.1016/j.hrcr.2020.07.019.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 92-year-old man with past medical history of dementia, chronic kidney disease, high grade AV block, sinus node dysfunction, dual chamber pacemaker with apparent right ventricular lead fracture presenting with symptomatic bradycardia, and atrioventricular block. Considerations for the implant decision included unreliability of continuous unipolar pacing in the pacemaker-dependent patient, the high risk of fall due to gait instability, the patient’s elderly age, and prior right ventricular lead failure.
- Acute implant and three-month follow-up data are reported.
Author disclosures:
Waddah Maskoun reported a grant from Medtronic.
Source: Nona P, Altawil M, Khan E, Maskoun W. Dual chamber pacing using a hybrid transvenous and leadless pacing approach. Pacing Clin Electrophysiol. 2021;44(4):751–754. doi:10.1111/pace.14190.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 71-year-old man with past medical history of coronary artery disease, aortocoronary bypass, mitral valve replacement, sinus node dysfunction, intermittent AV block, and transvenous dual chamber pacemaker presenting with elevated right ventricular pacing capture threshold and complete occlusion of the right subclavian vein. Placement of a new transvenous ventricular lead on the same side was not possible due to occlusion, and implant of an additional ventricular lead through the left subclavian vein risked exacerbating already severe tricuspid regurgitation.
- Dyssynchronous pacing developed after initial success in atrioventricular synchronization between the two pacemakers, and a description of the required programming changes to achieve adequate atrioventricular synchrony over the first 15 days following implant is provided. History of aortocoronary bypass is reported as a risk factor for low atrioventricular synchrony.
Source: Teodorovich N, Paz O, Jaber M, Haber G, Diamante R, Swissa M. Long-term synchronization of old transvenous dual chamber pacemaker and newly implanted leadless ventricular pacemaker with atrial sensing capability. HeartRhythm Case Rep. 2021;7(9):615–619. doi:10.1016/j.hrcr.2021.06.005.
Medtronic-generated summary
- Right ventricular lead extraction preceded the Micra™ AV leadless pacemaker implant in a 66-year-old woman with year-long history of exertional dyspnea, peripheral edema, postural neck pulsations, long-term history of hypertension, type II diabetes, hypothyroidism, previous excision of benign left atrial myxoma, previous ablation for typical atrial flutter, and dual chamber transvenous pacemaker. Transthoracic echocardiogram revealed severe tricuspid regurgitation due to apparent tethering of the septal leaflet of the tricuspid valve by the right ventricular lead.
- As the patient required 100% atrial pacing, the existing atrial lead was connected to a single chamber transvenous pacemaker with the goal of concomitant use with the Micra™ AV leadless pacemaker.
- Two weeks post-procedure follow-up demonstrated no changes in patient symptoms or tricuspid regurgitation despite the presence of adequate atrioventricular synchrony. The patient remained markedly breathless, described ongoing pedal edema and had severe residual eccentric tricuspid regurgitation confirmed via transthoracic echocardiography. Future tricuspid valve surgery was planned but was not reported at the time of publication.
Author disclosures:
Fozia Ahmed reported previous research funding and honoraria from Medtronic.
Colin Cunnington reported honoraria and speaking fees from Medtronic.
Amir Zaidi reported honoraria from Medtronic.
Source: Guella E, Devereux F, Ahmed FZ, Scott P, Cunnington C, Zaidi A. Novel atrioventricular sequential pacing approach using a transvenous atrial pacemaker and a leadless pacemaker: a case report. Eur Heart J Case Rep. 2021;5(7):ytab219. doi:10.1093/ehjcr/ytab219.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in 90-year-old man with new-onset intermittent dizziness and past medical history of coronary artery bypass surgery, hypertension, chronic obstructive pulmonary disease, hyperthyroidism, and right-sided dual chamber pacemaker with three abandoned transvenous leads from a prior left-sided pacemaker.
- At the six-week follow-up visit, adequate atrioventricular synchrony was observed.
Source: Bodagh N, Cheng K, Eysenck W, Wong T. Synchronous atrioventricular sequential pacing utilizing conventional and leadless pacemakers in an elderly patient: a case report. Eur Heart J Case Rep. 2022;7(1):ytac474. doi:10.1093/ehjcr/ytac474.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 90-year-old woman with past medical history of moderate chronic kidney disease and dual chamber pacemaker for symptomatic sinus node dysfunction presenting with syncope and complete atrioventricular block due to intermittent loss of right ventricular lead capture. Patient was implanted with leadless pacemaker due to high risk of cardiac implantable electronic device–related infection based on risk factors such as history of early device reintervention, ventricular lead dysfunction, and renal impairment.
- At the one- and six-month follow-up visits, adequate atrioventricular synchrony was noted.
Source: Zeriouh S, Sousonis V, Menè R, Boveda S, Voglimacci-Stephanopoli Q, Combes S. Case report: A leadless and endovascular pacemaker teamwork. Front Cardiovasc Med. 2023;10:1287506. doi:10.3389/fcvm.2023.1287506.
Medtronic-generated summary
- The Micra™ AV leadless pacemaker was implanted in a 77-year-old man with history of severe conduction disease, chronic kidney disease, paroxysmal atrial fibrillation, coronary artery disease, ischemic cardiomyopathy, and dual chamber transvenous pacemaker with previously abandoned right ventricular lead presenting with recurrent syncope. The Micra™ AV leadless pacemaker was implanted without extraction of failed leads or implantation of additional transvenous leads due to the patient’s history of recurrent right ventricular lead failures and high risk associated with lead extraction.
- At the eight-week follow-up visit, adequate atrioventricular synchrony was observed; however, given the short follow-up period and the patient’s sedentary lifestyle, it is possible these results are not broadly applicable to other patients.
Source: Margolis G, De-Levie TK, Barel MS, et al. Short-term synchronization of an intracardiac leadless pacemaker with a transvenous atrial pacemaker in a sedentary patient. JACC Case Rep. 2024;29(22):102666. doi:10.1016/j.jaccas.2024.102666.
Medtronic-generated summary
- A 27-year-old male patient with history of complex congenital heart disease (dextrocardia with double-outlet right ventricle with subaortic septal defect and pulmonary stenosis, multiple pulmonary valve replacements, moderate tricuspid regurgitation, symptomatic atrial arrhythmia, prior right-sided dual chamber transvenous ICD) and stage 4 liver disease developed pocket infection and small device erosion after ICD generator change, necessitating transvenous lead extraction.
- Following lead extraction, a Micra™ AV2 leadless pacemaker was implanted in the right ventricle followed by placement of the AVEIR™* leadless pacemaker system at the superior base of the right atrial appendage. This therapeutic option was chosen due to the patient’s high risk of infection, endocarditis, multiple prior sternotomies, and moderate tricuspid regurgitation.
- Device interaction testing confirmed the absence of cross talk at implant and via daily telemetry assessments the week following implant.
- At six-month follow-up visit, electrical parameters were stable in both leadless pacemakers.
Source: English C, Fan D, Ing F, Cortez D. Different leadless pacemakers working in harmony (Aveir in the atrium/Micra AV2 in the ventricle) in a patient with dextrocardia and double outlet right ventricle after high-risk infected device extraction. J Cardiovasc Electrophysiol. 2024;35(3):418–421. doi:10.1111/jce.16173.
Medtronic-generated summary
- The Micra™ AV2 leadless pacemaker was implanted in an 82-year-old male with history of sinus node dysfunction, complete atrioventricular block, and recent transvenous dual chamber pacemaker generator replacement with apparent lead insulation breach in the right ventricular lead. In choosing this therapeutic option, the authors considered risk of old lead extraction procedure, risk of device infection, disadvantage of an increased number of transvenous leads, and potential to facilitate synchronous atrioventricular pacing in conjunction with the transvenous pacemaker.
- Adequate atrioventricular synchrony was reported following implant and through the four-month follow-up visit.
- Device interaction testing confirmed the absence of cross talk.
Source: Wakabayashi Y, Shoda M, Uesako H, Kobayashi M, Ichikawa T, Abe H. Atrioventricular synchronous pacing using a transvenous right atrial lead and an atrial mechanical sensing leadless pacemaker. HeartRhythm Case Rep. 2025;11(7):621-625. doi:10.1016/j.hrcr.2025.04.003.
Disclosures
Micra™ AV and Micra™ AV2 leadless pacemakers have not been approved by FDA for concomitant use with an active transvenous pacemaker providing atrial pacing and the safety and effectiveness of concomitant use of Micra™ AV and Micra™ AV2 leadless pacemakers with an active transvenous pacemaker providing atrial pacing has not been established.
The FDA approved use for Micra™ AV and Micra™ AV2 leadless pacemakers are as follows:
The Micra™ AV Model MC1AVR1 is indicated for use in patients who have experienced one or more of the following conditions:
- Paroxysmal or permanent high-grade AV block in the presence of AF
- Paroxysmal or permanent high-grade AV block in the absence of AF, as an alternative to dual chamber pacing, when a dual chamber transvenous pacing system is considered difficult, high risk, or not deemed necessary for effective therapy
- Symptomatic bradycardia-tachycardia syndrome or sinus node dysfunction (sinus bradycardia or sinus pauses), as an alternative to atrial or dual chamber pacing, when a dual chamber transvenous pacing system is considered difficult, high risk, or not deemed necessary for effective therapy
The device is also indicated for VDD pacing in patients with adequate sinus rates who may benefit from maintenance of AV synchrony. The Micra™ AV leadless pacemaker provides AV synchronous ventricular pacing similar to a transvenous VDD system. The implanted device depends on the appropriate sensing of atrial mechanical signals to achieve AV synchrony. The level of AV synchrony may vary in individual patients and may not be predictable prior to implant. Rate-responsive pacing is indicated to provide increased heart rate appropriate to increasing levels of activity.
The device is designed to be used only in the right ventricle.
Micra™ AV2 Model MC2AVR1 is indicated for VDD pacing in patients when a dual chamber transvenous pacing system is considered a poor option or not deemed necessary for effective therapy, and when a right ventricular transcatheter pacing system promoting atrioventricular synchrony at rest is acceptable. Conditions when a patient is considered a poor candidate for transvenous pacing may include, but are not limited to, tortuous anatomy, a need to preserve venous access, or increased risk of infection. The device provides atrioventricular synchrony at rest and rate responsive (VVIR) pacing during periods of high patient activity. Device-mediated atrioventricular synchrony can vary depending on patient condition and activity levels, and it can be limited at high sinus rates. During periods of intermittent atrioventricular synchrony, the device will provide ventricular pacing support with an increased potential for pacing rate variability. The Micra™ AV2 leadless pacemaker is indicated for use in patients who have experienced one of the following:
- Paroxysmal or permanent high-grade AV block in the absence of AF
- Paroxysmal or permanent high-grade AV block in the presence of paroxysmal AF
- Paroxysmal or permanent high-grade AV block in the presence of persistent AF when attempts at restoring sinus rhythm are still planned
The device is designed to be used only in the right ventricle.
Pre-implant considerations
The Micra™ AV and Micra™ AV2 leadless pacemakers are intended to provide AV synchrony at rest and VVIR pacing during periods of high patient activity. Synchronous ventricular pacing using sensing of atrial mechanical contraction may not provide continuous AV synchrony. Device-mediated AV synchrony can vary depending on patient condition and activity levels, and it can be limited at high sinus rates. During periods of intermittent AV synchrony, the device will provide ventricular pacing support with increased potential for pacing rate variability.
The decision to implant the Micra™ AV or Micra™ AV2 leadless pacemaker should consider the benefits of leadless pacing versus the patient’s need for continuous AV synchrony.
Some patients will not benefit from the AV synchronous (VDD) mode. Patients with the following conditions should be considered for a dual chamber transvenous pacing system:
- Sinus node dysfunction
- High sinus rates requiring atrial tracking
- Weak atrial contraction
- Symptoms during loss of AV synchrony
- Frequent premature atrial or ventricular contractions where atrial tracking is required immediately after the premature beat
Patient evaluation for the implant of the Micra™ AV Model MC1AVR1 or Micra™ AV2 Model MC2AVR1 should include that the leadless pacemaker may be fully encapsulated prior to the End of Service (EOS) condition.
Patient evaluation for the implant of the Micra™ AV Model MC1AVR1 or Micra™ AV2 Model MC2AVR1 should include the following consideration about a concomitant implant with a neurostimulator:
Concomitant neurostimulator and cardiac device implants – Some patients have medical conditions that require the implant of both a neurostimulator and a cardiac device (for example, a pacemaker, a defibrillator, or a monitor). In this case, physicians (for example, a neurologist, a neurosurgeon, a cardiologist, and a cardiac surgeon) involved with either device should contact Medtronic Technical Services or their Medtronic representative before implanting the patient with the second device. Based on the particular devices that the physicians have prescribed, Medtronic can provide the necessary precautions and warnings related to the implant procedure. For information about how to contact Medtronic, see the telephone numbers and addresses provided on the back cover of this manual.
The FDA-required labeling contains the following Warnings, Precautions and Cautions about this off-label use of Micra™ AV and Micra™ AV2 leadless pacemakers:
Concomitant neurostimulator and cardiac device implants – Some patients have medical conditions that require the implant of both a neurostimulator and a cardiac device (for example, a pacemaker, a defibrillator, or a monitor). In this case, physicians (for example, a neurologist, a neurosurgeon, a cardiologist, and a cardiac surgeon) involved with either device should contact Medtronic Technical Services or their Medtronic representative before implanting the patient with the second device. Based on the particular devices that the physicians have prescribed, Medtronic can provide the necessary precautions and warnings related to the implant procedure. For information about how to contact Medtronic, see the telephone numbers and addresses provided on the back cover of this manual.
Multiple devices – The use of deactivated Micra™ AV and Micra™ AV2 leadless pacemakers in situ and an active Micra™ AV or Micra™ AV2 leadless pacemaker, or an active transvenous pacemaker or defibrillator, has not been clinically tested to determine whether EMI or physical interaction is clinically significant. Bench testing supports that implantation of an active Micra™ AV or Micra™ AV2 leadless pacemaker, or an active transvenous pacemaker or 14 defibrillator, next to an inactivated Micra™ AV or Micra™ AV2 leadless pacemaker is unlikely to cause EMI or physical interaction. Post-approval studies are planned to characterize risks of co-implanted, deactivated Micra™ AV and Micra™ AV2 leadless pacemakers. Currently recommended end of device life care for a Micra™ AV or Micra™ AV2 leadless pacemaker may include the addition of a replacement device with or without explantation of the Micra™ AV or Micra™ AV2 leadless pacemaker, which should be turned off.
Patient’s age and medical condition – The patient’s age and medical condition should be considered by physicians and patients as they select the pacing system, mode of operation, and implant technique best suited to the individual.
Prosthetic tricuspid valve – Use caution when implanting a Micra™ AV or Micra™ AV2 leadless pacemaker in a patient with a prosthetic tricuspid valve to avoid valve damage. During device implant, visualizing the prosthetic valve using the LAO fluoroscopic view can aid in limiting interaction with the valve leaflets.
End of Service (EOS) – Neither the Micra™ AV nor Micra™ AV2 leadless pacemaker is intended to be removed following the End of Service (EOS) condition. Note: Removal of the Micra™ AV or Micra™ AV2 leadless pacemaker may be difficult because of its deeper implant site in the heart and the development of fibrotic tissue. If removal of the device is required, refer the patient to a medical center that has expertise in the removal of implanted leads (particularly with cardiac surgery backup) or call a Medtronic representative for more information.
Potential Adverse events
The following are known potential adverse events associated with the use of the Micra™ AV leadless pacemaker.
Note: Implant and usage of this product may result in adverse events, which may lead to injury, death, or other serious adverse reactions.
- Acute tissue trauma
- Air embolism
- Allergic reaction
- AV fistula
- Bradyarrhythmia
- Cardiac arrest
- Cardiac inflammation
- Cardiac perforation
- Cardiac tamponade
- Cardiac valve damage
- Coronary sinus dissection
- Device embolization
- Device migration
- Discomfort
- Dizziness
- Dyspnea
- Embolism
- Endocarditis
- Excessive fibrotic tissue growth
- Extracardiac stimulation
- Fever
- General surgery risks and complications from comorbidities, such as hypotension, pneumonia, hypertension, cardiac failure, renal failure, and anemia
- Heart block
- Heart failure decompensation (hospitalization)
- Hematoma
- Hemorrhage
- Hemodynamic compromise
- Hemothorax
- Hiccups
- Hospitalization
- Impaired cardiac function (due to device)
- Inability to deliver therapy
- Infection
- Lethargy
- Loss of pacing
- Mental anguish
- Necrosis
- Nerve damage
- Onset of persistent AF
- Oversensing
- Pacemaker syndrome
- Palpitations
- Pericardial effusion
- Pericarditis
- Peripheral ischemia
- Pneumothorax
- Pseudoaneurysm
- Return of cardiac symptoms
- Seroma
- Skeletal muscle sensation/twitching
- Syncope
- Threshold elevation
- Thrombosis
- Tissue trauma
- Toxic reaction
- Undersensing
- Undesirable impact to proximal medical equipment
- Vascular tear
- Vessel dissection
- Vessel perforation
- Wound dehiscence
The following are known potential adverse events associated with the use of the Micra™ AV2 leadless pacemaker.
Note: Implant and usage of this product may result in adverse events, which may lead to injury, death, or other serious adverse reactions.
- Air embolism
- Allergic reaction
- AV fistula
- Bradyarrhythmia
- Cardiac arrest
- Cardiac inflammation
- Cardiac perforation
- Cardiac tamponade
- Cardiac valve damage
- Device embolization
- Device migration
- Discomfort
- Dizziness
- Dyspnea
- Embolism
- Excessive fibrotic tissue growth
- Extracardiac stimulation
- Fever
- Groin entry site injury
- Heart block
- Heart failure decompensation (hospitalization)
- Hematoma
- Hemorrhage
- Hemodynamic compromise
- Hemothorax
- Hiccups
- Hospitalization
- Impaired cardiac function (due to device)
- Inability to deliver therapy
- Infection
- Lethargy
- Loss of pacing
- Mental anguish Necrosis
- Nerve damage
- Onset of persistent AF
- Oversensing
- Pacemaker syndrome
- Palpitations
- Pericardial effusion
- Peripheral ischemia
- Physical injury
- Pneumothorax
- Pseudoaneurysm
- Return of cardiac symptoms
- Seroma
- Skeletal muscle sensation/twitching
- Skin disorders
- Syncope
- Threshold elevation
- Thrombosis
- Tissue trauma
- Toxic reaction
- Undersensing
- Undesirable impact to proximal medical equipment
- Vascular tear
- Vascular trauma
- Vessel perforation
- Wound dehiscence
FDA approved labeling
Contraindications
The FDA approved labeling for Micra™ AV and Micra™ AV2 leadless pacemakers include the following contraindications:
Micra™ AV Model MC1AVR1 and Micra™ AV2 Model MC2AVR1 devices are contraindicated for use in the following situations:
- If an implanted inferior vena cava filter is present and jugular venous anatomy is unable to accommodate a 7.8 mm (23 Fr) introducer sheath or implant on the right side of the heart (for example, due to obstructions or severe tortuosity).
- If a mechanical tricuspid valve is present
- If another implanted cardiac device providing active cardiac therapy may interfere with the sensing performance of the Micra™ AV or Micra™ AV2 leadless pacemaker
- If another implanted device would interfere with the implant of the Micra™ AV or Micra™ AV2 leadless pacemaker in the judgment of the implanting physician
- If venous anatomy is unable to accommodate a 7.8 mm (23 Fr) introducer sheath or implant on the right side of the heart (for example, due to obstructions or severe tortuosity).
- If morbid obesity prevents the implanted device from obtaining adequate telemetry communication within 12.5 cm (4.9 in)
- If known intolerance to heparin or the tissue contacting materials in the device exists
- If sensitivity to contrast media cannot be adequately premedicated
- If the steroid dose from this device cannot be tolerated
For the MRI contraindications for patients with a Micra™ AV or Micra™ AV2 leadless pacemaker, refer to the Micra™ AV or Micra™ AV2 leadless pacemaker technical manual.