Reviewed and updated by Valerie Dziados, MSN, CRNP, ANP-C, AGACNP-C: April 11, 2024

Approximately 200,000 pacemakers are implanted annually in the United States, and due to an aging population and increasing pacing indications, this number is expected to grow (Bhatia & El-Chami, 2018). While these devices are effective, approximately one in eight patients has an early complication, usually related to the transvenous lead or subcutaneous pocket. These complications include pneumothorax/hemothorax, cardiac perforation, lead dislodgement/integrity problems, pocket infections/hematomas, endocarditis, vascular obstructions, and tricuspid regurgitation (Bhatia & El-Chami, 2018).  Pacemaker technology has rapidly advanced in the pursuit of decreasing complications and improving outcomes. 

Leadless pacemakers were first proposed in the 1970s and finally gained FDA approval in 2016 (Bhatia & El-Chami, 2018). They are miniature leadless pacing systems that are small enough to be placed inside the heart and avoid the need for a subcutaneous pocket and transvenous leads, the weakest aspects of a traditional pacemaker (Vouliotis, 2023). The leadless pacemaker is dime-sized, free-standing, and inserted via femoral venous access, and in select patients it can be delivered through the transjugular approach (Link, 2024). The pacemaker is affixed to the right ventricular myocardium and released. The delivery system is then removed, and the pacemaker remains embedded in the right ventricle. Currently, there are two systems available:  Micra (Medtronic) and Aveir (Abbott). Micra received FDA approval in 2016 and Aveir in 2022 (Link, 2024).

 The leadless pacemakers have a battery longevity of five to ten years, which is comparable to traditional devices (Grippe, 2019). The initial models were capable of VVI or VVIR (ventricular demand pacing where only the ventricle is paced, sensed, and the pulse generator inhibits pacing output in response to a sensed ventricular event) pacing. A newer model, named Micra AV, offers the capacity to maintain AV synchrony by sensing atrial activity and pacing the ventricle using an accelerometer-based algorithm, thus providing VDD pacing. Additionally, there is the Aveir DR, which is an investigational device that includes implanting one device in the right atrium and one device in the right ventricle to provided AV synchrony (Link, 2024).

Preliminary reports of long-term performance and complications are promising, including low complications, few system revisions, and stable pacing parameters. These pacemakers maybe a good option for patients who have difficult vascular access, an expected low burden of need for pacing (i.e., severe recurrent vasovagal syncope), an expected high risk of infection, or those who have had prior implantable cardiac device infection (Link, 2024). Leadless pacemakers are also cosmetically appealing because there is no chest incision or visible pacemaker pocket and they are MRI compatible (Grippe, 2019).

Future avenues of development in this specialized area include transforming kinetic energy from cardiac motion to fuel the pacemaker to allow for a battery-free pacemaker, wireless left ventricular pacing system, potentially utilizing leadless pacemakers with subcutaneous defibrillators (Vouliotis, et al., 2023).

References: 

Bhatia, N., & El-Chami, M. (2018). Leadless pacemakers: a contemporary review. Journal of geriatric cardiology : JGC, 15(4), 249–253. https://doi.org/10.11909/j.issn.1671-5411.2018.04.002

Grippe, G.A. (2019). The leadless pacemaker: an innovative design to enhance pacemaking capabilities. Journal of the American Academy of Physician Assistants, 32(6), 48-50. https://www.doi.org/10.1097/01.JAA.0000554750.85170.d4    

Link, M. (2024, March). Permanent cardiac pacing: overview of devices and indications. UpToDate. https://www.uptodate.com/contents/permanent-cardiac-pacing-overview-of-devices-and-indications

Vouliotis, A., Roberts, P., Dilavernis, P., Gatzowlis, K., Yue, A., & Tsioufis, K. (2023). Leadless pacemakers: current achievements and future perspectives. European Cardiology, 18: e49. https://www.doi.org/10.15420/ecr.2022.32