Unexpected Coronary Sinus Embolization of a Leadless Pacemaker Due to Initial Device Failure: A Case Report

Unexpected Coronary Sinus Embolization of a Leadless Pacemaker Due to Initial Device Failure: A Case Report | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL Clinical Case Reports This is a preprint and has not been peer reviewed. Data may be preliminary. 21 July 2025 V1 Latest version Share on Unexpected Coronary Sinus Embolization of a Leadless Pacemaker Due to Initial Device Failure: A Case Report Authors : Yutaro Oshima 0000-0003-2738-7930 [email protected] , Tsuyoshi Nozue , Masahiro Katamine , and Taku Iwaki Authors Info & Affiliations https://doi.org/10.22541/au.175310315.57931978/v1 Published Clinical Case Reports Version of record Peer review timeline 281 views 158 downloads Contents Abstract Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Background: Leadless pacemakers are increasingly used due to their reduced risk of lead- and pocket-related complications. However, device dislodgment remains a rare but significant risk. Methods and Results We describe an 81-year-old man with bradycardia and atrial fibrillation who experienced intra-procedural Micra device dislodgment caused by inner shaft failure, resulting in Title Page: Unexpected Coronary Sinus Embolization of a Leadless Pacemaker Due to Initial Device Failure: A Case Report Yutaro Oshima, MD, Tsuyoshi Nozue, MD, PhD, Masahiro Katamine MD, PhD, Taku Iwaki, MD From the Department of Cardiology, Yokohama Sakae Kyosai hospital, Kanagawa, Japan. Corresponding Author: [Name] Yutaro Oshima, MD [Full Postal Mailing Address] 132 Katsura-cho, Sakae-ku, Yokohama 247-8581, Japan [Telephone] +81-45-891-2171 [Fax] +81-45-891-2172 [E-mail] [email protected] [Twitter] none Disclosures : [The authors have nothing to disclose] Funding: [The authors received no funding] Key Clinical Message Unexpected coronary sinus embolization of a leadless pacemaker due to initial device failure highlights the need for careful device deployment and post‑procedure imaging to promptly identify malposition. Keywords leadless pacemaker; coronary sinus; device failure; embolization; device retrieval. Introduction The Micra transcatheter pacing system (TPS) has become as popular as conventional pacemakers. Fewer severe and fewer long-term complications than conventional transvenous pacemakers occur because lead and device pocket creation are not required 1,2 . However, acute device dropout has been reported, and there is a need to become familiar with their handling. Micra pacemakers have been reported to drop out because of abnormal cardiac morphology or device crimping failure 3,4 . Herein, we report a case of device dislodgment related to an initial device failure and successful retrieval. Case History/Examination An 81-year-old man was admitted to our hospital with chronic heart failure due to bradycardia and long-standing persistent atrial fibrillation. The patient presented with dyspnea. Physical examination on admission revealed mild edema of the lower extremities. Transthoracic echocardiography revealed good left ventricular function with an ejection fraction of approximately 65%, indicating heart failure with preserved ejection fraction (HFpEF), and moderate tricuspid regurgitation. His heart rate was persistently low at around 20–30 beats per minute. The patient was diagnosed with worsening HFpEF, long-standing persistent atrial fibrillation, and slow ventricular response. Given the marked bradycardia with long-standing persistent atrial fibrillation, a leadless pacemaker was indicated 5 . The leadless pacemaker was implanted the day after admission. The 23 Fr Micra TPS sheath was inserted into the inferior vena cava (IVC) via the right groin. Although part of the inner shaft appeared to be flexed during implantation, we continued the procedure because we thought it would not affect it (Figure1). The Micra pacemaker was implanted in the septal position with suitable sensing and pacing values. Before screwing the device into the myocardium, the impedance was measured at 560 ohms, and the capture threshold was 0.75 V at a pulse width of 0.4 ms, suggesting appropriate electrical parameters. During the procedure, we believed that at least two tines were properly fixed based on the standard pull-and-hold test, and the high tether resistance led us to consider that the device was well secured (However, retrospective evaluation suggested that the tines may not have been adequately engaged). After cutting the tether, we attempted to remove it, but it could not be pulled out. Owing to the breakage within the inner shaft, we subsequently attempted to remove the tether; however, it was assumed that complete extraction was not possible because the tether had become lodged within the damaged shaft. The tether could not be removed using standard techniques. We then applied considerable traction, which inadvertently caused the Micra pacemaker to surge out of the right ventricle and lodge in the coronary sinus. Once the Micra TPS was retrieved from the body, we noted that the inner shaft was damaged (Figure 2). To reposition the device into the right atrium, we advanced a pigtail catheter with a 0.035” guidewire into the coronary sinus via an alpha curve, allowing us to hook and mobilize the Micra pacemaker (Figure 3). The Micra pacemaker was successfully removed from the coronary sinus by hooking the tip of the pigtail catheter onto the tine (Video1). We inserted a steerable introducer (Agilis, Abbott, Abbott Park, Illinois, USA) into the leadless pacemaker sheath and successfully snared the tine with an 18–30 mm multi-loop snare (EN Snare; Merit Medical Systems, South Jordan, USA). However, it was impossible to retrieve the device into the TPS sheath because of interference from the edge of the leadless pacemaker. We then used the double-snare technique to be coaxial. We stopped the movement of the Micra pacemaker by snaring the tine and snaring the retrieval feature with another 12–20 mm multi-loop snare, and the device was successfully removed into the sheath (Figure4, Video 2). We attempted to re-implant the new Micra device and successfully placed it in the septal position. The total procedure time was 195 minutes. Transthoracic echocardiography revealed no pericardial effusion, and the patient was discharged on postoperative day 4. Differential Diagnosis, Investigations and Treatment Differential Diagnosis Device dislodgment secondary to tether failure, anatomical instability, or improper tine fixation. Investigations Fluoroscopy and intra-procedural imaging confirmed device embolization to coronary sinus. Treatment: 1. A 0.035″ guidewire–supported pigtail catheter advanced via alpha curve into coronary sinus to mobilize device (Figure 3, Video 1). 2. Initial single-snare attempt failed. 3. Steerable introducer (Agilis) and two multi-loop snares were used in a double-snare coaxial technique—one snared the tine and one the proximal retrieval feature—to stabilize and recapture device into the delivery sheath (Figure 4, Video 2). 4. A new Micra device was then successfully redeployed in septal position. 5. Total procedure time: 195 minutes. Postoperative echocardiography confirmed no pericardial effusion. Patient discharged on day 4. Results (Outcome and Follow-Up) Percutaneous retrieval of the embolized device was successful without complications. The re-implanted Micra functioned normally. The patient remained asymptomatic, with normal device parameters and no evidence of pericardial effusion. He was discharged on postoperative day 4. Further follow-up showed stable clinical status. Discussion To the best of our knowledge, we report a rare case characterized by initial device failure and the unusual occurrence of a leadless pacemaker becoming lodged in the coronary sinus. Dislodgement can be caused by anatomical abnormalities of the right ventricle, such as cardiac amyloidosis and unstable “cliffhanger” condition 3,4,6 . In our case, the tether could not be extracted owing to the initial breakage of the inner shaft. The most important finding of this case is that initial device failure is sporadic, however, it is associated with a critical complication. The defective catheter was sent back to Medtronic for further analysis, but we have not yet received an official response regarding the cause of the failure. Another unique finding of this case was that the device was embolized into the coronary sinus. Although there have been several case reports of pacemakers becoming stuck in the pulmonary artery 3,7-10 , cases of pacemaker embolization into the coronary sinus are extremely rare, and to the best of our knowledge, only one other case has been reported besides ours 10 . Fortunately, in this case, the Micra device could be easily removed from the coronary sinus because the tines were located toward the entrance of the coronary sinus. If the tine is oriented in the opposite direction, the procedure might be more complicated, or open surgery might be necessary. It was possible to advance the pigtail catheter into the coronary sinus; however, this may not always be possible. The cardiac resynchronization therapy delivery system would make it easier to reach the device (guidewire or multi-loop snare) into the coronary sinus. However, it requires an additional puncture site in the subclavian or jugular vein. The double-snaring technique was effective in making a coaxial between the device and the sheath. There are two approaches to the double-snaring technique: two-puncture two-directional approach 6 and one-puncture two-directional approach. Hasegawa-Tamba et al. reported that a two-puncture two-directional approach with the superior vein cava (SVC) and IVC is easier to operate in some situations because they do not interfere with each other and may have advantages 6 . However, the two-puncture two-directional approach requires an additional puncture site and increases the risk of hemorrhagic complications. Therefore, the one-puncture two-directional approach is a useful option when the two snares do not interfere with each other, thereby avoiding the risk of bleeding complications. Conclusion A leadless pacemaker system is a very useful tool, however, it rarely causes initial device failure. Careful attention should be paid to initial device failure because it may be associated with severe complications. Patient Consent Written informed consent was obtained from patient to publish this report in accordance with the journal’s patient consent policy. Author Contributions Conceptualization: Dr. Oshima Date curation: Dr. Oshima Investigation: All authors Supervision: Dr. Oshima Visualization: Dr. Oshima Writing-original draft: Dr. Oshima Writing-review & editing: Dr. Oshima Acknowledgements The authors thank the Cardiology teams at our center who were involved with this case. Conflict of interest : None declared. References 1. Boveda S, Lenarczyk R, Haugaa KH, et al. 2018. Use of leadless pacemakers in Europe: results of the European Heart Rhythm Association survey. Europace . 20(3):555-559.2. Lenarczyk R, Boveda S, Mansourati J, et al. 2020. Peri-procedural management, implantation feasibility, and short-term outcomes in patients undergoing implantation of leadless pacemakers: European Snapshot Survey. Europace . 22(5):833-838.3. Sterlinski M, Demkow M, Plaskota K, Oreziak A. 2018. Percutaneous extraction of a leadless Micra pacemaker from the pulmonary artery in a patient with complex congenital heart disease and complete heart block. EuroIntervention . 14(2):236-237.4. Fichtner S, Estner HL, Nabauer M, Hausleiter J. 2019. Percutaneous extraction of a leadless Micra pacemaker after dislocation: a case report. Eur Heart J Case Rep . 3(3).5. Glikson M, Nielsen JC, Kronborg MB, et al. 2022. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. Europace . 24(1):71-164.6. Hasegawa-Tamba S, Ikeda Y, Tsutsui K, Kato R, Muramatsu T, Matsumoto K. 2020. Two-directional snare technique to rescue detaching leadless pacemaker. HeartRhythm Case Rep . 6(10):711-714.7. Barbieri F, Kranewitter C, Frech A, Hintringer F, Stuhlinger M. 2021. Lost but Not Lost-Embolization of a Leadless Pacemaker to the Pulmonary Artery with Consecutive Endovascular Recovery. J Cardiovasc Dev Dis . 8(4).8. Romeo E, D’Alto M, Cappelli M, et al. 2021. Retrieval of a leadless transcatheter pacemaker from the right pulmonary artery: A case report. Pacing Clin Electrophysiol . 44(5):952-954.9. Gupta S, Cho K, Papagiannis J, Tisma-Dupanovic S, Borsa J. 2020. A novel technique for extraction of a leadless pacemaker that embolized to the pulmonary artery in a young patient: A case report. HeartRhythm Case Rep . 6(10):724-728.10. Jain S, Alkhalil A, Golbari S, et al. 2019. A Novel Method for a New Problem: Retrieving a Leadless Pacemaker. Journal of the American College of Cardiology . 73(9). Images Figure Legends The right anterior oblique 30° view and left anterior oblique 30° view show that the inner shaft appeared to be flexed. Figure2. After the TPS was removed from the body, the inner shaft was clearly damaged. Figure3. With an alpha curve in the right atrium, the pigtail catheter was advanced into the coronary sinus using a 0.035-inch guidewire. Figure4. First multi-loop snare is holding the tine of Micra pacemaker, and second multi-loop snare is snaring retrieval feature in IVC. Supporting Information Video1. With an alpha curve in the right atrium, the pigtail catheter was advanced into the coronary sinus using a 0.035-inch guidewire. The Micra pacemaker was successfully removed from the coronary sinus by hooking the pigtail catheter to the tine of the device. **Placeholder Image (Video Only) – Video 1:** still frame at **7 s** Video2. Double-snare retrieval of an embolized Micra leadless pacemaker. A steerable sheath was used to deploy two multi-loop snares: the first secured a tine, and the second engaged the proximal retrieval feature to achieve coaxial alignment, stabilize the device, and draw it safely into the delivery sheath. **Placeholder Image (Video Only) – Video 2:** still frame at **42 s** Information & Authors Information Version history V1 Version 1 21 July 2025 Peer review timeline Published Clinical Case Reports Version of Record 29 Sep 2025 Published Copyright This work is licensed under a Non Exclusive No Reuse License. Collection Clinical Case Reports Keyword cardiology Authors Affiliations Yutaro Oshima 0000-0003-2738-7930 [email protected] Yokohama Sakae Kyosai Byoin View all articles by this author Tsuyoshi Nozue Yokohama Sakae Kyosai Byoin View all articles by this author Masahiro Katamine Yokohama Sakae Kyosai Byoin View all articles by this author Taku Iwaki Yokohama Sakae Kyosai Byoin View all articles by this author Metrics & Citations Metrics Article Usage 281 views 158 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Yutaro Oshima, Tsuyoshi Nozue, Masahiro Katamine, et al. Unexpected Coronary Sinus Embolization of a Leadless Pacemaker Due to Initial Device Failure: A Case Report. Authorea . 21 July 2025. DOI: https://doi.org/10.22541/au.175310315.57931978/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. 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