An 88-year-old female, with a history of hepatocyte carcinoma, repeated syncope, and electrocardiograms showed a complete atrioventricular-block. Due to her age and frailty, a leadless pacemaker (LP; Micra, Medtronic, Minneapolis, USA) was implanted in the septum of her right ventricle (RV). Chest radiographs and electrocardiograms showed stable adhesion and performance of the LP (Picture 1). However, two months after the implantation, she suddenly died of hepatocyte carcinoma.
Picture 1.
At autopsy, the anchors of the LP were found to completely invade the trabeculae (Picture 2), and its body was partially covered with a thick capsule (measuring around 2 mm in size) (Picture 3), which firmly adhered to the LP and the RV.
Picture 2.

Picture 3.

Although previous reports have described the adhesion of LPs to RV (1), this is the first report to show such features of LP only two months after placement. Despite such a short time period, the LP showed thick encapsulation and stable adhesion, which would support recent reports on its stable performance (2).
The authors state that they have no Conflict of Interest (COI).
Acknowledgement
We are grateful to the clinical members in the Department of Cardiovascular Medicine, Gastrointestinal Medicine and Pathology at Yamagata Prefectural Central Hospital for their valuable technical assistance.
References
- 1.Tjong FV, Stam OC, van der Wal AC, et al. Postmortem histopathological examination of a leadless pacemaker shows partial encapsulation after 19 months. Circ Arrhythm Electrophysiol 8: 1293-1295, 2015. [DOI] [PubMed] [Google Scholar]
- 2.Knops RE, Tjong FV, Neuzil P, et al. Chronic performance of a leadless cardiac pacemaker: 1-year follow-up of the LEADLESS trial. J Am Coll Cardiol 65: 1497-1504, 2015. [DOI] [PubMed] [Google Scholar]

