Author + information
- Received February 16, 2016
- Accepted February 25, 2016
- Published online October 1, 2016.
- aDepartment of Cardiology, J.W. Goethe University, Frankfurt, Germany
- bDepartment of Cardiology, Medical Center, Hungarian Defense Forces, Budapest, Hungary
- ↵∗Reprint requests and correspondence:
Dr. Stefan H. Hohnloser, Division of Clinical Electrophysiology, J.W. Goethe University Hospital, Theodor-Stern-Kai 7, D 60590 Frankfurt, Germany.
Two new leadless pacing systems were recently developed to avoid pocket- and lead-related complications (1,2). There is very limited information regarding long-term healing-in of leadless pacemakers (3).
A 68-year-old man with a history of meningitis, type 2 diabetes mellitus, hypertension, chronic renal failure, aortic stenosis, and aneurysm of ascending aorta (a consequence of infective endocarditis) had undergone 4 complex valvular, aortic, and coronary surgical procedures (replacement of the aortic valve and of the ascending aorta, repeated coronary bypass graft operations).
The patient was referred for pacemaker implantation for newly developed third-degree atrioventricular block in the setting of permanent atrial fibrillation. Given the complex cardiac history with recurrent infective endocarditis, a leadless pacemaker (MICRA transcatheter system, Medtronic Inc., Minneapolis, Minnesota) was successfully implanted in an apical-septal right ventricular location.
After 4 months of clinically stable conditions, the patient was rehospitalized with severe acute-on-chronic renal failure, which led to his death 2 weeks later.
On autopsy, the MICRA pacemaker was found in the apical region of the right ventricle. All 4 nitinol fixation tines of the device were totally embedded in myocardial tissue. The distance between the tip of the MICRA device and the epicardium was 5 mm. Approximately two-thirds of the device was completely covered with endocardial/myocardial tissue (Figures 1 and 2).
The reliability of the fixation methods, the periprocedural risk of cardiac perforation, and the long-term removability represent major, currently still unanswered questions regarding new leadless pacemaker systems. On autopsy of the current case, a stable position of the MICRA device with satisfying security distance from epicardial site of the heart was observed. However, the fact that the MICRA device was deeply encapsulated raises doubts concerning removability of the device after longer periods of time.
Dr. Duray has served on the Speakers’ Bureau for Medtronic. Dr. Hohnloser has received consulting fees from Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received February 16, 2016.
- Accepted February 25, 2016.
- American College of Cardiology Foundation