Introduction: Leadless pacemakers (LPs) have been suggested to have a lower incidence of pacemaker induced cardiomyopathy (PICM) compared with transvenous systems. LPs have also been suggested to cause less frequent and less severe tricuspid valve regurgitation (TVR) when compared to traditional transvenous pacemakers (TVPs). Given limited research in this field, our study aims to better understand the incidence of PICM and TVR in patients with a LP and the factors that affect these incidences. Methods: The study comprised of patients within the National Capital Region Military Health System who received a Medtronic Micra LP from 2017 to 2021 and had a pacing percentage of >20%. Pre-procedural and follow-up echocardiograms were retrospectively assessed to determine the change in left ventricular ejection fraction (LVEF) and the degree of TVR. Given the known impact of the PICM definition on the reported incidence, we assessed rates of PICM using two distinct definitions, 1.) ≥10% decrease in LVEF or 2.) ≥10% decrease in LVEF to an LVEF of <50%. We also assessed the pacemaker implantation location and the change in QRS duration after implantation and pacing. Results: The study included a total of 48 patients. The average age of patients in the study was 77, with 67% males. The most common reason for LP implantation was complete AV block (38%). Pacemaker locations included high (13%), mid (31%), and apical septum (56%). The mean time interval between pacemaker implantation and follow up echocardiogram was 697 days (SD 460). A total of 5 patients (12.5%) met definition 1 for PICM and 3 patients (6.25%) met definition 2. TVR was graded to be more severe than baseline in 37% of patients, unchanged in 32%, and improved in 30%. The average change in QRS duration after pacing was an increase of 46ms with an average QRS duration of 159ms at follow-up. Conclusion: Compared to commonly reported incidences of PICM, LPs appear to have a significantly lower rate of PICM, regardless of the PICM definition used, increase in QRS duration, or implantation location. In this study, LPs did not statistically significantly impact TVR severity.

A document by Adam Kisling. Click on the document to view its contents.

We report a case of incidental detection of severe aortic coarctation, severe secundum atrial septal defect, and bicuspid aortic valve in an active-duty military service member. A single complex minimally invasive procedure successfully corrected his coarctation and atrial septal defect allowing this patient to continue military service.