Leadless ventricular pacemaker implant with atrial sensing in levo-transposition of the great arteries

A leadless pacemaker implantation for a patient with systemic right ventricle under ventricular assist device support

Patients with congenitally corrected transposition of the great arteries (ccTGA) often develop complete atrioventricular block and heart failure due to the abnormal disposition of atrioventricular node and disadvantage of systemic right ventricle. These issues are managed with a pacing system and a ventricular assist device (VAD), respectively. While technological advances offer new treatment strategies, the simultaneous deployment of a leadless pacemaker and a VAD in cases of ccTGA remains unexplored. Here, we present a case of leadless pacemaker implantation for a VAD-supported ccTGA patient. The safety of a leadless pacemaker for a subpulmonary left ventricle and electromagnetic interference between devices are major concerns when implanting a leadless pacemaker; however, the current case overcomes these obstacles. There were no perioperative complications, and both devices were functioning without problems during a one-year follow up. We expect that, even in patients with cardiac complexity such as systemic right ventricle under VAD support, a leadless pacemaker could become the treatment of choice if the indication is appropriate, although careful and close follow up is needed.

Learning objective

Technological advances expand treatment strategies and provide significant benefits to patients with adult congenital heart disease (ACHD). However, discussion of the combination of a leadless pacemaker and a ventricular assist device (VAD) is rare. We demonstrated the efficacy of a leadless pacemaker for a subpulmonary left ventricle in a patient with systemic right ventricle on VAD. This approach could be an option even for ACHD patients.

Leadless Pacemakers in Patients with Congenital Heart Disease

Transcatheter leadless pacemakers have benefits in congenital heart disease because they eliminate the risks of lead malfunction, venous occlusions, and pocket complications. This newest pacemaker's utility in this population has been limited by the large sheath and delivery system, need for atrioventricular synchronous pacing, lack of explantation options, and possible lack of adequate access to the subpulmonary ventricle. With careful planning, leadless pacing can be successfully performed in these patients. Consideration of nonfemoral access, alternative implant sites to avoid myocardial scar or prosthetic material, anticoagulation for patients with persistent intracardiac shunts or systemic ventricular implantation, and operator experience are critical.

Leadless Micra pacemaker implantation in patient with previous Senning procedure for dextro-transposition of the great arteries

Leadless pacemakers have been developed with key advantages over traditional transvenous pacemakers by substantially mitigating the risks of device infection and lead related complications, and providing an alternative pacing strategy in patients with barriers to superior venous access. The Medtronic Micra leadless pacing system is designed for implantation through a femoral venous approach across the tricuspid valve, via Nitinol tine fixation into the trabeculated subpulmonic right ventricle. Patients with surgically corrected dextro-transposition of the great arteries (d-TGA) have an increased risk of pacing requirement. There is limited published experience of implantation of leadless Micra pacemakers in this population, with key challenges relating to trans-baffle access, and deployment of the device into the less trabeculated subpulmonic left ventricle. Here we describe a case report of leadless Micra implantation in a 49 year old male with d-TGA and Senning procedure in childhood, who required pacing for symptomatic sinus node disease, with anatomic barriers to transvenous pacing. Micra implantation was successfully performed following careful consideration of patient anatomy, including the utilisation of 3D modelling to guide the implantation procedure.

Micra pacemaker in adult congenital heart disease patients: a case series

INTRODUCTION

implantation of transvenous endocardial or epicardial pacemakers presents specific challenges in adult congenital heart disease (ACHD) patients. Micra leadless pacemaker (Micra PPM) may overcome some of these difficulties.

METHODS

15 ACHD patients who underwent Micra PPM insertion were retrospectively evaluated.

RESULTS

males 53.3%. Mean age at study: 37.5±10.7 years. Mean age at Micra PPM insertion: 35.5±11.0 years. Mean follow-up so far: 2.0±0.3 years. Concerning the ACHD patients, 6.7% had a simple defect, 66.6% had a moderately complex defect, 26.7% were complex. Four patients (26.7%) had a previous PPM implantation. Three patients (20%) had a systemic right ventricle. Two patients (13.3%) had a single ventricle physiology. Five (33.3%) had Trisomy 21. The most commonly used Micra PPM modality was VVI (73.3%). Mean threshold post implantation was 0.48 V [range: 0.25-1.13 V], while mean threshold at 6 months control was 0.60 V [range: 0.38-1.13 V] (p=ns). Mean R wave post implantation was 10.3 V [range: 3.25-19.4 V], whilst mean R wave at 6 months follow-up was 10.1 V [range:3.5-19.0 V] (p=ns). No major peri and post-procedural complications were encountered.

CONCLUSIONS

since ACHD patients are living longer and surviving into adulthood, the incidence of conduction disorders continues to increase, as part of the natural history of some lesions or as early or late complication of surgery. The Micra leadless PPM can be successfully implanted in ACHD patients and have significant theoretical advantages. They should be considered when transvenous and epicardial pacing are either contraindicated or represent an otherwise suboptimal approach. This article is protected by copyright. All rights reserved.

Leadless pacemaker implant guided by intracardiac echocardiography in a patient after Mustard repair

This case report describes a successful leadless pacemaker implant (Micra VR Medtronic, Inc, Minneapolis, MN) in a 48-year-old patient with a history of Mustard repair. Twenty-one years after dual-chamber pacemaker implant, both conventional leads became dysfunctional. Lead extraction was refused by the patient and the subclavian vein was obstructed. A leadless pacemaker was selected as an alternative. Intracardiac echocardiography allowed the safe introduction of the delivery system into the non-systemic left ventricle. Four months after implant, the pacing parameters are stable and the patient is without new complaints. A leadless pacemaker could be considered in patients with complex grown-up congenital heart disease. This article is protected by copyright. All rights reserved.