Totally Leadless Dual-Device Implantation for Combined Spontaneous Ventricular Tachycardia Defibrillation and Pacemaker Function: A First Report

Perioperative Considerations for Modern Leadless Pacemakers

Since their initial approval by the Food and Drug Administration in 2016, leadless pacemakers have become increasingly prevalent. This growth has been driven by an improved adverse effect profile when compared to traditional pacemakers, including lower rates of infection, as well as eliminated risk of pocket hematoma and lead complications. More recently, technology enabling leadless synchronized atrioventricular pacing in patients with atrioventricular block has vastly expanded the indications for these devices. Anesthesiologists will increasingly be relied upon to safely care for patients with leadless pacemakers undergoing non-electrophysiology procedures and surgery. This article provides an overview of the technology, evidence base, current indications, and unique perioperative considerations for leadless pacemakers.

Simultaneous subcutaneous implantable cardioverter-defibrillator and leadless pacemaker implantation for patients at high risk of infection: a retrospective case series report

BACKGROUND

The subcutaneous implantable cardioverter defibrillator (S-ICD) and leadless pacemaker (LP) are alternative options for patients at high risk of infection requiring ICD and pacing therapy. In this analysis, we described the simultaneous implantation of S-ICD and LP in patients with high infectious risk.

METHODS

The study cohort comprised patients referred to our institution for ICD implantation due to high-risk factors of infection.

RESULTS

Between 2018 and 2022, 13 patients were referred, including 11 with infected ICD and 2 for first ICD implantation in the presence of high-risk factors. In cases of infected ICD, successful extraction was performed using a mechanical dilatation technique. Reimplantation was delayed until resolution of infection with antibiotic therapy. The devices were implanted during a single procedure, with S-ICD implantation following LP placement for verification of sensing adequacy through surface ECG screening. Suitable vectors for sensing during inhibited and ventricular pacing were identified in all patients. Defibrillation testing was effective, and no issues with double counting or undersensing were observed. The postoperative period was uneventful, and during a median follow-up of 35 months, no complications or infections were reported. The median ventricular pacing percentage was 5%, and a single inappropriate shock episode due to myopotential interference was reported and resolved by reprogramming the sensing vector.

CONCLUSION

Simultaneous implantation of S-ICD and LP is feasible and safe in patients at high risk of infection requiring both ICD and pacing therapy. This combined approach provides an effective solution for these patients.

Simultaneous Leadless Pacemaker and Subcutaneous ICD Implantation With Intraoperative Screening: Workflow in Two Patients

A communicating subcutaneous implantable cardioverter-defibrillator (ICD) and leadless pacemaker system is being developed for patients who require both pacing and ICD therapy. It is important to ensure that the paced morphology from the leadless pacemaker will be sensed appropriately by the subcutaneous ICD. We present 2 cases illustrating our approach and workflow. (Level of Difficulty: Intermediate.).

Device orientation of a leadless pacemaker and subcutaneous implantable cardioverter-defibrillator in canine and human subjects and the effect on intrabody communication

Aims

The development of communicating modular cardiac rhythm management systems relies on effective intrabody communication between a subcutaneous implantable cardioverter-defibrillator (S-ICD) and a leadless pacemaker (LP), using conducted communication. Communication success is affected by the LP and S-ICD orientation. This study is designed to evaluate the orientation of the LP and S-ICD in canine subjects and measure success and threshold of intrabody communication. To gain more human insights, we will explore device orientation in LP and S-ICD patients.

Methods and results

Canine subjects implanted with a prototype S-ICD and LP (both Boston Scientific, MA, USA) with anterior-posterior fluoroscopy images were included in this analysis. For comparison, a retrospective analysis of human S-ICD and LP patients was performed. The angle of the long axis of the LP towards the vertical axis of 0°, and distance between the coil and LP were measured. Twenty-three canine subjects were analysed. Median angle of the LP was 29° and median distance of the S-ICD coil to LP was 0.8 cm. All canine subjects had successful communication. The median communicating threshold was 2.5 V. In the human retrospective analysis, 72 LP patients and 100 S-ICD patients were included. The mean angle of the LP was 56° and the median distance between the S-ICD coil and LP was 4.6 cm.

Conclusion

Despite the less favourable LP orientation in canine subjects, all communication attempts were successful. In the human subjects, we observed a greater and in theory more favourable LP angle towards the communication vector. These data suggests suitability of human anatomy for conductive intrabody communication.

Combination of a leadless pacemaker and subcutaneous implantable cardioverter defibrillator therapy for a Japanese patient with prosthetic valve endocarditis

The subcutaneous implantable cardioverter defibrillator (S-ICD) system was developed for defibrillation therapy that does not affect the heart and vasculature. S-ICD is preferred over transvenous ICD for patients with a history of recurrent infection presenting with life-threatening rhythms. Patients with bradycardia pacing indications are excluded from S-ICD therapy, as S-ICD lacks the capability of defibrillation in this patient group. Implantation of an S-ICD with a leadless pacemaker (LP) was proposed to overcome this issue. We describe the first case of successful implantation of S-ICD and LP in a Japanese patient with a history of recurrent prosthetic valve endocarditis.

Simultaneous leadless pacemaker and subcutaneous implantable cardioverter-defibrillator implantation-When vascular options have run out

An end-stage renal failure patient who was planned for a left brachioaxillary arteriovenous graft required an implantable cardioverter-defibrillator for secondary prevention of ventricular tachycardia and a pacemaker for complete heart block but was found to have a right subclavian venous occlusion. Due to the lack of vascular access, we performed a successful subcutaneous implantable cardioverter-defibrillator (S-ICD) and leadless pacemaker implantation. There was no interaction between the devices at the time of implantation, during defibrillation testing and following an appropriate defibrillation therapy.

The modular cardiac rhythm management system: the EMPOWER leadless pacemaker and the EMBLEM subcutaneous ICD

Cardiac implantable electronic devices have been successfully treating patients with brady- and tachyarrhythmias for decades. However, there are still significant complications related to this therapy modality, many related to the transvenous lead. Paradigm-shifting technologies, such as the subcutaneous implantable cardioverter-defibrillator (S-ICD) and leadless cardiac pacemakers (LCP), have emerged to address these complications. The novel modular cardiac rhythm management (mCRM) system, consisting of a communicating antitachycardia pacing-enabled LCP and S‑ICD, is the first system to integrate wireless intrabody communication between devices to allow for coordination of leadless pacing and defibrillator therapy delivery. In this review, the design and concept of the mCRM system are presented and available evidence is summarized.

Initial experience with a leadless pacemaker (Micra™) implantation in a low volume center in South East Asia

Aim:

The Micra™ Transcatheter Pacing System is a leadless pacemaker that has been introduced recently. We share our experience in a low volume center and the use of right ventricular angiography (RVA) during implantation.

Materials & methods:

Patients underwent Micra implantation and RVA was performed to predetermine the implant site.

Results:

Nine patients underwent Micra implantation. The most common indication was atrial fibrillation with bradycardia. The device was implanted at apical-septum in seven and mid-septum in two. The procedure time ranged from 30 to 100 min and fluoroscopic time 4–18 min. Pacing parameters remained stable after 1-month follow-up.

Conclusion:

The Micra implantation technique can be easily learnt. RVA was helpful in selecting an appropriate site for the Micra implant.

Cardiac implantable electronic device and vascular access: Strategies to overcome problems

For arrhythmia treatment or sudden cardiac death prevention in hemodialysis patients, there is a frequent need for placement of a cardiac implantable electronic device (pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization device). Leads from a cardiac implantable electronic device can cause central vein stenosis and carry the risk of tricuspid regurgitation or contribute to infective endocarditis. In patients with end-stage kidney disease requiring vascular access and cardiac implantable electronic device, the best strategy is to create an arteriovenous fistula on the contralateral upper limb for a cardiac implantable electronic device and avoidance of central vein catheter. Fortunately, cardiac electrotherapy is moving toward miniaturization and less transvenous wires. Whenever feasible, one should avoid transvenous leads and choose alternative options such as subcutaneous implantable cardioverter defibrillator, epicardial leads, and leadless pacemaker. Based on recent reports on the leadless pacemaker/implantable cardioverter defibrillator effectiveness, in patients with rapid progression of chronic kidney disease (high risk of renal failure) or glomerular filtration rate <20 mL/min/1.73 m², this option should be considered by the implanting cardiologist for future access protection.

External electrical cardioversion of persistent atrial fibrillation in a patient with a Micra™ Transcatheter Pacing System

We report a case of a 85-year old woman with a preexisting Transcatheter Pacing System (TPS) (Micra™ VR, Fa. Medtronic, Inc., Minneapolis, MN, USA) undergoing several external electrical cardioversions (CV) for symptomatic persistent atrial fibrillation (persAF). Due to bradycardia in the setting of atrial fibrillation a right apical TPS implantation was performed earlier. Four weeks prior to presentation at our facility an unsuccessful CV with a maximum biphasic energy level of 360J was performed, after which amiodarone was initiated. At the time of presentation three shocks with 100 J, 200 J and 360 J were delivered without sustained restoration of a stable sinus rhythm. Patches were in an anterior-posterior position. No complications and no significant changes in device parameters in comparison to the pre-acquired values were observed. To our knowledge, this is the first case report of an external CV in a patient with a TPS. External CV in patients with a preexisting TPS seems to be safe and feasible.