An Intracardiac Flow Based Electromagnetic Energy Harvesting Mechanism for Cardiac Pacing

Strategies for Safe Implantation and Effective Performance of Single-Chamber and Dual-Chamber Leadless Pacemakers

Leadless pacemakers (LPMs) have emerged as an alternative to conventional transvenous pacemakers to eliminate the complications associated with leads and subcutaneous pockets. However, LPMs still present with complications, such as cardiac perforation, dislodgment, vascular complications, infection, and tricuspid valve regurgitation. Furthermore, the efficacy of the leadless VDD LPMs is influenced by the unachievable 100% atrioventricular synchrony. In this article, we review the available data on the strategy selection, including appropriate patient selection, procedure techniques, device design, and post-implant programming, to minimize the complication rate and maximize the efficacy, and we summarize the clinical settings in which a choice must be made between VVI LPMs, VDD LPMs, or conventional transvenous pacemakers. In addition, we provide an outlook for the technology for the realization of true dual-chamber leadless and battery-less pacemakers.

A miniaturized endocardial electromagnetic energy harvester for leadless cardiac pacemakers

Life expectancy of contemporary cardiac pacemakers is limited due to the use of an internal primary battery. Repeated device replacement interventions are necessary, which leads to an elevated risk for patients and an increase of health care costs. The aim of our study is to investigate the feasibility of powering an endocardial pacemaker by converting a minimal amount of the heart's kinetic energy into electric energy. The intrinsic cardiac muscle activity makes it an ideal candidate as continuous source of energy for endocardial pacemakers. For this reason, we developed a prototype able to generate enough power to supply a pacing circuit at different heart rates. The prototype consists of a mass imbalance that drives an electromagnetic generator while oscillating. We developed a mathematical model to estimate the amount of energy harvested from the right ventricle. Finally, the implemented prototype was successfully tested during in-vitro and in-vivo experiments.

Leadless cardiac resynchronization therapy: An in vivo proof-of-concept study of wireless pacemaker synchronization

BACKGROUND

Contemporary leadless pacemakers (PMs) only feature single-chamber ventricular pacing. However, the majority of patients require dual-chamber pacing or cardiac resynchronization therapy (CRT). Several leadless PMs implanted in the same heart would make that possible if they were able to synchronize their activity in an efficient, safe, and reliable way. Thus, a dedicated ultra-low-power wireless communication method for PM synchronization is required.

OBJECTIVE

The purpose of this study was to develop a leadless CRT system and to evaluate its function in vivo.

METHODS

Device synchronization was implemented using conductive intracardiac communication (CIC). Communication frequencies were optimized for intracardiac device-device communication. Energy consumption, safety, and reliability of the leadless PM system were tested in animal experiments.

RESULTS

We successfully performed CRT pacing with 3 independent devices synchronizing their action using CIC. No arrhythmias were induced by the novel communication technique. Ninety-eight percent of all communication impulses were transmitted successfully. The optimal communication frequency was around 1 MHz, with a corresponding transmitted power of only 0.3 μW at a heart rate of 60 bpm.

CONCLUSION

Leadless PMs are able to synchronize their action using CIC and may overcome the key limitation of contemporary leadless PMs.