Percutaneous epicardial pacing in infants using direct visualization: A feasibility animal study

Temporary Pacing for Electric Cardiac Stimulation and Neuromodulatory Cardiovascular Therapy

The widespread prevalence and significant consequences of cardiac arrhythmias have been addressed by adopting cardiac stimulation and neuromodulation implantable devices. The oldest, most commonly employed, and most well-known technology is the permanent transvenous cardiac pacemaker. However, in select emergent clinical scenarios and transient pathologies, temporary pacing is preferred. More recently, neuromodulatory vagal nerve stimulation has emerged to address neurologic, psychiatric, and nociceptive pathologies, generating significant clinical and scientific interest in the invention of temporary corollary devices for a subset of indications of nociceptive origin. The dominance of particular implant approaches and anatomic targets in both temporary pacing and neuromodulation in the clinic is owed to capabilities and limitations present in the current technological landscape. However, recent innovations in industry and academia may lead to a fundamental shift in how temporary pacing and neuromodulation are delivered in terms of procedural approach and patient outcomes. In this review, we present an overview of contemporary temporary pacemakers, neuromodulatory therapies, and devices, highlighting novel temporary pacing technologies from the clinic, industry, and academia, such as temporary permanent pacemakers, innovations in non-blood-contacting devices, bioresorbable pacemakers, and advances in neuromodulatory approaches.

Multicenter Results of a Novel Pediatric Pacemaker in Neonates and Infants

BACKGROUND

To address the unmet need for a smaller pacemaker for babies, a specially modified implantable pulse generator was developed containing a Medtronic Micra subassembly in a polymer header connecting to a bipolar epicardial lead. The aim of this study was to report midterm follow-up data and outcomes of patients who underwent implantation of this device.

METHODS

Deidentified data were collected from 12 of 15 sites in the United States implanting the pediatric implantable pulse generator between March 2022 and February 2024. All 29 patients at these 12 sites within this timeframe were included in the analysis.

RESULTS

The median age at implant was 15 days (range, 0 days to 3 years, including 1 outlier). The median weight was 2.3 kg (range, 1.3-11.4 kg). Gestational age was 28.5 weeks to term, with 23 (79%) patients born prematurely. Of those with anatomic information, 25% had congenital heart disease. The average duration of implant was 325 days (73-808 days). The most recent lead impedance mean was 612 ohms (450-840 ohms), ventricular capture threshold mean was 1 V @ 0.4 ms (range, 0.38-2.75 V), and R-wave sensing mean was 12.5 mV (3.6-20 mV). There were 7 generator explants (24%), removed at 6.5 to 31 months of age.

CONCLUSIONS

The pediatric implantable pulse generator can be safely implanted in neonates and infants. This multicenter report demonstrates that the devices remain stable, with effective pacing, normal electrical parameters, and battery longevity aligned with projections. This novel pediatric pacemaker provides a viable alternative to standard-size generators and addresses a vital unmet need for these small patients.

A leadless pericardial pacemaker

BACKGROUND

Cardiac pacemakers have complications related to long pacemaker leads, subcutaneous pockets, and endovascular hardware.

OBJECTIVE

We report on the development of a leadless micropacemaker for percutaneous implantation into the pericardial space.

METHODS

Percutaneous implantations of a micropacemaker system were performed in 15 pigs through subxiphoid access to the pericardial space. In our concept phase, 10 implants were performed with iterative changes to the design and implantation techniques until a design was reached for a viable device. In the study phase, a viable device was implanted in 5 pigs and observed during 8 weeks.

RESULTS

At the completion of the concept phase, a prototype micropacemaker device was fabricated that met 3 mandatory system requirements: can be safely and reproducibly implanted percutaneously into the pericardial space; does not migrate after implantation; and successfully captures the myocardium at implantation and during long-term follow-up (up to 8 weeks). The prototype device was successfully and safely implanted into all 5 pigs in the study phase. These 5 animals survived to the 8-week end point without complications. Ventricular capture threshold calculations at implantation were a median 0.43 V at 0.4 ms (range, 0.05-0.75 V at 0.4 ms). At 8 weeks of follow-up, median capture thresholds were 2.8 V at 0.4 ms (total range, 2.2-7.1 V).

CONCLUSION

A novel pericardial micropacemaker system allows minimally invasive implantation of a leadless cardiac pacemaker without entering the vascular space. We provide proof of concept of this design with encouraging follow-up data.