Analytical Modeling for Computing Lead Stress in a Novel Epicardial Micropacemaker

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Pediatric Cardiology

Background:

• Pediatric cardiac pacing presents challenges due to patient size and congenital defects.
• Existing pacing systems require invasive implantation and may not accommodate growth.
• A novel, minimally invasive epicardial micropacemaker is under development for children.

Purpose of the Study:

• To develop and evaluate a novel open-coiled lead for a pediatric epicardial micropacemaker.
• To create a radiographic image-based model to predict in vivo lead behavior and stress.
• To assess the feasibility of a minimally invasive implantation technique in an animal model.

Main Methods:

• Implantation of dummy micropacemakers with epicardial leads in an adult pig model via minimally invasive surgery.
• Acquisition of fluoroscopic images at multiple time points post-implantation.
• Construction of an analytic model using radiographic images to determine lead deformation and stress distribution during cardiac cycles.

Main Results:

• The radiographic modeling approach successfully estimated in vivo stress conditions on the lead.
• Maximum stress concentrations were identified at the lead's exit point from the pericardial space.
• Mean stress reached 531.4 MPa, with alternating stress of ±216.4 MPa, indicating potential failure points.

Conclusions:

• The developed modeling approach provides a foundation for optimizing the epicardial lead design.
• Further animal testing and modeling are necessary to validate the lead's durability for long-term pediatric use.
• The findings guide improvements for a novel, less invasive cardiac pacing solution for children.