An intracardiac electrogram model to bridge virtual hearts and implantable cardiac devices

TL;DR

This paper introduces an intracardiac electrogram model that enhances virtual heart simulations by accurately representing complex signals sensed by implantable cardiac devices, improving device validation processes.

Contribution

The novel IEGM model captures local and far-field signals, enabling realistic simulation of device sensing behaviors and issues in virtual heart models.

Findings

Successfully reproduces clinically observed sensing problems

Extends virtual heart model capabilities for device validation

Supports unipolar and bipolar sensing configurations

Abstract

Virtual heart models have been proposed to enhance the safety of implantable cardiac devices through closed loop validation. To communicate with a virtual heart, devices have been driven by cardiac signals at specific sites. As a result, only the action potentials of these sites are sensed. However, the real device implanted in the heart will sense a complex combination of near and far-field extracellular potential signals. Therefore many device functions, such as blanking periods and refractory periods, are designed to handle these unexpected signals. To represent these signals, we develop an intracardiac electrogram (IEGM) model as an interface between the virtual heart and the device. The model can capture not only the local excitation but also far-field signals and pacing afterpotentials. Moreover, the sensing controller can specify unipolar or bipolar electrogram (EGM) sensing configurations and introduce various oversensing and undersensing modes. The simulation results show that the model is able to reproduce clinically observed sensing problems, which significantly extends the capabilities of the virtual heart model in the context of device validation.