Arrhythmias & electrophysiologyCohort study

Identifying the Presence and Characteristics of Mid-Myocardial and Epicardial Fibrosis From Intracardiac Electrograms in Patients Undergoing Ventricular Arrhythmia Ablation Using a Transformer-Based Self-Supervised Classifier

Circ Arrhythm ElectrophysiolPublished

  • retrospective study
  • stratified patient-wise split

Authors' conclusion

Our study demonstrates that routine intracardiac electrograms enable the identification of endocardial, mid-myocardial, and epicardial scar using a transformer-based self-supervised deep learning model. Ultimately, our model has the potential to provide magnetic resonance imaging-like fibrosis maps during EP procedures without the need for external imaging and to increase the data set size for patient-specific models in ventricular arrhythmia research.

Study context

Population
Patients undergoing ventricular arrhythmia ablationpatients, 131,584 cardiac contact electrogram (EGM) signals · training/validation set 37 · testing set 9
Participants
46 patients
Exposure
EGM2Scar-AI vs basic convolutional neural network models, with scar labels from coregistered cardiac magnetic resonance imaging and electroanatomic mapping surface meshes

Main finding

As reported in the abstract

Average task-specific area under the receiver operating characteristic curve across all 3 scar types

basic convolutional neural network

0.729 (0.725-0.732)

average area under the receiver operating characteristic curve

short-time Fourier transform-based convolutional neural network

0.729 (0.726-0.733)

average area under the receiver operating characteristic curve

EGM2Scar-AI

0.822 (0.819-0.825)

average area under the receiver operating characteristic curve

Observational data: associations, not effects.

Further findings

Performance by scar type

All models performed better on endocardial and mid-myocardial fibrosis identification, with a modest reduction in performance for epicardial fibrosis

Sensitivity and specificity

Sensitivity improved significantly with the transformer-based architecture without appreciable changes in specificity

Original publication

Identifying the Presence and Characteristics of Mid-Myocardial and Epicardial Fibrosis From Intracardiac Electrograms in Patients Undergoing Ventricular Arrhythmia Ablation Using a Transformer-Based Self-Supervised Classifier. Circ Arrhythm Electrophysiol. Published 7 July 2026. doi:10.1161/circep.125.014765

Summarised from the published abstract; every number is checked against it