Prediction of left ventricular systolic dysfunction in left bundle branch block using a fine-tuned ECG foundation

Do Heon Kim1, Youngnam Bok2, Sun Hwa Lee3,4

  • 1Chungnam National University College of Medicine, Daejeon, Republic of Korea.

Scientific Reports
|January 16, 2026
PubMed

Insights

A new AI model fine-tuned on ECG data improves detection of left ventricular systolic dysfunction in patients with left bundle branch block. This AI tool offers a promising alternative when echocardiography is not immediately available, aiding early diagnosis and patient management.

Area of Science:

  • Cardiology
  • Artificial Intelligence
  • Medical Diagnostics

Background:

  • Left bundle branch block (LBBB) is a significant ECG finding associated with left ventricular systolic dysfunction (LVSD).
  • Early detection of LVSD is critical for patient outcomes, but echocardiography is not always readily accessible.
  • Standard diagnostic methods for LVSD can be time-consuming and may not be immediately available in all clinical settings.

Purpose of the Study:

  • To develop and evaluate a fine-tuned ECG foundation model (FM) for enhanced LVSD detection in LBBB patients.
  • To compare the performance of the proposed ECG-FM against conventional deep learning models.
  • To identify key ECG features predictive of LVSD in LBBB patients using explainability techniques.

Main Methods:

  • Retrospective multicenter analysis of 2,031 paired ECG-echocardiographic datasets from 892 LBBB patients.
  • Fine-tuning a pre-existing ECG foundation model for LVSD prediction.
  • Comparison with baseline deep learning models: Fully Convolutional Network (FCN), LSTM-FCN, ResNet, and InceptionTime.
  • Utilized DeepLIFT analysis for feature importance assessment.

Main Results:

  • The fine-tuned ECG-FM achieved an accuracy of 0.758, sensitivity of 0.771, and AUROC of 0.807, outperforming baseline models.
  • Sequential partial fine-tuning yielded the highest sensitivity (0.787), enhancing screening capabilities.
  • DeepLIFT analysis highlighted QRS complex and T wave features in leads V1-V4 as crucial predictive factors.

Conclusions:

  • The fine-tuned ECG-FM significantly improves LVSD detection in LBBB patients.
  • This AI-driven approach offers potential for earlier clinical diagnosis when echocardiography is unavailable.
  • The model's ability to identify critical ECG features may enhance clinical management and improve patient outcomes.

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