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Main Authors: Li, Haitao, Liu, Che, Ding, Zhengyao, Liu, Ziyi, Shao, Wenqi, Huang, Zhengxing
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2505.11939
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author Li, Haitao
Liu, Che
Ding, Zhengyao
Liu, Ziyi
Shao, Wenqi
Huang, Zhengxing
author_facet Li, Haitao
Liu, Che
Ding, Zhengyao
Liu, Ziyi
Shao, Wenqi
Huang, Zhengxing
contents Electrocardiograms (ECGs) are essential for diagnosing cardiovascular diseases. However, existing ECG-Report contrastive learning methods focus on whole-ECG and report alignment, missing the link between local ECG features and individual report tags. In this paper, we propose FG-CLEP (Fine-Grained Contrastive Language ECG Pre-training), which achieves fine-grained alignment between specific ECG segments and each tag in the report via tag-specific ECG representations. Furthermore, we found that nearly 55\% of ECG reports in the MIMIC-ECG training dataset lack detailed waveform features, which hinders fine-grained alignment. To address this, we introduce a coarse-to-fine training process that leverages large language models (LLMs) to recover these missing waveform features and validate the LLM outputs using a coarse model. Additionally, fine-grained alignment at the tag level, rather than at the report level, exacerbates the false negative problem, as different reports may share common tags. To mitigate this, we introduce a semantic similarity matrix to guide the model in identifying and correcting false negatives. Experiments on six datasets demonstrate that FG-CLEP significantly improves fine-grained alignment, outperforming state-of-the-art methods in both zero-shot prediction and linear probing. Meanwhile, the fine-grained reports we generate also enhance the performance of other methods.
format Preprint
id arxiv_https___arxiv_org_abs_2505_11939
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publishDate 2025
record_format arxiv
spellingShingle Fine-grained Contrastive Learning for ECG-Report Alignment with Waveform Enhancement
Li, Haitao
Liu, Che
Ding, Zhengyao
Liu, Ziyi
Shao, Wenqi
Huang, Zhengxing
Signal Processing
Artificial Intelligence
Machine Learning
Electrocardiograms (ECGs) are essential for diagnosing cardiovascular diseases. However, existing ECG-Report contrastive learning methods focus on whole-ECG and report alignment, missing the link between local ECG features and individual report tags. In this paper, we propose FG-CLEP (Fine-Grained Contrastive Language ECG Pre-training), which achieves fine-grained alignment between specific ECG segments and each tag in the report via tag-specific ECG representations. Furthermore, we found that nearly 55\% of ECG reports in the MIMIC-ECG training dataset lack detailed waveform features, which hinders fine-grained alignment. To address this, we introduce a coarse-to-fine training process that leverages large language models (LLMs) to recover these missing waveform features and validate the LLM outputs using a coarse model. Additionally, fine-grained alignment at the tag level, rather than at the report level, exacerbates the false negative problem, as different reports may share common tags. To mitigate this, we introduce a semantic similarity matrix to guide the model in identifying and correcting false negatives. Experiments on six datasets demonstrate that FG-CLEP significantly improves fine-grained alignment, outperforming state-of-the-art methods in both zero-shot prediction and linear probing. Meanwhile, the fine-grained reports we generate also enhance the performance of other methods.
title Fine-grained Contrastive Learning for ECG-Report Alignment with Waveform Enhancement
topic Signal Processing
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2505.11939