Possible annotation misalignment 07162 (similar to record 07859) in MIT-BIH AFDB

Dataset Issue Report

Dataset

MIT-BIH Atrial Fibrillation Database (AFDB)

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Summary

I observed a potential annotation misalignment issue in one of the records that appears similar to the previously reported problem in record 07859, where missing samples caused offset between ECG signals and QRS annotations.

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Affected Record

• Record ID: 07162
• Files: .qrs

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Description of Issue

• The QRS annotations do not align with the visible QRS complexes in the ECG waveform.
• The misalignment appears consistent throughout the record.
• The observed offset suggests a possible sample shift or missing samples at the beginning of the signal.

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Similar Known Issue

This behavior resembles the previously documented issue for record 07859, where:

“2569 samples appeared to be missing from the beginning of the record, causing annotation misalignment.”

This raises the possibility that a similar issue may exist in the record reported here.

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Steps to Reproduce

1. Load the record using WFDB (Python or MATLAB), also https://physionet.org/lightwave/
2. Plot ECG waveform together with QRS annotations
3. Observe consistent offset between annotations and QRS complexes

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Additional Notes

• The issue is reproducible across multiple visualizations

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Request

Could you please verify:

• Whether any samples are missing or misaligned in this record, and
• Whether the annotation file needs correction or re-alignment

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Thank you for maintaining this valuable dataset and for your support.

Best regards
Md Shariful Alam

Start with record 07162 and its .qrs annotation file, loading the record with WFDB and using the linked Lightwave view to plot the ECG with its QRS annotations. Compare the observed offset with record 07859 and determine whether samples are missing or the annotation file is misaligned; done means the record is verified and any needed annotation correction is documented.