Data Sources & Acknowledgments

Last updated: August 9, 2026

1. Real ECG Data Source

The real cardiac rhythm data presented in this Service is sourced from the PhysioNet ECG Arrhythmia Database, a large-scale 12-lead electrocardiogram database for arrhythmia study (version 1.0.0).

This database contains 45,152 patient ECG recordings with a 500 Hz sampling rate, featuring multiple common rhythms and cardiovascular conditions labeled by professional experts.

Of those recordings, 45,046 are available in this Service. The remainder are excluded during our processing because their signal data does not pass our validation checks or cannot be reconstructed into a renderable waveform.

2. Citation Requirements

When referencing the real ECG data, the following citations apply:

Primary Citation

Zheng, J., Guo, H., & Chu, H. (2022). A large scale 12-lead electrocardiogram database for arrhythmia study (version 1.0.0). PhysioNet. RRID:SCR_007345. https://doi.org/10.13026/wgex-er52

Original Publication

Zheng, J., Chu, H., Struppa, D., Zhang, J., Yacoub, S.M., El-Askary, H., Chang, A., Ehwerhemuepha, L., Abudayyeh, I., Barrett, A.S., Fu, G., Yao, H., Li, D., Guo, H., & Rakovski, C. (2020). Optimal Multi-Stage Arrhythmia Classification Approach. Scientific Reports, 10.

PhysioNet Standard Citation

Goldberger, A., Amaral, L., Glass, L., Hausdorff, J., Ivanov, P. C., Mark, R., … & Stanley, H. E. (2000). PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals. Circulation [Online]. 101 (23), pp. e215-e220. RRID:SCR_007345.

3. Data License

The PhysioNet ECG Arrhythmia Database is available under the Creative Commons Attribution 4.0 International Public License (CC BY 4.0). Our use of this data complies with the terms of this license.

4. Third-Party Content, Images, and Attribution

The Service may also include third-party educational content, excerpts, images, diagrams, or related materials used under Creative Commons licenses, other open licenses, direct permission, or other lawful bases for use. We make a best effort to provide attribution where required. If you believe attribution is missing, inaccurate, or incomplete, please contact us so we can review and correct the issue.

5. Synthetic Rhythm Data

In addition to the real ECG data, the Service features synthetic (manually created) cardiac rhythms. These rhythms are designed by our team to be directionally accurate educational representations of real cardiac conditions. They are not derived from real patient data and are intended solely for educational illustration purposes.

Synthetic rhythms may differ from actual clinical ECG readings in morphology, timing, amplitude, and other characteristics. They should be used as learning aids only, not as clinical references.

6. AI-Assisted Educational Content

Educational articles and learning materials on this Service may be generated or revised with the assistance of artificial intelligence (AI). These materials may contain errors, omissions, oversimplifications, or outdated statements and should not be treated as authoritative clinical guidance. They have not been validated as a medical device output or as licensed professional advice. Users should verify information against authoritative medical textbooks, peer-reviewed sources, and qualified healthcare professionals.

7. Best-Effort Accuracy and Currency

We make a best effort to present source materials faithfully and keep citations and attributions current. Even so, source catalogs, license terms, educational interpretations, and clinical conventions may change over time. We do not guarantee that every page reflects the most current medical, legal, or licensing position at all times.

8. Requesting Manipulated Data

If you require access to any manipulated or derived data based on the PhysioNet ECG Arrhythmia Database that we use in the Service, you may request this by contacting us at:

We will review such requests and provide data where feasible and permitted by the original data license.

9. Disclaimer

ShadeTree.IT LLC has made a best effort to accurately represent and present the data from PhysioNet and other sources. However, we do not guarantee the accuracy, completeness, licensing status, attribution completeness, or clinical validity of any data or content presented on the Service. All such material is provided for educational purposes only and should not be used for clinical decision-making.

10. Contact

For questions about our data sources or to request access to derived data, please contact:

ShadeTree.IT LLC
Email: support@cardiacrhythmsim.com