European ST-T Database

Data Description

The European ST-T Database is intended to be used for evaluation of algorithms for analysis of ST and T-wave changes. This database consists of 90 annotated excerpts of ambulatory ECG recordings from 79 subjects. The subjects were 70 men aged 30 to 84, and 8 women aged 55 to 71. (Information is missing for one subject. Records e0118-e0122 come from the same subject; also records e0123-e0126, records e0129 and e0133, records e0136 and e0139, records e0147 and e0148, records e0154 and e0155, and records e0162 and e0163.) Myocardial ischemia was diagnosed or suspected for each subject (see reference 1); additional selection criteria were established in order to obtain a representative selection of ECG abnormalities in the database, including baseline ST segment displacement resulting from conditions such as hypertension, ventricular dyskinesia, and effects of medication. The database includes 367 episodes of ST segment change, and 401 episodes of T-wave change, with durations ranging from 30 seconds to several minutes, and peak displacements ranging from 100 microvolts to more than one millivolt. In addition, 11 episodes of axis shift resulting in apparent ST change, and 10 episodes of axis shift resulting in apparent T-wave change, have been marked. Compact clinical reports document each record. These reports, contained within the header (.hea) files associated with each record, summarize pathology, medications, electrolyte imbalance, and techical information about each recording.

Each record is two hours in duration and contains two signals, each sampled at 250 samples per second with 12-bit resolution over a nominal 20 millivolt input range. The sample values were rescaled after digitization with reference to calibration signals in the original analog recordings, in order to obtain a uniform scale of 200 ADC units per millivolt for all signals. (The calibration signals are not included in the signal files.) The header files include information about the leads used, the patient's age, sex, and medications, the clinical findings, and the recording equipment. Each of the signal files is 5,400,000 bytes long.

Two cardiologists worked independently to annotate each record beat-by-beat and for changes in ST segment and T-wave morphology, rhythm, and signal quality. ST segment and T-wave changes were identified in both leads (using predefined criteria which were applied uniformily in all cases), and their onsets, extrema, and ends were annotated. Annotations made by the two cardiologists were compared, disagreements were resolved by the coordinating group in Pisa (see reference 3), and the reference annotation files were prepared; altogether, these files contain 802,866 annotations. A detailed description of the annotations may be found here.

Over half (48 of 90 complete records, and reference annotation files for all records) of this database was contributed to PhysioNet in 2000, and the remainder was contributed in November 2009. A list of all 90 record names is available here.

Acknowledgements

We thank Carlo Marchesi, Alessandro Taddei, and Michele Emdin of the CNR Institute for Clinical Physiology in Pisa for arranging for these recordings to be made available via PhysioNet. Our thanks also to Maarten L. Simoons, Simon Meij, and Johan H.C. Reiber, and to the European Society of Cardiology and its Working Group "Computers in Cardiology", for their support.

Completion of the European ST-T Database was made possible by the European Society of Cardiology. We also thank the many contributors whose efforts supported the creation of the Database.

Additional References

1. Taddei, A., Benassi, A., Biagini, A., Bongiorni, M.G., Contini, C., Distante, G., Landucci, L., Mazzei, M.G., Pisani, P., Roggero, N., Varanini, M., Marchesi, C. ST-T change analysis in ECG ambulatory monitoring: a European standard for performance evaluation. Computers in Cardiology 14:63-68 (1987).
2. Marchesi, C. The European Community concerted action on Ambulatory Monitoring. Journal of Med. Eng. and Techn. 10:131-134 (1986).
3. Taddei, A., Biagini, A., Distante, G., Marchesi, C., Mazzei, M.G., Pisani, P., Roggero, N., Zeelenberg, C. An annotated database aimed at performance evaluation of algorithms for ST-T change analysis. Computers in Cardiology 16:117-120 (1989).
4. ANSI-AAMI EC38:1998 [American National Standard]. Ambulatory electrocardiographs. Association for the Advancement of Medical Instrumentation, 3330 Washington Boulevard, Suite 400, Arlington, VA 22201-4598, USA (1998).
5. ANSI-AAMI EC57:1998 [American National Standard]. Testing and reporting performance results of cardiac rhythm and ST segment measurement algorithms. Association for the Advancement of Medical Instrumentation, 3330 Washington Boulevard, Suite 400, Arlington, VA 22201-4598, USA (1998).