CDC Analysis Preprocessed Beat Data

Beat-level cardiac duty cycle (CDC = RT/RR) measurements from seven publicly available ECG databases, spanning ~250,000 subjects.Data from LUDB, QTDB, PTB Diagnostic, PTB-XL, Fantasia, Autonomic Aging, and CODE-15%. Each beat-level CSV follows a unified 14-column format recording R-peak, T-end, and next R-peak sample numbers alongside subject demographics, clinical group assignment, and annotation provenance. The CODE-15% clinical metadata (including all-cause mortality follow-up) is provided separately. No quality filters are applied during export; all filtering is deferred to the analysis stage for transparency. See the README for full column definitions, annotation tier descriptions, and usage instructions. This dataset accompanies Froese et al. (2026), "The cardiac duty cycle maintains an optimal ratio (1/e) in healthy aging," submitted to Communications Medicine.