Registry Study for the Evaluation of High-risk Cardiac Patients by WILLEM AI-based ECG Platform

Inclusion Criteria: * EC/IRB approval of ICF waiver prior to recruitment; otherwise, signed informed consent form by subject and investigator * Age \> 18 years-old, with no upper limit * Subjects undergoing standard of care electrocardiogram (ECG) of any duration from any hardware device * All available, but at least one, legible ECG tracings in raw data format (e.g. DICOM, XML, EDF, JSON, HL7, SCP, WFDB, CSV, etc.) * Available subject clinical data associated with the ECG * For 12-lead ECGs, a minimum length of 10 seconds at a minimum sample frequency of 250 Hz * For ECGs from Holters, wearables, patches, insertable cardiac monitors, telemetries, etc., a minimum length of 30 seconds at a minimum sample frequency of 200 Hz with a lead I / II or its MCL-DII lead approximation * For prospective eligibility only: * Signed informed consent form, unless previously waived by the EC/IRB * Site technical viability for ECG and subject clinical data transfer (e.g. end-to-end integration following interoperability standards such as FHIR, HL7 or DICOM) Exclusion Criteria: * Unavailable or suboptimal quality of the raw data from the ECG signal * Age \< 18 years-old