Prospective Evaluation of AI-ECG for SHD Detection

12-lead ECG investigation is a standard, non-invasive diagnostic procedure used as an intervention to assess participants' cardiac electrical activity. For the purposes of this study, 12-lead ECGs will be collected for the application of AI-ECG models for the detection of HF, VHD, and/or PH and will not be used to inform or alter patients' standard NHS care.

Single-lead ECG taken using an Apple Watch Series 4 is a non-invasive, participant-initiated recording of cardiac electrical activity through a wearable device. While more limited than a 12-lead ECG, it can capture rhythm abnormalities-such as atrial fibrillation-and offers a convenient method for remote or continuous heart monitoring during the study. For the purposes of this study, single-lead ECGs will be collected for the application of AI-ECG models for the detection of HF, VHD, and/or PH and will not be used to inform or alter patients' standard NHS care.

Three-lead ECG recorded using the Eko CORE 500 digital stethoscope is a non-invasive, clinician-operated cardiac assessment tool that captures real-time electrical activity of the heart during auscultation. It provides enhanced diagnostic information compared to single-lead recordings, allowing detection of arrhythmias and signs of structural heart disease at the point of care, supporting integrated clinical and digital assessment. For the purposes of this study, 3-lead ECGs will be collected for the application of AI-ECG models for the detection of HF, VHD, and/or PH and will not be used to inform or alter patients' standard NHS care.

A single- or 6-lead ECG recorded using the AliveCor KardiaMobile 6L device which is a portable, non-invasive method for capturing cardiac electrical activity. Operated by the participant or clinician, the device enables rapid rhythm assessment and detection of abnormalities such as atrial fibrillation. The 6-lead configuration offers more comprehensive data than single-lead recordings, supporting enhanced arrhythmia and conduction analysis in both in-clinic and remote settings. For the purposes of this study, single- and 6-lead ECGs will be collected for the application of AI-ECG models for the detection of HF, VHD, and/or PH and will not be used to inform or alter patients' standard NHS care.

A minimally invasive biomarker assessment used to evaluate cardiac wall stress and function. Elevated levels can indicate the presence or severity of heart failure and other forms of structural heart disease, making it a valuable tool for diagnosis, risk stratification, and monitoring of cardiac status throughout the study period. For the purposes of this study, NT-proBNP will be collected to assess its accuracy at detecting HF, PH, and VHD with comparison with AI-ECG detections. The investigators will also evaluate the accuracy of AI-ECG detections combined with NT-pro-BNP, for detecting HF, VHD, and PH. The investigators will not be using NT-proBNP results to inform or alter patients' standard NHS care.