Fig. 6: XAI relevances for leads V1 and V4 indicating the decision-making of the AI-ECG.

The relevance values are normalized between −1 and 1 and aligned by the detected R peaks (dashed line) to obtain an average relevance over all subjects and heartbeats. Standard ECG parameters such as P-wave or QRS-complex are defined via physiological boundaries. Positive relevances indicating more pronounced aging effects resulting in a higher age prediction whereas negative relevances result in the prediction of younger age.