Coefficients for the Derivation of an ST Sensitive Patch Based Lead System from the 12 Lead Electrocardiogram

Background: There are limited datasets available to facilitate the evaluation of patch-based lead systems, so the leads must be derived from existing data, mainly the 12-lead ECG. We have previously introduced a short spaced lead (SSL) system consisting of two leads with the largest ST segment changes during ischaemic-type episodes. In this study, we aim to evaluate the derivation of this patch-based lead system from the 12-lead ECG. Method: Thoracic body surface potential maps (BSPM) were recorded from $n=734$ patients. Using Laplacian interpolation, each recording was expanded to the 352-node Dalhousie torso. The eight independent channels of the 12-lead ECG were extracted (I, II, V1-V6) with the two leads of the SSL patch Coefficients were derived using linear regression from the 12-lead ECG to the SSL patch. Results: The median Pearson correlation coefficients (CC) and root mean square error (RMSE) for each lead were calculated as follows (CC/RMSE): $0.986/74.3 \mu V$ (ST monitoring lead); $0.976/65.3 \mu V$ (spatially orthogonal lead). Conclusion: We have developed coefficients that allow the derivation of a patch-based lead system from the 12-lead ECG. Given the high correlation, it is possible to generate short spaced lead systems from existing diagnostic lead systems, however, amplitude errors are introduced in the process.