Session S53.2

Eigen-Vector Based Leads for Reconstruction of the 12-Lead ECG

DD Finlay*, CD Nugent, MP Donnelly

University of Ulster
Belfast, UK

In electrocardiography limited or derived lead systems are currently stimulating much interest. These systems offer the potential to record the ECG from fewer sites than would normally be used. Information from missing sites is then estimated using transformation coefficients.
In the current study we have developed a limited lead system to allow reconstruction of the 12-lead ECG. This has been based upon the analysis of eigen-vectors calculated from body surface potential map (BSPM) data.
Eigen-vectors were calculated from a set of 117 lead BSPMs (normal = 172, LVH = 178, MI = 209). Following calculation the eigen-vectors were ranked based on eigen-values. The extrema of the first three eigen-vectors were used to determine the positions of recording sites for three bipolar leads. These three bipolar leads were then used to reconstruct 12-lead ECGs recorded from an unseen group of subjects (normal = 57, LVH = 59, MI = 69).
It was found that the suggested leads could reconstruct the 12-lead ECG with a median RMS error of 57.0 µV and a correlation coefficient of 0.968. This was in comparison to the EASI leads, which, when tested on the same data, produced a median RMS error of 60.1 µV and a correlation coefficient of 0.955. Following comparison on a lead-by-lead basis the eigen-vector based leads were found to perform particularly well in the reconstruction of the precordial leads V1-V5.
The proposed lead system is based upon the exploitation of statistical orthogonality in BSPM data. Our results have shown that these leads compare favorably with the spatially orthogonal EASI leads. Further work is required to refine and to determine the practical utility of the proposed leads in practice.

(Abstract Control Number: 91)