abstract

presented

at the 1995 ACC

New Orleans, Louisiana

March 20-22, 1995

Surface Laplacian ECG Maps Provide a Sensitive and Localizing Measure of Cardiac Ischemia

J Am Coll Cardio Feb. 1995; Special Issue: 961-80

David E. Leeman, Samuel J. Shubrooks, *Kevin S. Librett, *Paul E. Grimshaw, *Richard J. Cohen, Deaconess Hospital, Boston, MA, Massachusetts Institute of Technology, Cambridge, MA.

To test the hypothesis that Laplacian surface electrocardiography provides a sensitive and local measure of coronary ischemia, we studied six consecutive patients undergoing balloon angioplasty. Three self-adhesive pads of electrodes containing 84 multipolar Laplacian electrodes were applied to the anterior and left-lateral thorax. Laplacian electrograms and a standard 12 lead ECG were recorded prior to and during each balloon inflation. The ratio of ST segment shift to baseline QRS amplitude (ST/Q) was computed for the Laplacian electrodes and the standard 12 leads. Defining ST/Q=0.1 to be the minimum significant ST shift, Laplacian maps in all six patients revealed a significant ST shift during balloon inflation while the 12 lead ECG revealed a significant ST shift in only three patients. The mean peak value of ST/Q in the Laplacian maps was 0.40 versus 0.13 in the 12 lead ECG (p=0.01). Laplacian maps of ST/Q showed localized elevation over the expected region of distribution of the occluded vessel, often surrounded by a region of negative ST/Q. The unipolar leads revealed a diffuse bipolar pattern of ST segment shift. Conclusion: Body surface Laplacian mapping may provide a sensitive and accurate noninvasive means of detecting and localizing cardiac ischemia, superior to the 123 lead ECG.

Laplacian ST/Q map during distal left anterior descending coronary artery occlusion.

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