Paul Grimshaw

961-80 Surface Laplacian ECG Maps Provide a Sensitive and Localizing Measure of Cardiac Ischemia

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 ORS amplitude (ST/O) was computed for the Laplacian electrodes and the standard 12 leads. Defining ST/O = 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 5T shift in only three patients. The mean peak value of ST/O in the Laplacian maps was 0.40 versus 0.13 in the 12 lead ECG (p = 0.01). Laplacian maps of ST/O showed localized elevation over the expected region of distribution of the occluded vessel, often surrounded by a region of negative ST/O. 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 12 lead ECG. Download high-res image (105KB) Download full-size image Laplacian ST/O map during distal left anterior descending coronary artery occlusion.