Electrocardiographic detection and quantification of acute myocardial ischemia with dipole modeling

Clinical electrocardiography is based on concept of a dipolar cardiac generator. This concept is not commonly used in quantitative analysis of the electrocardiograms (ECG). We applied dipole modeling and numerical field calculation in the detection of acute myocardial ischemia and for estimating the size of the resulting infarction. Our data set consisted of 79 acutely ischemic patients and 84 controls. Dipoles were fitted to various ECG markers linearly derived from body surface potential mapping data. The best discriminating dipole parameter was sought in a leave-one-out manner. Size estimation was done by correlating the dipole parameters with CK-MB mass. With the 12-lead ECG electrode layout, ST integral was the best marker in the whole patient set, and T integral in patients with myocardial infarction. In these both cases, the cosine of the sagittal angle was the best discriminating parameter. These parameters clearly outperformed the conventional ECG criteria in detection of ischemia.