Moving Dipole Determination From 12-Lead ECGs Can Improve Detection of Acute Myocardial Ischemia

摘要

We investigated the potential clinical utility of a single moving equivalent dipole (MED) constructed from 12-lead ECGs. A set of MEDs representing the heart cycle, with each MED comprised of a location, orientation and amplitude, is derived from a spherically bounded volume conductor model using an inverse algorithm. We hypothesized that ischemia could be more sensitively determined by the change in the instantaneous locations of the MED than by changes in the standard scalar ECG. MED-related data from 103 patients within the STAFF III database who underwent elective coronary artery occlusion (RCA or LCX or LDA) were compared to those from 563 healthy subjects. MED locations and orientations were expressed within the heart's local coordinate system and related to modeled heart wall segments. Significant changes in MED locations and orientation were noted during coronary artery occlusions, most notably in the LCX and RCA arteries, which are often difficult to detect by standard scalar 12-lead ECG. MED-related changes occurred not only in the ST segment, but also at the end of the QRS. Moreover, MED-related changes occurred very early after occlusion and during low ST segment amplitudes on the scalar ECG, potentially aiding detection of ischemia, especially of the inferior wall.