Noninvasive identification of ischemic lesions in the heart

Abstract

A method for noninvasive identification of heart lesions with changed repolarization caused by local ischemia was proposed and tested on a model and on a group of patients. It evaluates changes in QRST integral maps measured on a chest surface of known geometry and computes an equivalent dipole representing the position, size and orientation of the lesion. Testing on a computer model indicated ability of the method to localize small subendocardial and subepicardial lesions with an error less about 1 cm. From 11 patients with single vessel stenosis mapped before and after the percutaneous cardiac intervention, differences in QRST integral maps could be represented by a dipole in 8 patients. 6 LAD and 1 RCA lesion were identified successfully, localization of 1 RCA lesion failed. Results of the study suggest that difference QRST integral maps can help in identification of small ischemic regions on the epicardial or endocardial surface by estimating parameters of an equivalent dipole characterizing the lesion.