ESTIMATION OF ANTERIOR INFARCT SIZE WITH BODY-SURFACE QRST INTEGRAL MAPS IN THE PRESENCE OF ABNORMAL VENTRICULAR ACTIVATION SEQUENCE IN DOGS

The possibility of estimating infarct size with body surface QRST integral (I(QRST)) maps was investigated in dogs. I(QRST) maps were constructed from 87-lead body surface ECGs, which were recorded 1 week after the production of anterior myocardial infarction during artificial pacing that simulated normal conduction, left bundle branch block, and Wolff-Parkinson-White syndrome in 11 dogs. Small differences were observed between the I(QRST) Maps of the normal conduction and left bundle branch block models (r = 0.93, root mean square difference = 8.71 mVmsec) and between the normal conduction and Wolff-Parkinson-White models (r = 0.96, root mean square difference = 6.03 mVmsec). Summation of the QRST integral values over the body surface leads (QRST index) inversely correlated with infarct size in all three conductions models: r = -0.91 (p < 0.001) in the normal conduction model; r = -0.81 (p < 0.001) in the left bundle branch block model; and r = -0.86 (p < 0.001) in the Wolff-Parkinson-White model. These results show that I(QRST) maps permit noninvasive estimation of infarct size, even in the presence of abnormal activation sequences.