S. Premaratne et al., ACUTE EPICARDIAL ECG PARAMETERS AS QUANTITATIVE PREDICTORS OF INFARCTSIZE AT 1 WEEK IN THE BABOON, The Journal of surgical research, 70(2), 1997, pp. 101-106
We describe an experimental baboon model that allows quantitative pred
iction of myocardial necrosis measured at 1 week from acute epicardial
ECG parameters recorded from a high-resolution matrix of fixed epicar
dial electrodes, The electrode grid overlies a circumscribed area of u
ltimate necrosis, produced by the occlusion of a selected diagonal bra
nch of the left anterior descending coronary artery (LAD). This grid a
llowed examination of the pattern of changes in ST segment elevation (
ST up arrow) throughout their return to control levels, and profiled c
hanges in the distribution of electrodes recording TQ-ST segment defle
ctions. Those points more centrally located within the area of ST up a
rrow consistently showed greater absolute values of ST up arrow and re
mained elevated longer than the more peripheral electrodes. Areas of t
he electrode matrix corresponding to those electrode points showing si
gnificant ST up arrow (2 mV above control) at each recording interval
through 8 hr were fitted to the area of necrosis underlying this elect
rode grid. While the maximum area of ST up arrow (maxAst) uniformly ov
erestimated infarct size between animals on the order of 25%, regressi
on analysis allowed prediction of the extent of infarct from maxAst wi
th an error of only 5%. Correlation of maxAst with the epicardial exte
nt of infarct, total weight, and volume yielded coefficients of 0.95,
0.85, and 0.91 respectively, while mean ST up arrow (ST up arrow) show
ed a poorer correlation with respective coefficients of 0.49, 0.55, an
d 0.39, MaxAst proved to be the single best predictor of infarct size
assessed at 1 week. (C) 1997 Academic Press.