Fallibility of the epicardial electrocardiogram in quantitation of myocardial necrosis

Estimation of infarct size utilising the epicardial electrocardiogram has been the subject of considerable controversy. The present study re-examines this technique in a dog model. It demonstrates that epicardial Q waves and S-T elevation are qualitative markers of local necrosis with different degrees of reliability; neither, however, is quantitatively related in a simple linear fashion to extent of necrosis. Conclusions from previous studies have been influenced both by different mathematical analyses of data and the inclusions of nonhomogenous sites in linear regression models.