Using multi-channel intracavity ECGs in a cross-validation procedure to estimate myocardial infarction

The objective of this study was to evaluate the ability of intracavity electrocardiograms (ECGs) to determine the presence of acute myocardial infarction in canines. Intracavity potentials were obtained from a cylindrical probe, 45 mm×10 mm in size, introduced into the left ventricular cavity through the left atrium. The probe has 40 evenly spaced unipolar electrodes on its surface. Intracavity potentials were recorded before and after myocardial infarction in six dogs. Evaluation of 480 normal and 480 post-infarct intracavity waveforms was based on the QRS area, ST segment area, maximum potential, and maximum negative dV/dt. Maximum negative dV/dt, the best one-dimensional classifier, was combined with each of the other three variables in a two-dimensional cross-validation procedure. Maximum negative dV/dt and maximum potential correctly identified 86% of the normal recordings and 87% of the post-infarct recordings. Maximum negative dV/dt and QRS areas classified 84% of the normal and 82% of the post-infarct waveforms correctly. Maximum negative dV/dt and ST segment area correctly identified 85% and 82% of the normal and post-infarct recordings, respectively