A correlative study of postmortem, electrocardiographic, and spatial vectorcardiographic data in myocardial infarction

The spatial vectorcardiograms (sVCG) and electrocardiograms were studied with respect to the gross and microscopic data in 59 instances of myocardial infarction. Besides the early abnormalities in the QRS sÊ-loop frequently associated with the electrocardiographic Q of infarction, there were recognizable alterations in the sVCG associated with the anatomic location of the infarction: lateral wall infarcts shortened vectors in mid-QRS sÊ-loop, and posterior lateral basal infarction altered the terminal portion distinctively. The myocardial lesions included fresh infarcts, solid scars, scattered fibrosis, and scar with interwoven intact muscle fibers. Where many normal-appearing fibers were present in the lesion, the previously recorded ECG or sVCG frequently failed to show the diagnostic signs of infarction. However, by presenting the depolarization complex in greater detail, the sVCG supplemented the ECG, improving the accuracy of diagnosis of infarction, especially among the smaller, less solid lesions.