Some pitfalls of vectorcardiographic diagnosis of myocardial infarction with particular respect to emphysema

Vectorcardiographic changes indicating old myocardial infarction were observed in eight of 288 patients who at autopsy did not show extensive myocardial disease. Of these eight patients four had been given a misdiagnosis of anteroseptal infarction, while four had been suspected of having anterolateral or anterior infarction on the basis of an abnormal configuration of the initial portion of the QRS loop. The possibility of overdiagnosis of myocardial infarction should be borne in mind in reading vectorcardiograms, especially in the absence of clear-cut history of the condition.

A prominent Q wave simulating anteroseptal or anterior infarction was observed in lead V 2 or V 3 , or in both in 12-lead electrocardiograms in all these eight cases. A high incidence of coronary sclerosis, scattered myocardial fibrosis and pulmonary emphysema was noted in these false positive cases at autopsy, but right ventricular hypertrophy, significant septal hypertrophy, or giant right atrium was not demonstrated.