Clinical significance of the disappearance of septal Q waves after the onset of myocardial infarction - Correlation with location of responsible coronary lesions

We investigated the relationship between the disappearance of septal Q wave s after myocardial infarction (MI) and the location of the culprit lesion. We studied 82 patients following their first anteroseptal MI who had an ele ctrocardiogram performed before the MI. Septal Q waves were detectable befo re MI in 56 patients and disappeared after MI in 17 of those patients. The culprit lesion was located proximal to the origin of the first septal branc h (S1) in 13 patients (76%). Disappearance of septal Q waves following MI p redicted that the culprit lesion was proximal to the origin of S1 (sensitiv ity, 42%; specificity, 84%; predictive value, 76%; and accuracy, 61%). If s eptal Q waves that were detected before MI disappeared after MI, the culpri t lesion was located proximal to the origin of S1 in 76% of the patients. T his finding may be clinically useful in caring for patients following MI.