Disappearance of septal q-wave or appearance of abnormal Q-wave in V5 and V6 after onset of anterior acute myocardial infarction： electrocardiographic and angiographic correlations

Background The factors influencing the q-wave changes in V5 and V6 during anterior acute myocardial in- farction （AMI） have not been thoroughly described. Methods We studied 70 patients with a first anterior AMI, in whom the electrocardiogram （ECG） showed either disappearance of the normal septal q wave （n = 24） or presence of pathological Q wave in V5 and V6 （n = 46） during follow-up. The ECG and coronary angiography findings were correlated. Results There was no difference between the 2 groups in the culprit site proximal to S1 （46% vs. 36%, P = 0.405）, but the culprit site was more frequently located proximal to DI in the group with abnormal Q wave （21% vs. 67%, P = 0.001）. Patients with disappearance of the septal q wave more often had a large obtuse marginal branch （46 % vs. 22%, P = 0.037） and disappearance of the r wave in V1 （88% vs. 7%, P = 0.001）. Patients with abnormal Q-wave more often had a large LAD （42% vs. 71%）, small r wave or tall or wide R wave in V1 （0 % vs. 89 %, P = 0.001） and abnormal Q waves in the inferior leads （33% vs. 59%, P = 0.044）. Conclusions In patients with first anterior AMI, q wave changes in V5 and V6 correlated with the morphology in V1. Emerging abnormal Q wave in Vs/V6 predicted the culprit lesion in a large LAD proximal to D1, but disappearance of the septal q wave could not predict the culprit lesion proximal to S1.