Abstract：Objective To investigate the characteristics of ST-segment mirror-image change (MC) in electrocardiogram(ECG) among patients with acute myocardial infarction (AMI) complicated by complete right bundle branch block (CRBBB), and their correlation with culprit vessel location. Methods We retrospectively collected 82 patients diagnosed with AMI complicating CRBBB by ECG. They were divided into MC group (55 cases) and non-MC group (27 cases) according to the presence or absence of ST-segment MC.The clinical data and coronary angiography results of the two groups were analyzed. Fifty cases with coronary artery stenosis in the MC group were further divided into two subgroups: the inferior wall AMI group (16 cases) and the anterior wall AMI group (34 cases); the distribution of the infarctionrelated vessels was analyzed. Results The proportion of patients presenting as chest tightness and chest pain lasting no more than 6 hours in the MC group is significantly higher than that in the non-MC group (P<0.01). In the inferior wall AMI patients with ST-segment depression in lead Ⅰ, aVL and V1-V6, those with right coronary lesions account for 90.9% while those with multivessel lesions account for 63.6%. All the anterior wall AMI patients with ST-segment elevation in inferior wall leads have anterior descending branch lesions, and 85.7% of them are multivessel involved. Conclusion The earlier the ECG is recorded after AMI, the higher the incidence of MC. Based on MC, infarctionrelated vessels can be predicted, whether the lesion involves a single vessel or multiple coronary arteries can be determined, and the myocardial infarct size can be assessed.
