Uniesienie odcinka ST w odprowadzeniu aVR w przebiegu zawału ściany przedniej, wskazujące na zamknięcie gałęzi przedniej zstępującej lewej tętnicy wieńcowej przed oddaniem gałęzi przegrodowej ST elevation in lead aVR in course of anterior myocardial infarction indicates occlusion of left anterior descending artery proximal to first septal branch

Background: Anterior wall myocardial infarction caused by proximal left anterior descending artery (LAD) occlusion is associated with high mortality rate. Occlusion of the LAD, proximal to the origin of the first septal branch may lead to additional interventricular septum ischemia. The goal of this study was to evaluate the usefulness of the ST segment shifts in leads aVR and V1 in predicting culprit lesion site in LAD with regard to the origin of the first septal branch (S1). Material and methods: We analyzed a cohort of 37 patients, divided into two groups: group A (n = 22) comprised patients with myocardial infarction caused by lesion localized proximal to the origin of the S1 branch, whilst group B (n = 15) comprised patients with occlusion localized distal to the origin of the S1 branch. Results: Both ST segment elevation ≥ 0.5 mm in lead aVR and ST segment elevation ≥ 2 mm in lead V1 were more frequent in group A (45.45% vs. 6.7%, p = 0.012 and 45.45% vs. 13.3%, p = 0.043, respectively). We found ST segment elevation ≥ 0.5 mm in lead aVR as well as ST segment elevation ≥ 2 mm in lead V1 to be a specific markers (93.37%, and 86.67%, respectively) of the localization of the culprit lesion proximal to the origin of the first septal branch. In group A, ST segment elevation in lead aVR was less frequent (23.8% vs. 79.92%, p = 0.014) among patients with large conal branch. Conclusions: ST segment elevation ≥ 0.5 mm in leads aVR and ≥ 2 mm in lead V1 strongly predicts occlusion proximal to the origin of the S1 branch. In patients without ST segment