Atypical location of ST elevation acute myocardial infarction in relation to the electrocardiogram

Abstract

Introduction. Electrocardiography is an initial non-invasive diagnostic algorithm for ST elevation acute myocardial infarction. Specific electrocardiographic phenomenon is described, when the occlusion of the proximal segment of the right coronary artery or the isolated occlusion of its ventricular branch is presented with ST elevation in the precordial leads. Case Report. A 78-year-old woman was admitted as an emergency due to chest pain and electrocardiographically recorded concave elevation in leads V1 - V3. She was diagnosed with ST elevation myocardial infarction of the anterior region and sent to catheterization laboratory for emergency coronary angiography. It showed an occlusion of the proximal-medial right coronary artery. Behind the occlusion, the right coronary artery, posterior descending artery and posterior lateral artery, a hetero-collateral circulation was seen. Two drug-eluting stents were implanted into the proximal segment of the right coronary artery. Discussion. The phenomenon of acute myocardial infarction caused by occlusion of the proximal right coronary artery and/or ventricular branches of the right coronary artery, presenting with ST segment elevation in the precordial leads, is a consequence of several anatomical variations: occlusion of nondominant right coronary artery, isolated occlusion of the ventricular branch of the right coronary artery, and the occlusion of the right coronary artery proximal to the ventricular branch with hetero collateral circulation on the periphery of the right coronary artery, like in our case. Electrocardiographic characteristic pointing to the occlusion of the proximal right coronary artery and/or ventricular branches of the right coronary artery is higher ST elevation in the lead V1 than in the other leads, followed by the absence of Q wave development. This ST elevation is concave. Conclusion. It is necessary to emphasize the significance of differential diagnosis of culprit lesion in patients with chest pain and elevation of the ST segment in the precordial leads having in mind further different thera peutic algorithms. Patients with right ventricular myo cardial infarction need to maintain an adequate ?preload? and avoid vasodilators in order to maintain the right ventricular stroke volume.