Electrocardiographic findings in ST-segment elevation acute myocardial infarction do not always evolve in a typical manner, with concomitant changes such as early repolarization that can cause diagnostic confusion. We present the case of a patient with typical chest pain and an atypical electrocardiogram, in which the presence of early repolarization in the inferior leads caused subtle changes in the precordial leads to be overlooked, leading to an error in the initial diagnosis but not in the treatment.

Atrial fibrillation (AF) can produce embolism and remains as an important cause of morbidity and mortality. We report the case of a patient admitted with a history of palpitations and oppressive retro sternal pain. AF was found associated with ECG changes compatible with acute myocardial infarction. Biomarkers (Troponin T and CK-MB) and motility disorders assessed by echocardiography confirmed diagnosis and coronary angiography was performed. A total occlusion of posterior ventricular coronary artery branch was found, which was successfully treated with thrombus aspiration, reestablishing coronary flow. While AF can be commonly associated with acute myocardial infarction, thromboembolism secondary to AF producing total coronary occlusion is rare. This clinical scenario should be considered before stenting.