 Myoglobin is a sensitive marker for muscle injury, making it a potential marker for heart attack in patients with chest pain.However, elevated myoglobin has low specificity for acute myocardial infarction (AMI) and thus CK-MB, cardiac Troponin, ECG, and clinical signs should be taken into account to make the diagnosis.Myoglobin belongs to the globin superfamily of proteins, and as with other globins, consists of eight alpha helices connected by loops.