Inverted T waves produced by myocardial ischemia are classically narrow and symmetric. T-wave inversion (TWI) associated with an acute coronary syndrome (ACS) is morphologically characterized by an isoelectric ST segment that is usually bowed upward (ie, concave) and followed by a sharp symmetric downstroke. The terms coronary T wave and coved T wave have been used to describe these ischemic TWIs. Prominent, deeply inverted, and widely splayed T waves are more characteristic of non-ACS conditions such as juvenile T-wave patterns, left ventricular hypertrophy, acute myocarditis, Wolff-Parkinson-White syndrome, acute pulmonary embolism, cerebrovascular accident, bundle branch block, and later stages of pericarditis. (Am J Emerg Med 2002;20:252-262.