Transient Giant R Wave as a Marker for Ischemia in Unstable Angina.

Unstable angina is a clinical diagnosis that may present with or without electrocardiographic changes. The "giant R wave" on electrocardiogram has been reported as a manifestation of acute ischemia; however, it is a rare finding in current clinical practice. We describe a case of a patient with unstable angina and a transient "giant R wave" pattern with a culprit lesion in the right coronary artery.