TCTMD -- Over one quarter of patients with isolated anterior ST-segment depression on electrocardiogram (ECG) may require urgent cardiac catheterization, even though they are not suffering the classic signs of ST-segment elevation myocardial infarction (STEMI), according to a study in the August 2010 issue of JACC: Cardiovascular Interventions. In the study, less than 5% of patients with an occluded culprit artery were correctly identified and sent for urgent angiography.