Coronary angiographic significance of hyperacute ST-T changes associated with regadenoson stress.

An abnormal electrocardiographic stress test is typically characterized by ST segment depression. In rare cases, ST segment elevation is observed, which, in the absence of diagnostic Q waves, has anatomic specificity for localized myocardial ischemia. Most instances of ST elevation occurring during cardiac stress testing have been observed with exercise, with only six cases reported with pharmacologic stress. Despite different physiologic mechanisms for inducing myocardial ischemia, development of ST segment elevation during pharmacologic stress, as illustrated by the present case, may also be indicative of critical coronary stenoses, warranting urgent coronary arteriography.