The patient was treated for unstable angina with aspirin, β-blocker, high-dose statin, and anticoagulated with heparin overnight; thienopyridine was not administered. Serial cardiac biomarkers were negative and follow-up ECG showed resolution of all ST-segment abnormalities. The following morning, he underwent a Bruce protocol exercise treadmill test. After 4 minutes and at a work load of 5.8 metabolic equivalents, the patient quickly became pale and dyspneic with anterior chest pain, and his ECG evolved to 3-mm ST-segment elevation in lead aVR, submillimeter ST-segment elevation in lead V1, 2-mm ST-segment elevation in lead aVL, and 3- to 5-mm downsloping ST-segment depressions in leads II, III, aVF, and V3 through V6. His heart rate rapidly dropped from sinus tachycardia at 117 beats/min to sinus bradycardia at 44 beats/min, with nadir blood pressure of 42/22 mm Hg without syncope. The patient was resuscitated with intravenous fluid and transferred to a tertiary care center for urgent cardiac catheterization.