Posttachycardia T-wave changes. A 25-year-old previously healthy man presented to the emergency department with a tachydysrhythmia. After pharmacological intervention, the patient's rhythm converted to normal sinus and symmetrically inverted T-wave changes were noted. Although asymptomatic after conversion, the patient was admitted to the hospital and monitored for two days to rule out cardiac ischemia correlating with the T-wave changes. The patient was ultimately discharged in good health. A review of the emergency medical literature fails to reveal examples of post-tachycardic T-wave changes that may simulate myocardial ischemia but be of no clinical significance. 