T-wave inversion: cardiac memory or myocardial ischemia?

This article presents a case report of a 74-year-old man with T-wave inversion (TwI) in atrial fibrillation noted during routine pacemaker interrogation. The patient was seen for routine pacemaker interrogation, at which time he was noted to have underlying atrial fibrillation. A12-lead electrocardiogram of the atrial fibrillation revealed significant TwIs. He was subsequently worked up for myocardial ischemia and was found to have a moderate-sized,moderate-degree inferior wall myocardial perfusion defect. He was subsequently referred for a cardiac catheterization. The cardiac catheterization revealed nonobstructive coronary artery disease. The follow-up electrocardiogram revealed persistent but attenuated TwI.The TwIs were attributed to cardiac memory, a common but infrequently recognized phenomenon of which many clinical practitioners are unaware. Cardiac memory is due to the T wave tracking the preceding abnormal QRS complex and can be induced by right ventricular pacing or arrhythmias.