Expert ECG Quiz 18 Answer

1. Normal sinus rhythm
2. Premature atrial contractions
3. T wave abnormality - Memory T waves

Memory T wave abnormalities occur when there is a sudden change in ventricular activation. This occurs in the setting of termination of prolonged ventricular pacing, termination of sustained  ventricular tachycardia or when a rate dependent bundle block terminates and changes back to a narrow complex. The T wave inversions are asymmetric helping to distinguish from ischemia. They are transient and eventually return to normal. This ECG was from a patient with a pacemaker who was not pacing during this tracing, but the memory T waves were present.

Related Topic Reviews: Premature Atrial Contractions