[Electrotonic modulation as a differential diagnosis of negative T wave].

Electrotonic modulation, also known as electrical memory, is a phenomenon characterized by the presence of negative T waves following a period of abnormal ventricular activation. We present the case of an 86-year-old woman with dilated cardiomyopathy who was admitted for a laparoscopic left hemicolectomy. Despite an uneventful postoperative course, the patient developed electrocardiographic changes initially interpreted as ischemic. However, considering her medical history, the nature of the electrocardiographic alterations, and their subsequent evolution, electrotonic modulation emerged as the most probable differential diagnosis, ultimately confirmed as the definitive diagnosis.