Expansive negative T waves were observed in a patient with chronic respiratory failure. The electrocardiogram (ECG) revealed expansive negative T waves in leads I, II, aVL, and V_<3-6>, and the ECG changes persisted for three months. Cardiac enzymes did not rise throughout the course, although these ECG findings suggested acute myocardial ischemia. Seven days after the onset of the ECG changes, a transient ischemic attack occurred in the vertebrobasilar territory. Although a relationship between these ECG changes and cerebral ischemia is unknown, such ECG changes in the absence of myocardial damage might be caused by ischemia of the vertebrobasilar territory, especially the hypothalamus, and might occur as a premonitory sign of transient ischemic attacks.