What ECG finding indicates high-risk non-ST-segment elevation acute coronary syndromes (NSTE-ACS)?

The presence of T-wave inversion in two or more contiguous leads is a significant ECG finding associated with high-risk non-ST-segment elevation acute coronary syndromes (NSTE-ACS). This finding reflects myocardial ischemia, which can be indicative of underlying severe coronary artery disease. When the T waves are inverted, it shows that there is a disturbance in the heart's electrical recovery phase, which often occurs in areas of the myocardium that are not receiving adequate blood supply due to narrowed or blocked arteries.

Contiguous leads refer to those that are anatomically and electrically connected, representing the same region of the heart. The inversion in these leads suggests that the ischemia is more widespread, thus increasing the risk of further cardiac events, such as a myocardial infarction. This is why it is essential for healthcare providers to closely monitor patients who present with this finding, as they may require immediate intervention.

The other options, while they may indicate different cardiac issues, do not have the same direct correlation to high-risk NSTE-ACS as T-wave inversion does. For instance, Q waves in all leads typically signify a previous myocardial infarction rather than ongoing ischemia. A prolonged QT interval can increase the risk of certain types of arrhythmias but is not directly linked