What typically indicates unstable ischemia?

Unstable ischemia is characterized by sudden changes in chest pain or discomfort, which may occur at rest or with minimal exertion. This is particularly concerning because it suggests that the heart muscle is not receiving enough blood supply, indicating a worsening condition that requires immediate medical evaluation. The presence of chest pain under these circumstances is a classic symptom of unstable angina and can signal an increased risk for myocardial infarction.

In contrast, chest pain during vigorous exercise is more typical of stable ischemia, where symptoms occur predictably with exertion. Weakness and dizziness may accompany various conditions but do not specifically characterize unstable ischemia. Increased energy levels suggest good cardiovascular health and are not consistent with ischemic events. Therefore, chest pain at rest or with minimal effort stands out as the key indicator of unstable ischemia, making it the correct choice.