A depressed ST segment on an ECG is indicative of which condition?

A depressed ST segment on an ECG is indicative of which condition?

• A. Myocardial infarction
• B. Subendocardial ischemia
• C. Hyperkalemia
• D. Atrial flutter

Answer: (B)

A depressed ST segment on an ECG is primarily indicative of subendocardial ischemia. This condition occurs when the heart muscle, specifically the inner layer (subendocardium), experiences a reduced blood supply, often due to conditions like unstable angina or other instances of myocardial ischemia. During periods of ischemia, the electrical activity of the heart is altered, which leads to the characteristic ST segment depression on the ECG. ST segment depression can present in a variety of scenarios, indicating that the heart is not receiving sufficient blood flow, particularly during exercise or stress. In clinical practice, this finding is commonly associated with coronary artery disease and can help direct further investigation or intervention. While myocardial infarction is associated with ST segment changes, it typically presents with ST segment elevation or significant changes rather than mere depression. Hyperkalemia generally causes peaked T waves and eventual widening of the QRS complex rather than ST segment depression. Atrial flutter, on the other hand, primarily manifests with a distinct pattern of flutter waves and does not typically lead to changes in the ST segment. Thus, in the context of an ECG interpretation, recognizing that a depressed ST segment signifies subendocardial ischemia is crucial for diagnosing and managing patients with potential coronary artery disease or

A depressed ST segment on an ECG is primarily indicative of subendocardial ischemia. This condition occurs when the heart muscle, specifically the inner layer (subendocardium), experiences a reduced blood supply, often due to conditions like unstable angina or other instances of myocardial ischemia. During periods of ischemia, the electrical activity of the heart is altered, which leads to the characteristic ST segment depression on the ECG.

ST segment depression can present in a variety of scenarios, indicating that the heart is not receiving sufficient blood flow, particularly during exercise or stress. In clinical practice, this finding is commonly associated with coronary artery disease and can help direct further investigation or intervention.

While myocardial infarction is associated with ST segment changes, it typically presents with ST segment elevation or significant changes rather than mere depression. Hyperkalemia generally causes peaked T waves and eventual widening of the QRS complex rather than ST segment depression. Atrial flutter, on the other hand, primarily manifests with a distinct pattern of flutter waves and does not typically lead to changes in the ST segment.

Thus, in the context of an ECG interpretation, recognizing that a depressed ST segment signifies subendocardial ischemia is crucial for diagnosing and managing patients with potential coronary artery disease or