Advanced Patient Assessment Practice Exam

What problem is indicated by elevation of the ST segment?

1. Myocardial ischemia

2. Depletion of serum potassium

3. Heart block

4. Elevation of serum potassium

The correct answer is: Myocardial ischemia

Elevation of the ST segment on an electrocardiogram (ECG) is a critical sign that typically indicates myocardial ischemia, specifically acute myocardial infarction (AMI) or a heart attack. This change occurs when the heart muscle is not receiving adequate blood flow and, consequently, oxygen. The elevation reflects a significant electrical disturbance caused by injury to the myocardial cells. In the context of a heart attack, the ST segment elevation signals that there is a blockage in a coronary artery, leading to injury to the heart muscle. It is important for healthcare professionals to recognize this adaptation on the ECG promptly, as it guides timely interventions, such as reperfusion therapy, to restore blood flow and limit myocardial damage. The other options pertain to different cardiac or metabolic conditions. Depletion of serum potassium could cause changes in the ECG, but it does not specifically result in ST segment elevation. Similarly, heart block typically manifests as a prolonged PR interval or dropped beats rather than ST segment changes. Elevation of serum potassium may lead to different ECG alterations, such as peaked T waves rather than ST segment elevation. Understanding these distinctions is essential for accurate interpretation of the ECG and for providing appropriate patient care.