Certified EKG Technician (CET) Practice Exam 2025 – Comprehensive Test Prep

Monitoring changes in ST segments is crucial for identifying signs of myocardial ischemia during an EKG. Ischemia occurs when the blood supply to the heart muscle is reduced, leading to insufficient oxygenation. This condition often manifests as changes in the ST segment of the EKG trace.

Elevations or depressions in the ST segment can indicate damage or stress to the heart tissue. For instance, ST segment elevation may suggest an acute myocardial infarction, while ST segment depression can reflect subendocardial ischemia or coronary artery disease. Therefore, careful observation of these segment changes provides essential information about the heart's status and helps guide further diagnostic and therapeutic interventions.

While other symptoms such as increased heart rate, decreased blood pressure, or decreased respiratory rate can accompany ischemia, they are not specific markers observed directly on the EKG tracing. Instead, the ST segment changes provide a direct and specific indicator of ischemic conditions within the heart muscle, making it the most critical element to monitor during an EKG for signs of ischemia.