Certified Cardiographic Technician (CCT) Practice Exam 2026 – Your All-in-One Guide to Exam Success!

In the context of interpreting an electrocardiogram (ECG), transmural myocardial infarction is characterized by specific changes that occur in the ECG tracing. ST segment elevation, significant Q waves, and T wave inversion are all indicative of transmural infarction because they reflect the damage and ischemia of the myocardial tissue.

ST segment elevation occurs during an acute myocardial infarction, indicating that there is a region of myocardial injury. This segment usually elevates due to the increased intracavity pressures and altered repolarization processes as a result of the infarction.

Significant Q waves signify that there has been necrosis of the heart muscle. In a healthy heart, waves may not present in this way; the presence of significant Q waves typically means there has been a loss of viable myocardial tissue following an infarction.

T wave inversion can happen after the initial injury phase and is part of the evolving changes seen in myocardial infarction.

On the other hand, ST segment depression is not indicative of a transmural myocardial infarction but rather suggests subendocardial ischemia. Thus, it often points to angina or non-transmural ischemia rather than a full-thickness infarction through the myocardium. This distinction is crucial when interpreting ECGs and