Certified EkG technician (CET) Practice Exam

In an EKG, what does a prolonged QT interval indicate?

1. Risk for ventricular tachycardia

2. Normal cardiac function

3. Bradycardia

4. Atrial enlargement

The correct answer is: Risk for ventricular tachycardia

A prolonged QT interval is an important finding on an EKG that signifies potential cardiac risk, particularly for ventricular tachycardia and other serious arrhythmias. The QT interval represents the time it takes for the heart's ventricles to depolarize and then repolarize after each heartbeat. When this interval is prolonged, it suggests that the heart's electrical system is taking longer than normal to recharge each beat, which can lead to dangerous situations such as torsades de pointes, a specific form of ventricular tachycardia. While a normal cardiac function would typically correlate with a standard QT interval, and bradycardia might cause various heart rhythm issues, it is not specifically indicated by a prolonged QT interval. Moreover, atrial enlargement does not directly relate to the QT interval. Understanding the implications of a prolonged QT interval is crucial for identifying patients who are at increased risk for life-threatening arrhythmias, making risk for ventricular tachycardia the correct interpretation.