Which of the following best describes the appearance of T waves in a normal heart?

• A. Flat
• B. Inverted
• C. Upright
• D. Variable

Answer: (C)

T waves on an ECG represent the repolarization of the ventricles, and in a normal heart, they typically appear upright in most leads. This upright appearance is a reflection of the direction of the electrical activity during ventricular repolarization, which usually follows the pattern of depolarization. In leads such as I, II, and V5-V6, an upright T wave indicates a normal electrical recovery phase of the heart.

The T wave can have variations in shape or height due to changes in heart rate, electrolyte imbalances, or other physiological conditions, but in a healthy individual, the consistent characteristic is the upright orientation. Understanding the normal appearance of T waves is essential for interpreting ECGs accurately and recognizing deviations that may indicate underlying cardiac issues.