T Wave

Question 1

What does the T wave represent in an ECG?

Answer 1

Ventricular repolarization

The T wave follows the QRS complex

Question 2

What are the characteristics of a normal T wave?

Answer 2

Asymmetric, less than half the height of the QRS complex, oriented in the same direction as the QRS complex

If the QRS complex is predominantly upright, so should the T wave

Question 3

What does the first half of the T wave represent?

Answer 3

Absolute refractory period (ARP)

This is the portion closest to the QRS complex

Question 4

What does the second half of the T wave represent?

Answer 4

Relative refractory period (RRP)

This is the portion farthest from the QRS complex

Question 5

What changes occur to the T wave during myocardial ischemia?

Answer 5

Becomes very large (hyperacute), peaked or tented, symmetric, and broad

These changes indicate significant cardiac events

Question 6

What type of T wave is seen with hyperkalemia?

Answer 6

Tall, pointed (peaked) T waves

Hyperkalemia is an elevated potassium level in the blood

Question 7

What does a deeply inverted T wave indicate?

Answer 7

Acute CNS events such as intracranial hemorrhage or massive stroke

This is a critical finding in ECG interpretation

Question 8

What is a U wave and when is it seen?

Answer 8

A wave seen after the T wave and before the next P wave

It is thought to represent the final stage of ventricular repolarization

Question 9

What is the usual direction of the U wave in relation to the T wave?

Answer 9

Same as that of the preceding T wave in lead II

This consistency in direction is important for ECG analysis

Question 10

What is considered an abnormal U wave height?

Answer 10

U wave taller than 2 mm

This may indicate hypokalemia or cardiomyopathy among other conditions