Q 1: Can Q wave be normal?

Q 2: When is Q wave significant? 

Q 3: Identify the leads showing Q wave in this EKG. Are they normal or abnormal?

Answer

Answers

Q 1: Can Q wave be normal?

Usually very small or absent

A Q wave in III and AVR is normal.

Q 2: When is Q wave significant? 

Abnormal:

• A Q wave is significant if it is greater than 1 box wide (0.04 secs) in leads other than III and AVR
• Greater than 1/3 the amplitude of the QRS complex.
• Greater than 1/4th of R wave

Abnormal Q waves: indicate presence of infarct

Q 3: Identify the leads showing Q wave in this EKG. Are they normal or abnormal?

II, III and aVF. Normal Q waves.