Understanding EKG and Cardiac Cycle

What is the standard paper speed for an EKG machine?

• 10 mm/s

• 25 mm/s

• 50 mm/s

• 100 mm/s

How many small boxes on an EKG strip represent 1 second?

• 5

• 10

• 20

• 25

What is the duration of one small box on an EKG strip?

• 0.02 seconds

• 0.04 seconds

• 0.1 seconds

• 0.2 seconds

Which wave on the EKG represents atrial depolarization?

• P wave

• Q wave

• R wave

• T wave

Calculate the heart rate if the R-R interval is 20 small boxes on an EKG strip.

• 75 bpm

• 100 bpm

• 150 bpm

• 300 bpm

What is the normal range for the PR interval on an EKG?

• 0.04 to 0.08 seconds

• 0.08 to 0.12 seconds

• 0.12 to 0.20 seconds

• 0.20 to 0.24 seconds

If the QRS complex is 3 small boxes wide, what is its duration?

• 0.06 seconds

• 0.08 seconds

• 0.12 seconds

• 0.16 seconds

Which part of the cardiac cycle does the T wave represent?

• Atrial depolarization

• Ventricular depolarization

• Ventricular repolarization

• Atrial repolarization

What is the significance of the ST segment on an EKG?

• Atrial depolarization

• Ventricular depolarization

• Ventricular repolarization

• Time between ventricular depolarization and repolarization

How many leads are used in a standard EKG?

• 3

• 6

• 12

• 15