CRAT ECG Waveform Measurements and Intervals

Question 1

What is the normal duration of the PR interval on a standard ECG?

Accepted Answer

0.12–0.20 seconds

Answer

The normal PR interval ranges from 0.12 to 0.20 seconds (3–5 small squares).

Question 2

On standard ECG paper, one large square represents how many seconds?

Accepted Answer

0.20 seconds

Answer

One large square on standard ECG paper equals 0.20 seconds (200 ms) at the standard paper speed of 25 mm/sec.

Question 3

A QRS complex measuring 0.14 seconds is considered:

Accepted Answer

Wide or abnormal

Answer

A QRS duration greater than 0.12 seconds is considered wide and suggests a bundle branch block or ventricular origin.

Question 4

The QT interval is measured from:

Accepted Answer

Start of Q wave to end of T wave

Answer

The QT interval is measured from the beginning of the QRS complex to the end of the T wave and represents total ventricular depolarization and repolarization.

Question 5

Which waveform on the ECG represents ventricular repolarization?

Accepted Answer

T wave

Answer

The T wave represents ventricular repolarization — the recovery phase of the ventricles after contraction.

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT - Certified Rhythm Analysis Technician Practice Test

CRAT ECG Waveform Measurements and Intervals