ECC Cardiac Rhythm Recognition & Interpretation

Question 1

What is the normal heart rate range for an adult in normal sinus rhythm?

Accepted Answer

60–100 bpm

Answer

40–60 bpm

Answer

100–120 bpm

Answer

120–160 bpm

Question 2

Which ECG finding is characteristic of ventricular fibrillation (VF)?

Accepted Answer

Chaotic, irregular waveforms with no identifiable QRS complexes

Answer

Regular narrow QRS complexes at 150 bpm

Answer

Wide QRS complexes at a rate of 150–250 bpm

Answer

Sawtooth flutter waves at 300 bpm

Question 3

What does the PR interval on a 12-lead ECG represent?

Accepted Answer

Time from onset of atrial depolarization to start of ventricular depolarization

Answer

Time for ventricular depolarization

Answer

Time for atrial repolarization only

Answer

Duration of the complete cardiac cycle

Question 4

A regular narrow-complex tachycardia at 180 bpm with no visible P waves is most consistent with which rhythm?

Accepted Answer

Supraventricular tachycardia (SVT)

Answer

Atrial fibrillation

Answer

Ventricular tachycardia

Answer

Sinus tachycardia

Question 5

What is the normal duration of a QRS complex on ECG?

Accepted Answer

0.06–0.10 seconds

Answer

Less than 0.04 seconds

Answer

0.12–0.20 seconds

Answer

0.20–0.30 seconds

Question 6

In atrial fibrillation, how is the ventricular response best characterized?

Accepted Answer

Irregularly irregular rhythm

Answer

Regular rhythm with rate of 60–100 bpm

Answer

Regular rhythm with rate greater than 150 bpm

Answer

Regularly irregular rhythm with grouped beats

Question 7

Which ECG finding defines first-degree AV block?

Accepted Answer

PR interval greater than 0.20 seconds with all P waves conducted

Answer

Progressive PR lengthening until a P wave is not conducted

Answer

Fixed 2:1 ratio of P waves to QRS complexes

Answer

Complete dissociation between P waves and QRS complexes