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

Normal sinus rhythm in adults is defined as a heart rate of 60–100 bpm with a regular rhythm and consistent P-wave morphology.

Question 2

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

Accepted Answer

Chaotic, irregular waveforms with no identifiable QRS complexes

Answer

Ventricular fibrillation produces disorganized, chaotic electrical activity with no identifiable P waves, QRS complexes, or T waves.

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

The PR interval spans from the start of the P wave to the beginning of the QRS complex, reflecting conduction from the SA node through the AV node to the bundle of His.

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

SVT typically presents with a regular rate of 150–250 bpm, narrow QRS complexes, and P waves buried within or immediately following the QRS.

Question 5

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

Accepted Answer

0.06–0.10 seconds

Answer

A normal QRS duration of 0.06–0.10 seconds reflects rapid ventricular depolarization via the intact His-Purkinje system.

(ECC) Emergency Cardiovascular Care Certification Practice Test

(ECC) Emergency Cardiovascular Care Certification Practice Test

ECC Cardiac Rhythm Recognition & Interpretation