CCI - Cardiovascular Credentialing International ECG Rhythm Interpretation Questions and Answers

Question 1

A patient's cardiac monitor displays a rhythm with a ventricular rate varying between 110 and 150 bpm.
The R-R intervals are irregularly irregular, and no discernible P waves can be identified.
Which of the following is the most likely interpretation?

Accepted Answer

Atrial Fibrillation

Answer

Sinus Tachycardia

Answer

Atrial Flutter with variable block

Answer

Multifocal Atrial Tachycardia

Question 2

Which of the following ECG findings is the defining characteristic of a third-degree atrioventricular (AV) block?

Accepted Answer

Complete dissociation of P waves and QRS complexes, with atria and ventricles beating independently.

Answer

A progressively lengthening PR interval followed by a dropped QRS complex.

Answer

A constant and prolonged PR interval (>0.20 seconds) for every QRS.

Answer

A regular rhythm with a rate of 40-60 bpm and inverted P waves.

Question 3

A monitor alarm sounds, revealing a regular, wide-complex rhythm at a rate of 170 bpm. The patient becomes dizzy and hypotensive. This presentation is most consistent with which life-threatening arrhythmia?

Accepted Answer

Ventricular Tachycardia

Answer

Supraventricular Tachycardia with aberrancy

Answer

Atrial Fibrillation with a rapid ventricular response

Answer

Sinus Tachycardia

Question 4

An ECG rhythm strip shows a ventricular rate of approximately 75 bpm. The baseline has a distinctive, repetitive "sawtooth" appearance, with four atrial waves for every one QRS complex. What is the most likely rhythm?

Accepted Answer

Atrial Flutter

Answer

Atrial Fibrillation

Answer

Sinus Bradycardia with U waves

Answer

Junctional Rhythm

Question 5

When analyzing an ECG, the PR interval reflects the time for the electrical impulse to travel from the SA node through the AV node. What is the normal duration for this interval?

Accepted Answer

0.12 - 0.20 seconds

Answer

0.06 - 0.11 seconds

Answer

> 0.20 seconds

Answer

< 0.12 seconds

Question 6

While observing a cardiac monitor, you note an occasional complex that occurs earlier than expected, is wide and bizarre in shape, and is not preceded by a P wave. This ectopic beat is followed by a full compensatory pause. What is this beat called?

Accepted Answer

Premature Ventricular Contraction (PVC)

Answer

Premature Atrial Contraction (PAC)

Answer

Premature Junctional Contraction (PJC)

Answer

Aberrantly Conducted PAC

A patient's cardiac monitor displays a rhythm with a ventricular rate varying between 110 and 150 bpm.The R-R intervals are irregularly irregular, and no discernible P waves can be identified.Which of the following is the most likely interpretation?

A patient's cardiac monitor displays a rhythm with a ventricular rate varying between 110 and 150 bpm.
The R-R intervals are irregularly irregular, and no discernible P waves can be identified.
Which of the following is the most likely interpretation?