CPR - Certified Paramedic Response ECG Rhythm Interpretation Questions and Answers 1 — Questions and Answers
Question 1: A paramedic is analyzing an ECG strip of a 68-year-old male complaining of dizziness. The strip shows a ventricular rate of 40 bpm, a regular rhythm, P waves that are not associated with any QRS complexes, and narrow QRS complexes. Which rhythm is most likely represented on this ECG?
- Second-Degree AV Block, Type I
- Atrial Fibrillation with a slow ventricular response
- Third-Degree (Complete) AV Block (Correct answer)
- Sinus Bradycardia
Correct answer: Third-Degree (Complete) AV Block
Third-Degree AV Block is characterized by a complete dissociation between atrial and ventricular activity. The P waves (atrial depolarizations) occur at their own regular rate, while the QRS complexes (ventricular depolarizations) occur at a separate, slower, regular escape rate. There is no consistent PR interval because the atria and ventricles are not communicating electrically.
Question 2: You are dispatched to a 72-year-old female patient complaining of palpitations and shortness of breath. The cardiac monitor displays a narrow-complex tachycardia at a rate of 170 bpm with a regular rhythm. P waves are not clearly identifiable. Which of the following is the most likely interpretation of this rhythm?
- Atrial Fibrillation
- Sinus Tachycardia
- Ventricular Tachycardia
- Supraventricular Tachycardia (SVT) (Correct answer)
Correct answer: Supraventricular Tachycardia (SVT)
Supraventricular Tachycardia (SVT) is a rapid heart rhythm originating above the ventricles. It is characterized by a regular, narrow QRS complex tachycardia, typically with a rate between 150-250 bpm. P waves are often difficult to see as they can be buried in the preceding T wave.
Question 3: Which of the following ECG findings is the most definitive characteristic of Atrial Fibrillation?
- A 'sawtooth' pattern of P waves
- An irregularly irregular rhythm (Correct answer)
- A progressively lengthening PR interval
- Wide, bizarre-looking QRS complexes
Correct answer: An irregularly irregular rhythm
The hallmark of Atrial Fibrillation is an 'irregularly irregular' rhythm. This is caused by chaotic, uncoordinated electrical impulses from the atria bombarding the AV node, which then allows impulses to pass through to the ventricles at irregular intervals. There are no discernible P waves, only fibrillatory waves.
Question 4: A paramedic identifies a regular rhythm with a rate of 140 bpm, narrow QRS complexes, and a 'sawtooth' pattern of flutter waves instead of P waves. This rhythm is best identified as:
- Atrial Flutter (Correct answer)
- Ventricular Fibrillation
- Junctional Tachycardia
- Sinus Tachycardia
Correct answer: Atrial Flutter
Atrial Flutter is characterized by a rapid, regular atrial depolarization from a re-entry circuit, which creates a classic 'sawtooth' pattern of flutter waves on the ECG. The ventricular response can be regular or variable depending on how many flutter waves are conducted through the AV node.
Question 5: While assessing a patient, you note a wide-complex tachycardia on the monitor with a rate of 180 bpm and a regular rhythm. The patient is pulseless and apneic. What is the most appropriate immediate action?
- Administer Amiodarone
- Perform synchronized cardioversion
- Begin high-quality CPR and prepare for defibrillation (Correct answer)
- Obtain a 12-lead ECG
Correct answer: Begin high-quality CPR and prepare for defibrillation
This patient is in cardiac arrest. The rhythm described is pulseless Ventricular Tachycardia (pVT). According to ACLS guidelines, the immediate priority for a shockable rhythm like pVT is to start high-quality CPR and deliver a defibrillation shock as soon as possible.
Question 6: What does the PR interval on an ECG tracing represent, and what is its normal duration?
- Ventricular depolarization; 0.12-0.20 seconds
- The time for the electrical impulse to travel from the SA node to the ventricles; 0.12-0.20 seconds (Correct answer)
- Ventricular repolarization; 0.06-0.10 seconds
- The time for the electrical impulse to travel from the SA node to the ventricles; 0.06-0.10 seconds
Correct answer: The time for the electrical impulse to travel from the SA node to the ventricles; 0.12-0.20 seconds
The PR interval measures the time from the beginning of the P wave (atrial depolarization) to the beginning of the QRS complex (ventricular depolarization). It represents the time it takes for the electrical impulse to travel from the sinoatrial (SA) node through the atria and the atrioventricular (AV) node. The normal duration is 0.12 to 0.20 seconds.
CPR - Certified Paramedic Response ECG Rhythm Interpretation Questions and Answers 1
A paramedic is analyzing an ECG strip of a 68-year-old male complaining of dizziness.
The strip shows a ventricular rate of 40 bpm, a regular rhythm, P waves that are not associated with any QRS complexes, and narrow QRS complexes.
Which rhythm is most likely represented on this ECG?