2026 | Verified Practice Questions with Correct
Answers & Detailed Rationales | Complete Cardiac
Rhythm Interpretation Study Guide for RNs &
Healthcare Professionals
Question 1
A patient presents with a heart rate of 150 bpm and narrow QRS complexes. What is
the most likely diagnosis?
A) Atrial flutter
B) Ventricular tachycardia
C) Supraventricular tachycardia (SVT) (Correct Option)
D) Atrial fibrillation
Rationale: SVT is characterized by a rapid heart rate (often over 150 bpm) and narrow
QRS complexes due to its origin above the ventricles.
Question 2
During an emergency, a patient is found to have a ventricular rate of 180 bpm with
wide QRS complexes. What is the immediate nursing intervention?
A) Administer a beta-blocker
B) Prepare for synchronized cardioversion (Correct Option)
C) Administer oxygen
D) Monitor vital signs
Rationale: Wide QRS tachycardia at this rate is concerning for ventricular tachycardia,
which may require synchronized cardioversion as an immediate intervention to restore
normal rhythm.
Question 3
A patient exhibits a prolonged QT interval on the ECG. Which of the following
medications could potentially exacerbate this condition?
A) Aspirin
B) Sotalol (Correct Option)
C) Metoprolol
D) Atorvastatin
Rationale: Sotalol is known to prolong the QT interval and can lead to life-threatening
arrhythmias such as Torsades de Pointes.
Question 4
What is the most critical step for a nurse to take when a patient experiences
,syncope during an episode of atrial fibrillation?
A) Administer anticoagulants
B) Assess the patient's airway and consciousness (Correct Option)
C) Start an IV line
D) Measure blood pressure
Rationale: Assessing the patient's airway and consciousness is crucial in any syncope
event to ensure safety and determine the need for immediate resuscitation.
Question 5
A patient is diagnosed with third-degree heart block. What is the priority nursing
intervention?
A) Monitor the patient's blood pressure
B) Prepare for potential pacing (Correct Option)
C) Administer antiarrhythmic medication
D) Educate the patient about lifestyle changes
Rationale: Third-degree heart block can cause severe bradycardia and requires urgent
intervention, often with pacing to maintain adequate heart rate and prevent
complications.
Question 6
A 60-year-old patient with a history of heart failure presents with irregularly
irregular rhythms and an elevated heart rate. What should the nurse assess for?
A) Signs of pulmonary congestion (Correct Option)
B) Elevated blood glucose levels
C) Increased urine output
D) Elevated serum electrolytes
Rationale: In patients with heart failure and atrial fibrillation, there is an increased risk
of pulmonary congestion due to ineffective ventricular filling and elevated heart rates.
Question 7
What does a ‘sawtooth’ pattern in leads II, III, and aVF indicate?
A) Atrial fibrillation
B) Atrial flutter (Correct Option)
C) Ventricular tachycardia
D) Sinus tachycardia
Rationale: The ‘sawtooth’ pattern, or "F-waves," is characteristic of atrial flutter,
particularly in the inferior leads.
,Question 8
If a patient exhibits a junctional rhythm with a rate of 45 bpm, what is the
appropriate nursing action?
A) Start external pacing
B) Assess for signs of decreased cardiac output (Correct Option)
C) Administer atropine
D) Increase IV fluid rate
Rationale: Junctional rhythms can lead to decreased heart rates and may cause
decreased cardiac output, so assessing for signs of this is critical before any
interventions.
Question 9
After administering adenosine for SVT, the patient becomes briefly asystolic. What
is the best nursing response?
A) Prepare for intubation
B) Monitor the patient closely for a return of rhythm (Correct Option)
C) Administer CPR immediately
D) Assess for signs of myocardial infarction
Rationale: A brief period of asystole can occur after adenosine administration; close
monitoring is essential, as normal rhythm typically resumes shortly after.
Question 10
A patient presents with a new-onset wide complex tachycardia. What should the
nurse assess for?
A) Hypotension
B) Possible myocardial ischemia (Correct Option)
C) Elevated potassium levels
D) Fever
Rationale: Wide complex tachycardia can be indicative of ventricular tachycardia or
other serious dysrhythmias, often associated with myocardial ischemia or infarction.
Question 11
A patient in the ICU is on a continuous ECG monitor. The rhythm shows periodic
peaks resembling "tombstones." What does this indicate?
A) Atrial fibrillation
B) Myocardial ischemia (Correct Option)
C) Ventricular tachycardia
D) Sinus bradycardia
Rationale: The "tombstone" appearance on the ECG indicates ST elevation, which is a
sign of myocardial ischemia or infarction.
, Question 12
A patient presents with a heart rate of 40 bpm and is showing signs of confusion.
What is the priority nursing intervention?
A) Administer oxygen
B) Initiate a 12-lead ECG (Correct Option)
C) Start IV fluids
D) Monitor vital signs
Rationale: With bradycardia and altered mental status, obtaining a 12-lead ECG is
critical to determine the underlying cause and appropriate treatment.
Question 13
When monitoring a patient with atrial fibrillation, what is the most important
parameter to assess?
A) Blood glucose levels
B) Heart rate and rhythm (Correct Option)
C) Respiratory rate
D) Temperature
Rationale: Monitoring heart rate and rhythm is crucial in atrial fibrillation to prevent
complications like stroke and heart failure.
Question 14
A patient has a history of coronary artery disease and presents with ventricular
tachycardia. What is the most appropriate initial treatment?
A) Administer magnesium
B) Synchronized cardioversion (Correct Option)
C) Administer aspirin
D) Monitor for 24 hours
Rationale: Synchronized cardioversion is indicated for unstable ventricular
tachycardia, especially in patients with a history of coronary artery disease.
Question 15
In a patient with tachycardia and a wide QRS complex, which medication should
the nurse prepare to administer?
A) Adenosine
B) Amiodarone (Correct Option)
C) Digoxin
D) Diltiazem