HCA EKG INTERPRETATION EXAM (2025/2026
UPDATE) |GUARANTEED ACCURATE ANSWERS
|LATEST VERSION, Exams of Nursing
Section 1: Rate, Rhythm, & Basic Intervals (Questions 1-20)
1. A 65-year-old male presents with palpitations and dizziness. His EKG shows a regular
rhythm with a heart rate of 150 bpm. There are no visible P waves, but there are
"sawtooth" waves in leads II, III, and aVF. What is the most likely rhythm?
A) Sinus Tachycardia
B) Atrial Fibrillation
C) Atrial Flutter
D) AV Nodal Reentrant Tachycardia (AVNRT)
Answer: C) Atrial Flutter
Rationale: Atrial flutter is characterized by a regular atrial rate of 250-350 bpm, often with a
2:1, 3:1, or 4:1 AV conduction block, resulting in a ventricular rate that is a fraction of the atrial
rate. The classic "sawtooth" or "flutter" waves (F-waves) are best seen in the inferior leads (II,
III, aVF). This is distinct from Atrial Fibrillation (irregularly irregular, no P waves) and Sinus
Tachycardia (P waves present).
2. A 72-year-old patient with a history of hypertension presents with a complaint of
intermittent "skipped heartbeats." His EKG shows an irregularly irregular rhythm with a
heart rate of 80 bpm. No distinct P waves are visible. The baseline is chaotic. What is the
most appropriate initial management for this stable patient?
A) Immediate synchronized cardioversion
B) Rate control with a beta-blocker or calcium channel blocker
C) Aspirin and Clopidogrel
D) Immediate IV Amiodarone
, Answer: B) Rate control with a beta-blocker or calcium channel blocker
Rationale: The EKG shows Atrial Fibrillation (AFib) with a controlled rate. AFib is
characterized by an irregularly irregular rhythm and the absence of P waves. Since the patient is
stable (not in rapid ventricular response with shock), the initial management is rate control
(goal <110 bpm) using beta-blockers (metoprolol) or non-dihydropyridine calcium channel
blockers (diltiazem). Anticoagulation is based on the CHA₂DS₂-VASc score.
3. A 28-year-old female with no past medical history presents with sudden onset of
palpitations and a sense of "fluttering" in her chest. Her EKG shows a narrow-complex
tachycardia with a heart rate of 180 bpm. The rhythm is regular, and there are no
discernible P waves. What is the most likely diagnosis?
A) Ventricular Tachycardia
B) Sinus Tachycardia
C) Atrial Fibrillation
D) AV Nodal Reentrant Tachycardia (AVNRT)
Answer: D) AV Nodal Reentrant Tachycardia (AVNRT)
Rationale: AVNRT is the most common cause of paroxysmal supraventricular tachycardia (SVT)
in young, healthy patients. It presents with sudden onset, regular, narrow-complex tachycardia
(usually 140-250 bpm), and the absence of P waves (because they are hidden in the QRS
complex). Vagal maneuvers or Adenosine is the treatment of choice for acute termination.
4. A 55-year-old patient on digoxin presents with bradycardia and nausea. His EKG shows
a ventricular rate of 42 bpm. The P waves are normal, but the PR interval is prolonged to
0.36 seconds. What is this rhythm called?
A) First-degree AV block
B) Second-degree AV block, Type I (Wenckebach)
C) Second-degree AV block, Type II (Mobitz II)
D) Third-degree AV block
Answer: A) First-degree AV block
Rationale: First-degree AV block is defined as a PR interval >0.20 seconds (200 ms). In this
case, it is markedly prolonged at 0.36 seconds. It is a conduction delay at the AV node. It is often
asymptomatic and can be caused by medications (digoxin, beta-blockers, calcium channel
blockers). It does not cause dropped beats; every P wave is followed by a QRS.
, 5. A 68-year-old patient presents with syncope. His EKG shows a regular rhythm with a
heart rate of 38 bpm. The P waves are present and are not associated with the QRS
complexes (AV dissociation). The QRS complex is wide (>0.12 seconds). What is the
diagnosis?
A) Complete Heart Block (Third-degree AV block) with a ventricular escape rhythm
B) Second-degree AV block Type I
C) Second-degree AV block Type II
D) Atrial fibrillation with slow ventricular response
Answer: A) Complete Heart Block (Third-degree AV block) with a ventricular escape
rhythm
Rationale: Third-degree AV block (complete heart block) is the complete dissociation of atrial
and ventricular activity. P waves have no relationship to QRS complexes. The ventricular rate is
typically slow (30-40 bpm) and originates from a junctional (narrow QRS) or ventricular (wide
QRS) escape rhythm. This requires immediate temporary pacing and cardiology consultation.
6. A 32-year-old athlete presents for a pre-participation physical. His resting EKG shows a
heart rate of 54 bpm. The rhythm is regular. The PR interval is 0.24 seconds. The QRS is
normal. What is the most appropriate next step?
A) Refer for stress testing
B) Pacemaker insertion
C) Reassurance, no further evaluation is needed
D) Holter monitor for 24 hours
Answer: C) Reassurance, no further evaluation is needed
Rationale: First-degree AV block is common in young, healthy individuals, especially athletes,
due to increased vagal tone. It is a benign finding and does not require further workup or
treatment in the absence of symptoms. The PR interval is prolonged (>0.20s), but every P wave
conducts.
7. A 70-year-old patient on a cardiac monitor shows an irregular rhythm with intermittent
pauses. The EKG shows a pattern where the PR interval progressively lengthens until a
QRS is dropped. What is the name of this rhythm?
A) Wenckebach (Mobitz I)
B) Mobitz II
C) Complete heart block
D) Sinus arrhythmia
, Answer: A) Wenckebach (Mobitz I)
Rationale: Second-degree AV block Type I (Wenckebach) is characterized by a progressive
prolongation of the PR interval until a P wave is blocked (no QRS). This is a more benign form
of heart block usually at the AV node level and often requires no treatment unless symptomatic.
8. A 60-year-old patient presents with dizziness. His EKG shows an irregularly irregular
rhythm with no P waves. The ventricular rate is 148 bpm. What is the most immediate
concern for this patient?
A) Heart failure
B) Myocardial infarction
C) Thromboembolic stroke risk
D) Hemodynamic instability
Answer: D) Hemodynamic instability
Rationale: This is Atrial Fibrillation with Rapid Ventricular Response (RVR). The immediate
concern is the rapid heart rate compromising cardiac output and causing hemodynamic instability
(hypotension, chest pain, syncope). If unstable, immediate synchronized cardioversion is needed.
If stable, rate control is initiated. While stroke risk is a concern, it is a long-term risk, not
immediate.
9. A 50-year-old patient's EKG shows a heart rate of 120 bpm. The rhythm is regular. The
P waves are positive in lead II and negative in aVR. What is the rhythm?
A) Atrial tachycardia
B) Junctional tachycardia
C) Sinus tachycardia
D) Ventricular tachycardia
Answer: C) Sinus tachycardia
Rationale: Sinus tachycardia is characterized by a regular rhythm with a rate >100 bpm. The P
waves are upright (positive) in lead II and inverted (negative) in lead aVR, indicating that the
impulse originates from the sinoatrial (SA) node. The QRS is narrow. The rate is <150 bpm
typically (unless under extreme stress).
UPDATE) |GUARANTEED ACCURATE ANSWERS
|LATEST VERSION, Exams of Nursing
Section 1: Rate, Rhythm, & Basic Intervals (Questions 1-20)
1. A 65-year-old male presents with palpitations and dizziness. His EKG shows a regular
rhythm with a heart rate of 150 bpm. There are no visible P waves, but there are
"sawtooth" waves in leads II, III, and aVF. What is the most likely rhythm?
A) Sinus Tachycardia
B) Atrial Fibrillation
C) Atrial Flutter
D) AV Nodal Reentrant Tachycardia (AVNRT)
Answer: C) Atrial Flutter
Rationale: Atrial flutter is characterized by a regular atrial rate of 250-350 bpm, often with a
2:1, 3:1, or 4:1 AV conduction block, resulting in a ventricular rate that is a fraction of the atrial
rate. The classic "sawtooth" or "flutter" waves (F-waves) are best seen in the inferior leads (II,
III, aVF). This is distinct from Atrial Fibrillation (irregularly irregular, no P waves) and Sinus
Tachycardia (P waves present).
2. A 72-year-old patient with a history of hypertension presents with a complaint of
intermittent "skipped heartbeats." His EKG shows an irregularly irregular rhythm with a
heart rate of 80 bpm. No distinct P waves are visible. The baseline is chaotic. What is the
most appropriate initial management for this stable patient?
A) Immediate synchronized cardioversion
B) Rate control with a beta-blocker or calcium channel blocker
C) Aspirin and Clopidogrel
D) Immediate IV Amiodarone
, Answer: B) Rate control with a beta-blocker or calcium channel blocker
Rationale: The EKG shows Atrial Fibrillation (AFib) with a controlled rate. AFib is
characterized by an irregularly irregular rhythm and the absence of P waves. Since the patient is
stable (not in rapid ventricular response with shock), the initial management is rate control
(goal <110 bpm) using beta-blockers (metoprolol) or non-dihydropyridine calcium channel
blockers (diltiazem). Anticoagulation is based on the CHA₂DS₂-VASc score.
3. A 28-year-old female with no past medical history presents with sudden onset of
palpitations and a sense of "fluttering" in her chest. Her EKG shows a narrow-complex
tachycardia with a heart rate of 180 bpm. The rhythm is regular, and there are no
discernible P waves. What is the most likely diagnosis?
A) Ventricular Tachycardia
B) Sinus Tachycardia
C) Atrial Fibrillation
D) AV Nodal Reentrant Tachycardia (AVNRT)
Answer: D) AV Nodal Reentrant Tachycardia (AVNRT)
Rationale: AVNRT is the most common cause of paroxysmal supraventricular tachycardia (SVT)
in young, healthy patients. It presents with sudden onset, regular, narrow-complex tachycardia
(usually 140-250 bpm), and the absence of P waves (because they are hidden in the QRS
complex). Vagal maneuvers or Adenosine is the treatment of choice for acute termination.
4. A 55-year-old patient on digoxin presents with bradycardia and nausea. His EKG shows
a ventricular rate of 42 bpm. The P waves are normal, but the PR interval is prolonged to
0.36 seconds. What is this rhythm called?
A) First-degree AV block
B) Second-degree AV block, Type I (Wenckebach)
C) Second-degree AV block, Type II (Mobitz II)
D) Third-degree AV block
Answer: A) First-degree AV block
Rationale: First-degree AV block is defined as a PR interval >0.20 seconds (200 ms). In this
case, it is markedly prolonged at 0.36 seconds. It is a conduction delay at the AV node. It is often
asymptomatic and can be caused by medications (digoxin, beta-blockers, calcium channel
blockers). It does not cause dropped beats; every P wave is followed by a QRS.
, 5. A 68-year-old patient presents with syncope. His EKG shows a regular rhythm with a
heart rate of 38 bpm. The P waves are present and are not associated with the QRS
complexes (AV dissociation). The QRS complex is wide (>0.12 seconds). What is the
diagnosis?
A) Complete Heart Block (Third-degree AV block) with a ventricular escape rhythm
B) Second-degree AV block Type I
C) Second-degree AV block Type II
D) Atrial fibrillation with slow ventricular response
Answer: A) Complete Heart Block (Third-degree AV block) with a ventricular escape
rhythm
Rationale: Third-degree AV block (complete heart block) is the complete dissociation of atrial
and ventricular activity. P waves have no relationship to QRS complexes. The ventricular rate is
typically slow (30-40 bpm) and originates from a junctional (narrow QRS) or ventricular (wide
QRS) escape rhythm. This requires immediate temporary pacing and cardiology consultation.
6. A 32-year-old athlete presents for a pre-participation physical. His resting EKG shows a
heart rate of 54 bpm. The rhythm is regular. The PR interval is 0.24 seconds. The QRS is
normal. What is the most appropriate next step?
A) Refer for stress testing
B) Pacemaker insertion
C) Reassurance, no further evaluation is needed
D) Holter monitor for 24 hours
Answer: C) Reassurance, no further evaluation is needed
Rationale: First-degree AV block is common in young, healthy individuals, especially athletes,
due to increased vagal tone. It is a benign finding and does not require further workup or
treatment in the absence of symptoms. The PR interval is prolonged (>0.20s), but every P wave
conducts.
7. A 70-year-old patient on a cardiac monitor shows an irregular rhythm with intermittent
pauses. The EKG shows a pattern where the PR interval progressively lengthens until a
QRS is dropped. What is the name of this rhythm?
A) Wenckebach (Mobitz I)
B) Mobitz II
C) Complete heart block
D) Sinus arrhythmia
, Answer: A) Wenckebach (Mobitz I)
Rationale: Second-degree AV block Type I (Wenckebach) is characterized by a progressive
prolongation of the PR interval until a P wave is blocked (no QRS). This is a more benign form
of heart block usually at the AV node level and often requires no treatment unless symptomatic.
8. A 60-year-old patient presents with dizziness. His EKG shows an irregularly irregular
rhythm with no P waves. The ventricular rate is 148 bpm. What is the most immediate
concern for this patient?
A) Heart failure
B) Myocardial infarction
C) Thromboembolic stroke risk
D) Hemodynamic instability
Answer: D) Hemodynamic instability
Rationale: This is Atrial Fibrillation with Rapid Ventricular Response (RVR). The immediate
concern is the rapid heart rate compromising cardiac output and causing hemodynamic instability
(hypotension, chest pain, syncope). If unstable, immediate synchronized cardioversion is needed.
If stable, rate control is initiated. While stroke risk is a concern, it is a long-term risk, not
immediate.
9. A 50-year-old patient's EKG shows a heart rate of 120 bpm. The rhythm is regular. The
P waves are positive in lead II and negative in aVR. What is the rhythm?
A) Atrial tachycardia
B) Junctional tachycardia
C) Sinus tachycardia
D) Ventricular tachycardia
Answer: C) Sinus tachycardia
Rationale: Sinus tachycardia is characterized by a regular rhythm with a rate >100 bpm. The P
waves are upright (positive) in lead II and inverted (negative) in lead aVR, indicating that the
impulse originates from the sinoatrial (SA) node. The QRS is narrow. The rate is <150 bpm
typically (unless under extreme stress).
