INTERPRETATION ASSESSMENT: EXAM
(LATEST UPDATE 2026/2027) | QUESTIONS
AND ANSWERS | GRADE A | 100% CORRECT
(VERIFIED SOLUTIONS)
Practice Questions 1–100 (WITH FULL RATIONALES)
Question 1
You have a 78-year-old patient who is hemodynamically unstable with an altered level of consciousness. The
rhythm strip shows regular P waves with a slow ventricular response.
What is the ventricular rate?
A. 40 bpm
B. 50 bpm
C. 60 bpm
Correct Answer: B. 50 bpm
Rationale:
Ventricular rate is calculated by counting large boxes between R waves and dividing into 300. A rhythm
with approximately six large boxes between QRS complexes corresponds to a rate of about 50 bpm.
Bradycardia at this rate can significantly reduce cardiac output in elderly patients. This explains the patient’s
hemodynamic instability and altered mental status.
Question 2
You have a 78-year-old patient who is hemodynamically unstable with altered level of consciousness. The
rhythm strip shows consistent P waves preceding each QRS.
What is the PR interval?
,A. 0.14 seconds
B. 0.16 seconds
C. 0.20 seconds
Correct Answer: B. 0.16 seconds
Rationale:
The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. Normal
PR interval ranges from 0.12 to 0.20 seconds. A PR of 0.16 seconds is within normal limits, indicating
normal AV nodal conduction. This helps rule out AV blocks in this rhythm.
Question 3
What is the QRS duration?
A. 0.08 seconds
B. 0.10 seconds
C. 0.12 seconds
Correct Answer: C. 0.12 seconds
Rationale:
The QRS complex represents ventricular depolarization. A duration of 0.12 seconds is at the upper limit of
normal and suggests possible intraventricular conduction delay. Wider QRS complexes reduce the efficiency
of ventricular contraction. This contributes to decreased cardiac output in unstable patients.
Question 4
What is the QT interval?
A. 0.36–0.40 seconds
B. 0.40–0.44 seconds
C. 0.44–0.46 seconds
Correct Answer: B. 0.40–0.44 seconds
Rationale:
The QT interval reflects total ventricular depolarization and repolarization. Normal QT varies with heart rate
but generally should be less than half the R-R interval. A QT of 0.40–0.44 seconds is borderline prolonged
and may predispose to ventricular dysrhythmias. QT prolongation is clinically significant in unstable
patients.
,Question 5
Identify this rhythm.
A. Sinus bradycardia
B. Wandering atrial pacemaker
C. Both A & B are correct
Correct Answer: C. Both A & B are correct
Rationale:
Sinus bradycardia is identified by a heart rate below 60 bpm with normal P wave morphology. Wandering
atrial pacemaker is characterized by varying P wave shapes due to multiple atrial pacemaker sites. When
both slow rate and variable P waves are present, both diagnoses apply. This rhythm can reduce cardiac
output in elderly patients.
QUESTIONS (6–100)
(All exam-level, KP-style, with deep rationales)
Question 6
Which rhythm originates from the SA node at a rate of 60–100 bpm?
A. Atrial flutter
B. Normal sinus rhythm
C. Junctional rhythm
Correct Answer: B. Normal sinus rhythm
Rationale:
Normal sinus rhythm originates from the sinoatrial node and maintains a regular rhythm with consistent P
waves. The rate must fall between 60 and 100 bpm. Proper SA node function ensures coordinated atrial and
ventricular contraction. This rhythm provides optimal cardiac output.
Question 7
Which finding confirms atrial fibrillation?
A. Regular R-R intervals
B. Sawtooth flutter waves
C. Absence of distinct P waves
, Correct Answer: C. Absence of distinct P waves
Rationale:
Atrial fibrillation is characterized by chaotic atrial activity resulting in the absence of identifiable P waves.
The ventricular rhythm is irregularly irregular. This rhythm significantly increases the risk of
thromboembolism. Rate control and anticoagulation are often required.
Question 8
A QRS duration greater than 0.12 seconds suggests:
A. Normal ventricular conduction
B. Ventricular origin or conduction delay
C. Atrial depolarization
Correct Answer: B. Ventricular origin or conduction delay
Rationale:
Wide QRS complexes indicate delayed ventricular depolarization. This may result from bundle branch block
or ventricular rhythms. Wide complexes decrease cardiac efficiency. Prompt recognition is critical in
unstable patients.
Question 9
Which rhythm is most commonly associated with digoxin toxicity?
A. Sinus tachycardia
B. Ventricular fibrillation
C. Atrial tachycardia with block
Correct Answer: C. Atrial tachycardia with block
Rationale:
Digoxin increases vagal tone and can cause enhanced atrial automaticity with AV block. This unique
combination strongly suggests digoxin toxicity. Early recognition prevents progression to life-threatening
arrhythmias. Serum drug levels should be evaluated.
Question 10
Which rhythm requires immediate defibrillation?