Basic Arrhythmia Comprehensive Exam Prep | Rhythm
Recognition, ECG Interpretation & Practice Questions
2026/2027
QUESTION 1
What are the defining electrocardiographic criteria for a normal sinus
rhythm (NSR)?
A. Regular rhythm, rate between 60 and 100 beats per minute, upright
P wave in lead II preceding every QRS complex, PR interval of 0.12 to
0.20 seconds, and QRS duration less than 0.12 seconds
B. Irregular rhythm, rate exceeding 100 beats per minute, absent P
waves, and wide QRS complexes
C. Regular rhythm, rate between 40 and 60 beats per minute, inverted P
waves, and prolonged PR intervals
D. Absent QRS complexes with a flatline tracing
Correct Answer: A. Regular rhythm, rate between 60 and 100 beats per
minute, upright P wave in lead II preceding every QRS complex, PR
interval of 0.12 to 0.20 seconds, and QRS duration less than 0.12
seconds
Detailed Rationale: Normal sinus rhythm originates in the sinus node
with normal conduction pathways, meeting standard parameters for
rate, regularity, and waveform intervals.
QUESTION 2
What heart rate range characterizes Sinus Bradycardia?
,A. Less than 60 beats per minute
B. Between 60 and 100 beats per minute
C. Between 100 and 150 beats per minute
D. Greater than 150 beats per minute
Correct Answer: A. Less than 60 beats per minute
Detailed Rationale: Sinus bradycardia retains normal sinus morphology
(upright P waves, normal intervals) but features an intrinsic rate slower
than 60 beats per minute.
QUESTION 3
What heart rate range characterizes Sinus Tachycardia?
A. Greater than 100 beats per minute
B. Between 60 and 100 beats per minute
C. Less than 60 beats per minute
D. Exactly 60 beats per minute
Correct Answer: A. Greater than 100 beats per minute
Detailed Rationale: Sinus tachycardia is identified when the sinus node
fires at a rate exceeding 100 beats per minute, with normal underlying
P-wave and QRS morphology.
QUESTION 4
What is the standard normal duration of the PR interval on an ECG?
A. 0.12 to 0.20 seconds (3 to 5 small boxes)
B. 0.04 to 0.10 seconds (1 to 2.5 small boxes)
,C. 0.22 to 0.30 seconds
D. Exactly 0.50 seconds
Correct Answer: A. 0.12 to 0.20 seconds (3 to 5 small boxes)
Detailed Rationale: The PR interval reflects the time taken for electrical
impulses to travel from the SA node through the AV node and
ventricles; normal duration spans 0.12 to 0.20 seconds.
QUESTION 5
What is the normal duration limit for a narrow QRS complex in an
adult?
A. Less than 0.12 seconds (fewer than 3 small boxes)
B. Exactly 0.20 seconds
C. 0.25 to 0.40 seconds
D. Greater than 0.50 seconds
Correct Answer: A. Less than 0.12 seconds (fewer than 3 small boxes)
Detailed Rationale: A normal QRS complex representing rapid
ventricular depolarization should measure less than 0.12 seconds;
wider complexes indicate intraventricular conduction delays.
QUESTION 6
What are the hallmark ECG features of Atrial Fibrillation?
A. Irregularly irregular ventricular rhythm, absence of discrete P waves,
and a chaotic, undulating baseline composed of fibrillatory waves
B. Regular rhythm with a sawtooth pattern in leads II, III, and aVF
C. A slow regular rate of 40 beats per minute with hidden P waves
, D. Wide, bizarre complexes recurring at exact intervals
Correct Answer: A. Irregularly irregular ventricular rhythm, absence of
discrete P waves, and a chaotic, undulating baseline composed of
fibrillatory waves
Detailed Rationale: Atrial fibrillation is characterized by uncoordinated
atrial activation, producing no true P waves and resulting in a
completely irregular ventricular response.
QUESTION 7
What is the characteristic ECG appearance of Atrial Flutter?
A. Regular or variable ventricular rhythm with distinct "sawtooth" or
"picket-fence" flutter waves (F-waves) replacing normal P waves
B. Totally random chaotic baseline with no identifiable waves
C. Single isolated premature beats with a normal baseline
D. Inverted P waves following every wide QRS complex
Correct Answer: A. Regular or variable ventricular rhythm with distinct
"sawtooth" or "picket-fence" flutter waves (F-waves) replacing normal P
waves
Detailed Rationale: Atrial flutter involves a macro-reentrant circuit in
the right atrium, generating characteristic flutter waves best visualized
in inferior leads II, III, and aVF.
QUESTION 8
How is a First-Degree Atrioventricular (AV) Block defined on an ECG?
A. Prolonged PR interval exceeding 0.20 seconds, with every P wave
consistently followed by a QRS complex
Recognition, ECG Interpretation & Practice Questions
2026/2027
QUESTION 1
What are the defining electrocardiographic criteria for a normal sinus
rhythm (NSR)?
A. Regular rhythm, rate between 60 and 100 beats per minute, upright
P wave in lead II preceding every QRS complex, PR interval of 0.12 to
0.20 seconds, and QRS duration less than 0.12 seconds
B. Irregular rhythm, rate exceeding 100 beats per minute, absent P
waves, and wide QRS complexes
C. Regular rhythm, rate between 40 and 60 beats per minute, inverted P
waves, and prolonged PR intervals
D. Absent QRS complexes with a flatline tracing
Correct Answer: A. Regular rhythm, rate between 60 and 100 beats per
minute, upright P wave in lead II preceding every QRS complex, PR
interval of 0.12 to 0.20 seconds, and QRS duration less than 0.12
seconds
Detailed Rationale: Normal sinus rhythm originates in the sinus node
with normal conduction pathways, meeting standard parameters for
rate, regularity, and waveform intervals.
QUESTION 2
What heart rate range characterizes Sinus Bradycardia?
,A. Less than 60 beats per minute
B. Between 60 and 100 beats per minute
C. Between 100 and 150 beats per minute
D. Greater than 150 beats per minute
Correct Answer: A. Less than 60 beats per minute
Detailed Rationale: Sinus bradycardia retains normal sinus morphology
(upright P waves, normal intervals) but features an intrinsic rate slower
than 60 beats per minute.
QUESTION 3
What heart rate range characterizes Sinus Tachycardia?
A. Greater than 100 beats per minute
B. Between 60 and 100 beats per minute
C. Less than 60 beats per minute
D. Exactly 60 beats per minute
Correct Answer: A. Greater than 100 beats per minute
Detailed Rationale: Sinus tachycardia is identified when the sinus node
fires at a rate exceeding 100 beats per minute, with normal underlying
P-wave and QRS morphology.
QUESTION 4
What is the standard normal duration of the PR interval on an ECG?
A. 0.12 to 0.20 seconds (3 to 5 small boxes)
B. 0.04 to 0.10 seconds (1 to 2.5 small boxes)
,C. 0.22 to 0.30 seconds
D. Exactly 0.50 seconds
Correct Answer: A. 0.12 to 0.20 seconds (3 to 5 small boxes)
Detailed Rationale: The PR interval reflects the time taken for electrical
impulses to travel from the SA node through the AV node and
ventricles; normal duration spans 0.12 to 0.20 seconds.
QUESTION 5
What is the normal duration limit for a narrow QRS complex in an
adult?
A. Less than 0.12 seconds (fewer than 3 small boxes)
B. Exactly 0.20 seconds
C. 0.25 to 0.40 seconds
D. Greater than 0.50 seconds
Correct Answer: A. Less than 0.12 seconds (fewer than 3 small boxes)
Detailed Rationale: A normal QRS complex representing rapid
ventricular depolarization should measure less than 0.12 seconds;
wider complexes indicate intraventricular conduction delays.
QUESTION 6
What are the hallmark ECG features of Atrial Fibrillation?
A. Irregularly irregular ventricular rhythm, absence of discrete P waves,
and a chaotic, undulating baseline composed of fibrillatory waves
B. Regular rhythm with a sawtooth pattern in leads II, III, and aVF
C. A slow regular rate of 40 beats per minute with hidden P waves
, D. Wide, bizarre complexes recurring at exact intervals
Correct Answer: A. Irregularly irregular ventricular rhythm, absence of
discrete P waves, and a chaotic, undulating baseline composed of
fibrillatory waves
Detailed Rationale: Atrial fibrillation is characterized by uncoordinated
atrial activation, producing no true P waves and resulting in a
completely irregular ventricular response.
QUESTION 7
What is the characteristic ECG appearance of Atrial Flutter?
A. Regular or variable ventricular rhythm with distinct "sawtooth" or
"picket-fence" flutter waves (F-waves) replacing normal P waves
B. Totally random chaotic baseline with no identifiable waves
C. Single isolated premature beats with a normal baseline
D. Inverted P waves following every wide QRS complex
Correct Answer: A. Regular or variable ventricular rhythm with distinct
"sawtooth" or "picket-fence" flutter waves (F-waves) replacing normal P
waves
Detailed Rationale: Atrial flutter involves a macro-reentrant circuit in
the right atrium, generating characteristic flutter waves best visualized
in inferior leads II, III, and aVF.
QUESTION 8
How is a First-Degree Atrioventricular (AV) Block defined on an ECG?
A. Prolonged PR interval exceeding 0.20 seconds, with every P wave
consistently followed by a QRS complex
