Relias Dysrhythmia Basic Test A Answers
(35 Q&A) 2026/2027
Q1: An ECG strip shows a regular rhythm, a heart rate of 42 bpm, a normal PR
interval of 0.16 seconds, and a narrow QRS complex of 0.08 seconds. What is
this rhythm?
Answer: Sinus Bradycardia
Rationale: The rhythm is regular and originating from the SA node (normal
P waves and PR interval), but the rate is less than 60 bpm, meeting the
criteria for sinus bradycardia.
Q2: While calculating a heart rate on an irregular ECG strip, how many large
boxes or seconds should the strip ideally span to use the standard estimation
method?
Answer: 6 seconds (30 large boxes)
, Rationale: For irregular rhythms like Atrial Fibrillation, the most accurate
method is counting the number of R waves in a 6-second strip and
multiplying by 10.
Q3: A patient's telemetry monitor displays a sudden run of wide, bizarre QRS
complexes occurring at a rate of 160 bpm with no discernible P waves. The run
lasts for 5 beats before returning to sinus rhythm. How is this documented?
Answer: A short run of Non-Sustained Ventricular Tachycardia (NSVT)
Rationale: Ventricular tachycardia is defined as three or more consecutive
ventricular beats (wide QRS > 0.12s) at a rate greater than 100 bpm.
Because it terminated on its own within 30 seconds, it is non-sustained.
Q4: Which of the following best describes the PR interval characteristics found
in a First-Degree AV Block?
Answer: The PR interval is prolonged (> 0.20 seconds) but remains constant
across every single beat.
Rationale: In a first-degree heart block, conduction through the AV node is
delayed rather than blocked. This results in a lengthened PR interval that
does not change from beat to beat, and every P wave is followed by a QRS.
, Q5: A patient's ECG strip exhibits a chaotic, wavy baseline with no identifiable P
waves and a highly irregular R-R interval. What is the priority diagnosis for this
rhythm?
Answer: Atrial Fibrillation (A-Fib)
Rationale: Atrial fibrillation is characterized by the total absence of distinct
P waves (replaced by chaotic fibrillatory waves) and an irregularly irregular
ventricular response.
Q6: What is the normal physiological duration of a standard QRS complex in an
adult patient?
Answer: 0.06 to 0.11 seconds (less than 3 small boxes)
Rationale: A normal QRS complex indicates rapid ventricular depolarization
via the bundle branches and Purkinje network. A width of 0.12 seconds or
greater indicates a conduction delay (such as a bundle branch block) or a
ventricular origin.
Q7: On an ECG strip, you notice that the PR intervals become progressively
longer with each consecutive beat until a P wave appears without an associated
QRS complex. Following the dropped beat, the cycle repeats. What rhythm is
this?
(35 Q&A) 2026/2027
Q1: An ECG strip shows a regular rhythm, a heart rate of 42 bpm, a normal PR
interval of 0.16 seconds, and a narrow QRS complex of 0.08 seconds. What is
this rhythm?
Answer: Sinus Bradycardia
Rationale: The rhythm is regular and originating from the SA node (normal
P waves and PR interval), but the rate is less than 60 bpm, meeting the
criteria for sinus bradycardia.
Q2: While calculating a heart rate on an irregular ECG strip, how many large
boxes or seconds should the strip ideally span to use the standard estimation
method?
Answer: 6 seconds (30 large boxes)
, Rationale: For irregular rhythms like Atrial Fibrillation, the most accurate
method is counting the number of R waves in a 6-second strip and
multiplying by 10.
Q3: A patient's telemetry monitor displays a sudden run of wide, bizarre QRS
complexes occurring at a rate of 160 bpm with no discernible P waves. The run
lasts for 5 beats before returning to sinus rhythm. How is this documented?
Answer: A short run of Non-Sustained Ventricular Tachycardia (NSVT)
Rationale: Ventricular tachycardia is defined as three or more consecutive
ventricular beats (wide QRS > 0.12s) at a rate greater than 100 bpm.
Because it terminated on its own within 30 seconds, it is non-sustained.
Q4: Which of the following best describes the PR interval characteristics found
in a First-Degree AV Block?
Answer: The PR interval is prolonged (> 0.20 seconds) but remains constant
across every single beat.
Rationale: In a first-degree heart block, conduction through the AV node is
delayed rather than blocked. This results in a lengthened PR interval that
does not change from beat to beat, and every P wave is followed by a QRS.
, Q5: A patient's ECG strip exhibits a chaotic, wavy baseline with no identifiable P
waves and a highly irregular R-R interval. What is the priority diagnosis for this
rhythm?
Answer: Atrial Fibrillation (A-Fib)
Rationale: Atrial fibrillation is characterized by the total absence of distinct
P waves (replaced by chaotic fibrillatory waves) and an irregularly irregular
ventricular response.
Q6: What is the normal physiological duration of a standard QRS complex in an
adult patient?
Answer: 0.06 to 0.11 seconds (less than 3 small boxes)
Rationale: A normal QRS complex indicates rapid ventricular depolarization
via the bundle branches and Purkinje network. A width of 0.12 seconds or
greater indicates a conduction delay (such as a bundle branch block) or a
ventricular origin.
Q7: On an ECG strip, you notice that the PR intervals become progressively
longer with each consecutive beat until a P wave appears without an associated
QRS complex. Following the dropped beat, the cycle repeats. What rhythm is
this?
