RELIAS BASIC DYSRHYTHMIA TEST
2026/2027 | Complete Study Guide | Practice
Questions, Verified Answers & ECG Rhythm
Interpretation
RELIAS BASIC DYSRHYTHMIA TEST 2026/2027 | Complete Study Guide
• Comprehensive 200-question practice exam designed to build mastery of
cardiac dysrhythmias through systematic review and detailed evidence-based
rationales covering interpretation, mechanisms, and clinical management.
• Study guide format enables active learning—answer each question, review
the rationale to reinforce concepts, and develop confident ECG rhythm
interpretation skills essential for RELIAS certification.
SECTION 1: BASIC CONCEPTS & NORMAL SINUS RHYTHM
1. What is the normal cardiac rate for an adult in normal sinus rhythm (NSR)?
A) 40-60 beats per minute
B) 60-100 beats per minute
C) 100-120 beats per minute
D) 120-150 beats per minute
E) 150-200 beats per minute
B) 60-100 beats per minute
Rationale: Normal sinus rhythm in adults ranges from 60-100 beats per minute.
This represents the baseline rhythm originating from the SA node with normal AV
conduction. Rates below 60 are considered bradycardia, while rates above 100 are
tachycardia. This is the fundamental benchmark for rhythm interpretation.
,2. In normal sinus rhythm, which component of the ECG represents atrial
repolarization?
A) The P wave
B) The PR interval
C) The QRS complex
D) The T wave
E) The U wave
E) The U wave
Rationale: The U wave, when visible, represents atrial repolarization. However, the
P wave represents atrial depolarization. The QRS complex represents ventricular
depolarization, and the T wave represents ventricular repolarization. The U wave is
often not visible on normal ECGs but when present appears after the T wave and
before the next P wave.
3. What is the normal duration of the PR interval in an adult?
A) 0.04-0.08 seconds
B) 0.08-0.12 seconds
C) 0.12-0.20 seconds
D) 0.20-0.28 seconds
E) 0.28-0.40 seconds
C) 0.12-0.20 seconds
Rationale: The PR interval represents the time from the start of atrial
depolarization (P wave) to the start of ventricular depolarization (QRS complex).
This interval reflects conduction through the atria, AV node, and bundle of His. A
normal PR interval of 0.12-0.20 seconds (3-5 small squares on ECG paper) indicates
,appropriate AV conduction. Prolongation beyond 0.20 seconds indicates first-
degree AV block.
4. Which wave on the ECG represents ventricular depolarization?
A) P wave
B) QRS complex
C) T wave
D) U wave
E) PR segment
B) QRS complex
Rationale: The QRS complex represents the rapid depolarization of the ventricles.
It is composed of three components: Q wave (initial negative deflection), R wave
(first positive deflection), and S wave (negative deflection after R wave). The QRS
complex typically lasts 0.06-0.10 seconds (less than 2.5 small squares) and is the
most prominent deflection on the ECG.
5. What is the normal duration of the QRS complex?
A) Less than 0.06 seconds
B) 0.06-0.10 seconds
C) 0.10-0.14 seconds
D) 0.14-0.20 seconds
E) Greater than 0.20 seconds
B) 0.06-0.10 seconds
, Rationale: A normal QRS complex duration is 0.06-0.10 seconds (1.5-2.5 small
squares on ECG paper). This represents normal ventricular depolarization through
the bundle branches. QRS complexes wider than 0.10 seconds suggest bundle
branch block, ventricular ectopy, or abnormal conduction pathways and warrant
further investigation.
SECTION 2: SINUS RHYTHMS
6. What characterizes sinus tachycardia?
A) Heart rate 40-60 bpm with normal P waves
B) Heart rate greater than 100 bpm with normal P waves before each QRS
C) Irregular rhythm with absent P waves
D) Heart rate 60-100 bpm with widened QRS
E) Heart rate below 40 bpm with normal conduction
B) Heart rate greater than 100 bpm with normal P waves before each QRS
Rationale: Sinus tachycardia is a sinus rhythm with a rate exceeding 100 beats per
minute. All characteristics of normal sinus rhythm remain intact: regular rhythm,
normal P waves present before each QRS complex, normal PR interval, and normal
QRS duration. Common causes include fever, anxiety, pain, hypoxia, heart failure,
and sympathomimetic medications. It is a response to physiological demand rather
than a primary arrhythmia.
7. What is the most common cause of sinus tachycardia in hospitalized
patients?
A) Digitalis toxicity
B) Fever or infection
2026/2027 | Complete Study Guide | Practice
Questions, Verified Answers & ECG Rhythm
Interpretation
RELIAS BASIC DYSRHYTHMIA TEST 2026/2027 | Complete Study Guide
• Comprehensive 200-question practice exam designed to build mastery of
cardiac dysrhythmias through systematic review and detailed evidence-based
rationales covering interpretation, mechanisms, and clinical management.
• Study guide format enables active learning—answer each question, review
the rationale to reinforce concepts, and develop confident ECG rhythm
interpretation skills essential for RELIAS certification.
SECTION 1: BASIC CONCEPTS & NORMAL SINUS RHYTHM
1. What is the normal cardiac rate for an adult in normal sinus rhythm (NSR)?
A) 40-60 beats per minute
B) 60-100 beats per minute
C) 100-120 beats per minute
D) 120-150 beats per minute
E) 150-200 beats per minute
B) 60-100 beats per minute
Rationale: Normal sinus rhythm in adults ranges from 60-100 beats per minute.
This represents the baseline rhythm originating from the SA node with normal AV
conduction. Rates below 60 are considered bradycardia, while rates above 100 are
tachycardia. This is the fundamental benchmark for rhythm interpretation.
,2. In normal sinus rhythm, which component of the ECG represents atrial
repolarization?
A) The P wave
B) The PR interval
C) The QRS complex
D) The T wave
E) The U wave
E) The U wave
Rationale: The U wave, when visible, represents atrial repolarization. However, the
P wave represents atrial depolarization. The QRS complex represents ventricular
depolarization, and the T wave represents ventricular repolarization. The U wave is
often not visible on normal ECGs but when present appears after the T wave and
before the next P wave.
3. What is the normal duration of the PR interval in an adult?
A) 0.04-0.08 seconds
B) 0.08-0.12 seconds
C) 0.12-0.20 seconds
D) 0.20-0.28 seconds
E) 0.28-0.40 seconds
C) 0.12-0.20 seconds
Rationale: The PR interval represents the time from the start of atrial
depolarization (P wave) to the start of ventricular depolarization (QRS complex).
This interval reflects conduction through the atria, AV node, and bundle of His. A
normal PR interval of 0.12-0.20 seconds (3-5 small squares on ECG paper) indicates
,appropriate AV conduction. Prolongation beyond 0.20 seconds indicates first-
degree AV block.
4. Which wave on the ECG represents ventricular depolarization?
A) P wave
B) QRS complex
C) T wave
D) U wave
E) PR segment
B) QRS complex
Rationale: The QRS complex represents the rapid depolarization of the ventricles.
It is composed of three components: Q wave (initial negative deflection), R wave
(first positive deflection), and S wave (negative deflection after R wave). The QRS
complex typically lasts 0.06-0.10 seconds (less than 2.5 small squares) and is the
most prominent deflection on the ECG.
5. What is the normal duration of the QRS complex?
A) Less than 0.06 seconds
B) 0.06-0.10 seconds
C) 0.10-0.14 seconds
D) 0.14-0.20 seconds
E) Greater than 0.20 seconds
B) 0.06-0.10 seconds
, Rationale: A normal QRS complex duration is 0.06-0.10 seconds (1.5-2.5 small
squares on ECG paper). This represents normal ventricular depolarization through
the bundle branches. QRS complexes wider than 0.10 seconds suggest bundle
branch block, ventricular ectopy, or abnormal conduction pathways and warrant
further investigation.
SECTION 2: SINUS RHYTHMS
6. What characterizes sinus tachycardia?
A) Heart rate 40-60 bpm with normal P waves
B) Heart rate greater than 100 bpm with normal P waves before each QRS
C) Irregular rhythm with absent P waves
D) Heart rate 60-100 bpm with widened QRS
E) Heart rate below 40 bpm with normal conduction
B) Heart rate greater than 100 bpm with normal P waves before each QRS
Rationale: Sinus tachycardia is a sinus rhythm with a rate exceeding 100 beats per
minute. All characteristics of normal sinus rhythm remain intact: regular rhythm,
normal P waves present before each QRS complex, normal PR interval, and normal
QRS duration. Common causes include fever, anxiety, pain, hypoxia, heart failure,
and sympathomimetic medications. It is a response to physiological demand rather
than a primary arrhythmia.
7. What is the most common cause of sinus tachycardia in hospitalized
patients?
A) Digitalis toxicity
B) Fever or infection
