Dysrhythmia Basic B Exam
Cardiac Rhythm Interpretation
Official Practice Exam -- 2026/2027 Edition
35 Questions 90 Minutes 80% Passing Score Recertification
TABLE OF CONTENTS
Section 1: Cardiac Anatomy & Electrophysiology 8 Questions
Section 2: Sinus & Atrial Rhythms 9 Questions
Section 3: Junctional & Ventricular Rhythms 9 Questions
Section 4: Heart Blocks & Pacemaker Rhythms 9 Questions
INSTRUCTIONS
This practice exam contains 35 multiple-choice questions divided into four sections. You have 90 minutes to
complete the entire exam. Each question has four answer choices (A, B, C, D). Select the single best answer
for each question. A passing score of 80% (28 correct out of 35) is required. Read each scenario carefully
before selecting your answer. The correct answer and rationale are provided immediately after each question
for study purposes. This exam is designed to mirror the content and difficulty of the actual RELIAS Dysrhythmia
Basic B certification assessment. Review the rationales thoroughly to strengthen your understanding of cardiac
rhythm interpretation principles.
Disclaimer: This is an independent practice resource and is not affiliated with, endorsed by, or connected to Relias Learning
or its parent organizations.
RELIAS Dysrhythmia Basic B -- 2026/2027 | Passing Score: 80% | Page 1 of 21
, Cardiac Anatomy & Electrophysiology -- 2026/2027
Q1 Question 1 of 35
A 54-year-old male is admitted to the telemetry unit after presenting with chest
discomfort and palpitations. The nurse recalls that the primary pacemaker of the heart
under normal conditions initiates electrical impulses at a rate of 60 to 100 beats per
minute. Which structure of the heart is responsible for this function?
Sinoatrial (SA) node
Atrioventricular (AV) node
Bundle of His
Purkinje fiber network
Correct Answer: A
Rationale:
The SA node is the heart's natural pacemaker, located at the junction of the superior vena cava and
the right atrium, and it normally fires at 60 to 100 bpm. The AV node serves as a secondary
pacemaker at 40 to 60 bpm, while the Bundle of His and Purkinje fibers fire at even slower rates of 20
to 40 bpm.
Q2 Question 2 of 35
A 67-year-old female is being monitored in the cardiac care unit following a myocardial
infarction. The healthcare provider explains that the electrical conduction system
normally delays impulses briefly at a specific structure to allow the atria to fully contract
before the ventricles depolarize. Where does this critical delay occur?
Sinoatrial (SA) node
Atrioventricular (AV) node
Bundle branches
Purkinje fiber network
Correct Answer: B
Rationale:
The AV node provides a critical delay of approximately 0.12 to 0.20 seconds, allowing the atria to
finish contracting and emptying blood into the ventricles before ventricular depolarization begins. The
SA node initiates the impulse, and the bundle branches and Purkinje fibers conduct rapidly without
intentional delay.
RELIAS Dysrhythmia Basic B -- 2026/2027 | Passing Score: 80% | Page 2 of 21
, Cardiac Anatomy & Electrophysiology -- 2026/2027
Q3 Question 3 of 35
A 42-year-old male undergoes an electrophysiology study that reveals a prolonged PR
interval on his ECG. The cardiologist explains that this finding indicates a delay in
conduction through a specific portion of the electrical pathway. Which segment of the
conduction system is most likely affected?
Left bundle branch
Right bundle branch
Atrioventricular (AV) node and His-Purkinje system
Sinoatrial (SA) node
Correct Answer: C
Rationale:
The PR interval measures the time from the onset of atrial depolarization to the onset of ventricular
depolarization, and it primarily reflects conduction through the AV node and the His-Purkinje system.
A prolonged PR interval indicates delayed conduction in this region, commonly called a first-degree
AV block. Bundle branch blocks affect the QRS duration, not the PR interval.
Q4 Question 4 of 35
A nursing student is reviewing cardiac electrophysiology and asks why ventricular
fibrillation is immediately life-threatening. The preceptor explains that during ventricular
fibrillation, the ventricles lose their coordinated contraction pattern. What is the primary
consequence of this disorganized electrical activity?
Increased cardiac output with tachycardia
Slow but sustained ventricular contraction
Rapid atrial depolarization with irregular conduction
Complete cessation of effective cardiac output
Correct Answer: D
Rationale:
Ventricular fibrillation produces chaotic, disorganized electrical activity that prevents the ventricles
from contracting in a coordinated manner, resulting in no effective cardiac output and rapid
hemodynamic collapse. Without immediate defibrillation, ventricular fibrillation leads to death within
minutes.
RELIAS Dysrhythmia Basic B -- 2026/2027 | Passing Score: 80% | Page 3 of 21