RELIAS DYSRHYTHMIA BASIC
A EXAM
2025/2026
20 Questions with Correct Answers and Rationales
Already Graded A+ | 100% Verified
Subject: Dysrhythmia Interpretation Competency
Focus: Basic ECG Rhythm Recognition
Target: RNs, LPNs, and Telemetry Monitor Technicians
Format: Multiple Choice with Rationales
Date: 2025/2026
Ethical Reminder: Complete assessments using authorized training materials and AHA ACLS resources.
, Relias Dysrhythmia Basic A Exam | 2025/2026
Examination Questions
Instructions: Read each question carefully. Select the best answer. Correct answers are indicated in bold
cyan, followed by a clinical rationale explaining the reasoning.
1. [Cardiac Conduction System] Which structure is considered the primary pacemaker of the heart
and normally initiates each cardiac impulse?
A. Atrioventricular (AV) Node
B. Sinoatrial (SA) Node
C. Bundle of His
D. Purkinje Fibers
Rationale: The SA node, located in the upper wall of the right atrium, is the heart's natural pacemaker. It
generates electrical impulses at a rate of 60–100 bpm under normal conditions. The AV node (A) normally
delays conduction but does not initiate the impulse. The Bundle of His (C) and Purkinje fibers (D) are
conduction pathways with slower intrinsic rates (40–60 bpm and 20–40 bpm, respectively) and serve only
as backup pacemakers.
2. [ECG Paper & Measurement] On standard ECG paper, the width of one small box represents
which of the following?
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.12 seconds
Rationale: One small box on standard ECG paper equals 0.04 seconds (40 milliseconds) horizontally. One
large box (5 small boxes) equals 0.20 seconds. This fundamental measurement is essential for calculating
heart rate, assessing PR intervals, and measuring QRS duration. The PR interval of 0.12–0.20 sec (D) is
measured across 3–5 small boxes. Option B (0.10 sec) represents 2.5 small boxes.
3. [Heart Rate Calculation] A nurse is calculating heart rate using the 1500 method. If the R-to-
R interval measures 20 small boxes, what is the heart rate?
A. 60 bpm
B. 75 bpm
C. 85 bpm
2
A EXAM
2025/2026
20 Questions with Correct Answers and Rationales
Already Graded A+ | 100% Verified
Subject: Dysrhythmia Interpretation Competency
Focus: Basic ECG Rhythm Recognition
Target: RNs, LPNs, and Telemetry Monitor Technicians
Format: Multiple Choice with Rationales
Date: 2025/2026
Ethical Reminder: Complete assessments using authorized training materials and AHA ACLS resources.
, Relias Dysrhythmia Basic A Exam | 2025/2026
Examination Questions
Instructions: Read each question carefully. Select the best answer. Correct answers are indicated in bold
cyan, followed by a clinical rationale explaining the reasoning.
1. [Cardiac Conduction System] Which structure is considered the primary pacemaker of the heart
and normally initiates each cardiac impulse?
A. Atrioventricular (AV) Node
B. Sinoatrial (SA) Node
C. Bundle of His
D. Purkinje Fibers
Rationale: The SA node, located in the upper wall of the right atrium, is the heart's natural pacemaker. It
generates electrical impulses at a rate of 60–100 bpm under normal conditions. The AV node (A) normally
delays conduction but does not initiate the impulse. The Bundle of His (C) and Purkinje fibers (D) are
conduction pathways with slower intrinsic rates (40–60 bpm and 20–40 bpm, respectively) and serve only
as backup pacemakers.
2. [ECG Paper & Measurement] On standard ECG paper, the width of one small box represents
which of the following?
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.12 seconds
Rationale: One small box on standard ECG paper equals 0.04 seconds (40 milliseconds) horizontally. One
large box (5 small boxes) equals 0.20 seconds. This fundamental measurement is essential for calculating
heart rate, assessing PR intervals, and measuring QRS duration. The PR interval of 0.12–0.20 sec (D) is
measured across 3–5 small boxes. Option B (0.10 sec) represents 2.5 small boxes.
3. [Heart Rate Calculation] A nurse is calculating heart rate using the 1500 method. If the R-to-
R interval measures 20 small boxes, what is the heart rate?
A. 60 bpm
B. 75 bpm
C. 85 bpm
2
