Paramedic Cardiology 2026 Study Guide:
Practice Questions with Answer Explanations
ECG Interpretation • Arrhythmias • Acute
Coronary Syndrome • Cardiac Emergencies •
Exam Preparation
Domain 1: ECG Interpretation & Electrophysiology (Questions 1–25)
Question 1. What is the normal duration of the PR interval on a standard ECG?
A) 0.04–0.10 seconds
B) 0.12–0.20 seconds
C) 0.20–0.28 seconds
D) 0.28–0.36 seconds
Rationale: The PR interval represents atrial depolarization and conduction through
the AV node. Normal duration is 0.12–0.20 seconds (3–5 small boxes).
Prolongation beyond 0.20 seconds suggests first-degree AV block.
Question 2. What is the normal duration of the QRS complex?
A) 0.04–0.08 seconds
B) 0.08–0.12 seconds
C) 0.12–0.16 seconds
D) Greater than 0.16 seconds
Rationale: A normal QRS is less than 0.12 seconds (3 small boxes). Widening
beyond 0.12 seconds suggests bundle branch block, ventricular origin, or drug
toxicity.
Question 3. A rhythm strip shows 4 large boxes between R waves. What is the
approximate heart rate?
,A) 60 bpm
B) 75 bpm
C) 100 bpm
D) 150 bpm
Rationale: Using the 300 method, divide 300 by the number of large boxes
between R waves: 300 ÷ 4 = 75 bpm.
Question 4. A 6-second strip contains 12 QRS complexes. What is the heart rate?
A) 60 bpm
B) 72 bpm
C) 100 bpm
D) 120 bpm
Rationale: The 6-second method multiplies the number of QRS complexes by 10:
12 × 10 = 120 bpm.
Question 5. Where is the V1 electrode placed?
A) 4th intercostal space, left sternal border
B) 4th intercostal space, right sternal border
C) 5th intercostal space, midclavicular line
D) 5th intercostal space, midaxillary line
Rationale: V1 is placed in the 4th intercostal space at the right sternal border. V2
is at the left sternal border, V4 at the midclavicular line, and V6 at the midaxillary
line.
Question 6. Which leads view the inferior wall of the heart?
A) V1–V2
B) I, aVL, V5, V6
C) II, III, aVF
D) V3–V4
Rationale: Leads II, III, and aVF are inferior leads. ST elevation in two or more of
these leads indicates an inferior wall MI.
, Question 7. Which leads are considered lateral leads?
A) V1–V2
B) I, aVL, V5, V6
C) II, III, aVF
D) V3–V4
Rationale: Lateral leads are I, aVL, V5, and V6. They view the lateral wall of the
left ventricle.
Question 8. Which leads are considered anterior leads?
A) V1–V2
B) I, aVL
C) II, III, aVF
D) V3–V4
Rationale: V3 and V4 are anterior leads. Anterior MI is associated with LAD
occlusion and carries a high mortality risk.
Question 9. Which leads are considered septal leads?
A) V5–V6
B) V1–V2
C) I, aVL
D) II, III, aVF
Rationale: V1 and V2 view the interventricular septum. Septal involvement often
accompanies anterior MI.
Question 10. Which lead is most commonly used for continuous cardiac
monitoring?
A) V1
B) Lead II
Practice Questions with Answer Explanations
ECG Interpretation • Arrhythmias • Acute
Coronary Syndrome • Cardiac Emergencies •
Exam Preparation
Domain 1: ECG Interpretation & Electrophysiology (Questions 1–25)
Question 1. What is the normal duration of the PR interval on a standard ECG?
A) 0.04–0.10 seconds
B) 0.12–0.20 seconds
C) 0.20–0.28 seconds
D) 0.28–0.36 seconds
Rationale: The PR interval represents atrial depolarization and conduction through
the AV node. Normal duration is 0.12–0.20 seconds (3–5 small boxes).
Prolongation beyond 0.20 seconds suggests first-degree AV block.
Question 2. What is the normal duration of the QRS complex?
A) 0.04–0.08 seconds
B) 0.08–0.12 seconds
C) 0.12–0.16 seconds
D) Greater than 0.16 seconds
Rationale: A normal QRS is less than 0.12 seconds (3 small boxes). Widening
beyond 0.12 seconds suggests bundle branch block, ventricular origin, or drug
toxicity.
Question 3. A rhythm strip shows 4 large boxes between R waves. What is the
approximate heart rate?
,A) 60 bpm
B) 75 bpm
C) 100 bpm
D) 150 bpm
Rationale: Using the 300 method, divide 300 by the number of large boxes
between R waves: 300 ÷ 4 = 75 bpm.
Question 4. A 6-second strip contains 12 QRS complexes. What is the heart rate?
A) 60 bpm
B) 72 bpm
C) 100 bpm
D) 120 bpm
Rationale: The 6-second method multiplies the number of QRS complexes by 10:
12 × 10 = 120 bpm.
Question 5. Where is the V1 electrode placed?
A) 4th intercostal space, left sternal border
B) 4th intercostal space, right sternal border
C) 5th intercostal space, midclavicular line
D) 5th intercostal space, midaxillary line
Rationale: V1 is placed in the 4th intercostal space at the right sternal border. V2
is at the left sternal border, V4 at the midclavicular line, and V6 at the midaxillary
line.
Question 6. Which leads view the inferior wall of the heart?
A) V1–V2
B) I, aVL, V5, V6
C) II, III, aVF
D) V3–V4
Rationale: Leads II, III, and aVF are inferior leads. ST elevation in two or more of
these leads indicates an inferior wall MI.
, Question 7. Which leads are considered lateral leads?
A) V1–V2
B) I, aVL, V5, V6
C) II, III, aVF
D) V3–V4
Rationale: Lateral leads are I, aVL, V5, and V6. They view the lateral wall of the
left ventricle.
Question 8. Which leads are considered anterior leads?
A) V1–V2
B) I, aVL
C) II, III, aVF
D) V3–V4
Rationale: V3 and V4 are anterior leads. Anterior MI is associated with LAD
occlusion and carries a high mortality risk.
Question 9. Which leads are considered septal leads?
A) V5–V6
B) V1–V2
C) I, aVL
D) II, III, aVF
Rationale: V1 and V2 view the interventricular septum. Septal involvement often
accompanies anterior MI.
Question 10. Which lead is most commonly used for continuous cardiac
monitoring?
A) V1
B) Lead II
