NHA Certified EKG Technician (CET) Exam Prep 2026 – Complete Practice Questions, EKG Strip Analysis & Detailed Clinical Rationales (Pass on First Try)

NHA Certified EKG Technician (CET) Exam – Complete
Practice Questions & Rationales
Welcome to your comprehensive practice test bank for the NHA Certified EKG
Technician (CET) Exam. The actual exam consists of 120 total items (100 scored + 20
pretest) with a 2-hour time limit and a passing score of 390 on a 200-500 scale. The
exam is divided into three weighted domains:


Domain Weight

Safety & Compliance 32%

EKG Acquisition 44%

EKG Analysis & Interpretation 24%




Section 1: Cardiac Anatomy & Physiology (Questions 1-30)
Question 1
Which chamber of the heart pumps oxygenated blood into the systemic circulation?

A. Right atrium
B. Right ventricle
C. Left atrium
D. Left ventricle

*Correct Answer: D. Left ventricle. *

Rationale: The left ventricle pumps oxygen-rich blood through the aorta to the entire body.
The right ventricle pumps deoxygenated blood to the lungs, and the atria receive blood
returning to the heart.

,Question 2
The sinoatrial (SA) node is commonly known as the:

A. Secondary pacemaker
B. Bundle branch
C. Natural pacemaker
D. AV junction

*Correct Answer: C. Natural pacemaker. *

Rationale: The SA node, located in the right atrium, initiates electrical impulses and
normally controls the heart rhythm. It is the heart's primary pacemaker.




Question 3
What is the normal resting heart rate for adults?

A. 20–40 bpm
B. 60–100 bpm
C. 100–120 bpm
D. 120–140 bpm

*Correct Answer: B. 60–100 bpm. *

Rationale: The normal resting heart rate for adults is 60–100 beats per minute. The SA
node typically discharges at this rate.




Question 4
What is the normal intrinsic firing rate of the AV node?

A. 20–40 bpm
B. 40–60 bpm
C. 60–100 bpm
D. 100–120 bpm

*Correct Answer: B. 40–60 bpm. *

,Rationale: If the SA node fails, the AV node can take over as a backup pacemaker at an
intrinsic rate of 40–60 bpm.




Question 5
What is the normal intrinsic firing rate of the Purkinje fibers?

A. 20–40 bpm
B. 40–60 bpm
C. 60–100 bpm
D. 100–120 bpm

*Correct Answer: A. 20–40 bpm. *

Rationale: The Purkinje fibers serve as a tertiary pacemaker with an intrinsic rate of 20–40
bpm, providing a backup if both the SA and AV nodes fail.




Question 6
Which valve prevents the backflow of blood from the left ventricle into the left atrium?

A. Tricuspid valve
B. Pulmonary valve
C. Mitral valve
D. Aortic valve

*Correct Answer: C. Mitral valve. *

Rationale: The mitral (bicuspid) valve separates the left atrium from the left ventricle and
prevents backflow of blood into the atrium during ventricular contraction.




Question 7
Which valve prevents the backflow of blood from the right ventricle into the right
atrium?

, A. Tricuspid valve
B. Pulmonary valve
C. Mitral valve
D. Aortic valve

*Correct Answer: A. Tricuspid valve. *

Rationale: The tricuspid valve separates the right atrium from the right ventricle and
prevents backflow during ventricular contraction.




Question 8
Deoxygenated blood flows from the right ventricle to the lungs through which vessel?

A. Aorta
B. Vena cava
C. Pulmonary artery
D. Pulmonary vein

*Correct Answer: C. Pulmonary artery. *

Rationale: The pulmonary artery carries deoxygenated blood from the right ventricle to the
lungs for oxygenation. It is the only artery that carries deoxygenated blood.




Question 9
Oxygenated blood returns to the left atrium from the lungs through which vessels?

A. Pulmonary arteries
B. Pulmonary veins
C. Aorta
D. Vena cava

*Correct Answer: B. Pulmonary veins. *

Rationale: The pulmonary veins carry oxygenated blood from the lungs back to the left
atrium. They are the only veins that carry oxygenated blood.