EKG Technician Exam Questions & Answers 2026 (1–10)

Question 1

Which structure is normally the primary pacemaker of the heart?

TheoryPractice · Accepted Answer

The sinoatrial (SA) node. The SA node in the right atrium has the fastest intrinsic rate (about 60-100 beats per minute) and therefore sets the normal heart rhythm, called sinus rhythm.

Question 2

Which chambers of the heart receive blood returning to the heart?

TheoryPractice · Accepted Answer

The atria. The atria are the upper receiving chambers; the right atrium receives deoxygenated blood from the body and the left atrium receives oxygenated blood from the lungs.

Question 3

The brief delay of the electrical impulse at the AV node primarily allows time for what to occur?

TheoryPractice · Accepted Answer

Ventricular filling as the atria contract. The AV node delays conduction so the atria finish contracting and fill the ventricles before ventricular contraction, optimizing stroke volume.

Question 4

Which valve separates the left atrium from the left ventricle?

TheoryPractice · Accepted Answer

The mitral (bicuspid) valve. The mitral valve, with two leaflets, lies between the left atrium and left ventricle and prevents backflow during ventricular contraction.

Question 5

Which side of the heart pumps blood to the lungs?

TheoryPractice · Accepted Answer

The right side. The right ventricle pumps deoxygenated blood through the pulmonic valve into the pulmonary arteries to the lungs for gas exchange.

Question 6

Depolarization of a cardiac cell is mainly caused by the rapid influx of which ion?

TheoryPractice · Accepted Answer

Sodium. The rapid upstroke of the cardiac action potential in working myocardium results from a fast inward sodium current through voltage-gated sodium channels.

Question 7

Repolarization of the ventricular myocyte is primarily driven by the movement of which ion?

TheoryPractice · Accepted Answer

Potassium leaving the cell. Repolarization occurs as potassium exits the cell, restoring the negative resting membrane potential after the depolarization and plateau phases.

Question 8

The plateau phase of the ventricular action potential, which prolongs contraction, is sustained mainly by the inflow of which ion?

TheoryPractice · Accepted Answer

Calcium. Slow inward calcium current balances potassium efflux to create the plateau, prolonging the action potential and supporting myocardial contraction.

Question 9

After leaving the AV node, the impulse travels next through which structure?

TheoryPractice · Accepted Answer

The bundle of His. From the AV node the impulse passes into the bundle of His, then divides into the right and left bundle branches, and finally reaches the Purkinje fibers.

Question 10

The terminal fibers that rapidly distribute the impulse throughout the ventricular muscle are called the:

TheoryPractice · Accepted Answer

Purkinje fibers. Purkinje fibers spread the impulse quickly across the ventricular walls so the ventricles contract in a coordinated way.

EKG Technician Exam Questions & Answers 2026 (1–10)

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