TheoryEKG Technician
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30 free EKG Technician questions
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Cardiac Anatomy & Electrophysiology
Which structure is normally the primary pacemaker of the heart?
Correct — A. 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. -
Cardiac Anatomy & Electrophysiology
Which chambers of the heart receive blood returning to the heart?
Correct — C. 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. -
Cardiac Anatomy & Electrophysiology
The brief delay of the electrical impulse at the AV node primarily allows time for what to occur?
Correct — B. The AV node delays conduction so the atria finish contracting and fill the ventricles before ventricular contraction, optimizing stroke volume. -
Cardiac Anatomy & Electrophysiology
Which valve separates the left atrium from the left ventricle?
Correct — D. The mitral valve, with two leaflets, lies between the left atrium and left ventricle and prevents backflow during ventricular contraction. -
Cardiac Anatomy & Electrophysiology
Which side of the heart pumps blood to the lungs?
Correct — C. The right ventricle pumps deoxygenated blood through the pulmonic valve into the pulmonary arteries to the lungs for gas exchange. -
Cardiac Anatomy & Electrophysiology
Depolarization of a cardiac cell is mainly caused by the rapid influx of which ion?
Correct — A. The rapid upstroke of the cardiac action potential in working myocardium results from a fast inward sodium current through voltage-gated sodium channels. -
Cardiac Anatomy & Electrophysiology
Repolarization of the ventricular myocyte is primarily driven by the movement of which ion?
Correct — D. Repolarization occurs as potassium exits the cell, restoring the negative resting membrane potential after the depolarization and plateau phases. -
Cardiac Anatomy & Electrophysiology
The plateau phase of the ventricular action potential, which prolongs contraction, is sustained mainly by the inflow of which ion?
Correct — B. Slow inward calcium current balances potassium efflux to create the plateau, prolonging the action potential and supporting myocardial contraction. -
Cardiac Anatomy & Electrophysiology
After leaving the AV node, the impulse travels next through which structure?
Correct — A. 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. -
Cardiac Anatomy & Electrophysiology
The terminal fibers that rapidly distribute the impulse throughout the ventricular muscle are called the:
Correct — C. Purkinje fibers spread the impulse quickly across the ventricular walls so the ventricles contract in a coordinated way. -
Cardiac Anatomy & Electrophysiology
If the SA node fails, the AV junction can take over at an intrinsic rate of approximately:
Correct — B. The AV junction is a secondary (backup) pacemaker with an intrinsic rate of about 40-60 bpm, slower than the SA node's 60-100 bpm. -
Cardiac Anatomy & Electrophysiology
The intrinsic rate of a ventricular (Purkinje) escape pacemaker is approximately:
Correct — D. Ventricular escape pacemakers are the slowest backup, firing at roughly 20-40 bpm when higher pacemakers fail. -
Cardiac Anatomy & Electrophysiology
The thick middle muscular layer of the heart wall responsible for contraction is the:
Correct — C. The myocardium is the contractile muscle layer; the endocardium lines the inside and the epicardium covers the outside surface. -
Cardiac Anatomy & Electrophysiology
The double-walled sac that surrounds and protects the heart is the:
Correct — A. The pericardium encloses the heart, anchors it within the chest, and contains a small amount of fluid that reduces friction during beating. -
Cardiac Anatomy & Electrophysiology
The coronary arteries supply blood to the:
Correct — D. The coronary arteries branch from the aorta and deliver oxygenated blood to the myocardium; blockage can cause ischemia or myocardial infarction. -
Cardiac Anatomy & Electrophysiology
Most blood flow to the left ventricular myocardium through the coronary arteries occurs during which phase?
Correct — B. During systole the contracting muscle compresses the coronary vessels, so the left ventricle is mainly perfused during diastole when the muscle relaxes. -
Cardiac Anatomy & Electrophysiology
On the EKG, the P wave represents:
Correct — A. The P wave is produced by depolarization spreading through the atria, just before atrial contraction. -
Cardiac Anatomy & Electrophysiology
On the EKG, the QRS complex represents:
Correct — C. The QRS complex reflects rapid depolarization of the ventricles; atrial repolarization occurs at the same time but is hidden within the QRS. -
Cardiac Anatomy & Electrophysiology
On the EKG, the T wave represents:
Correct — B. The T wave corresponds to repolarization (electrical recovery) of the ventricles after they have contracted. -
Cardiac Anatomy & Electrophysiology
The ability of certain cardiac cells to spontaneously generate an electrical impulse is called:
Correct — D. Automaticity is the property of pacemaker cells, such as those in the SA node, to depolarize on their own without outside stimulation. -
Cardiac Anatomy & Electrophysiology
The property that allows a cardiac cell to respond to a stimulus is called:
Correct — C. Excitability, also called irritability, is the ability of a myocardial cell to depolarize in response to an electrical stimulus. -
Cardiac Anatomy & Electrophysiology
During the absolute refractory period, the cardiac cell:
Correct — A. In the absolute refractory period the cell cannot respond to any stimulus, which protects the heart from premature, sustained contractions. -
Cardiac Anatomy & Electrophysiology
The largest artery in the body, which carries oxygenated blood from the left ventricle, is the:
Correct — D. The aorta exits the left ventricle through the aortic valve and distributes oxygenated blood to the systemic circulation. -
Cardiac Anatomy & Electrophysiology
Deoxygenated blood from the upper body returns to the right atrium through the:
Correct — B. The superior vena cava drains the head, neck, and upper limbs into the right atrium; the inferior vena cava drains the lower body. -
Cardiac Anatomy & Electrophysiology
Which valve lies between the right atrium and the right ventricle?
Correct — A. The tricuspid valve has three leaflets and prevents backflow from the right ventricle into the right atrium during contraction. -
Cardiac Anatomy & Electrophysiology
Oxygenated blood returns from the lungs to the heart by way of the:
Correct — C. The pulmonary veins are unusual in carrying oxygen-rich blood; they deliver it from the lungs to the left atrium. -
Cardiac Anatomy & Electrophysiology
The ability of cardiac muscle cells to shorten and produce a heartbeat is called:
Correct — B. Contractility is the mechanical property by which myocardial fibers shorten in response to depolarization to pump blood. -
Cardiac Anatomy & Electrophysiology
The internodal pathway that conducts the impulse across the atria from the SA node toward the left atrium is the:
Correct — D. The Bachmann bundle is an interatrial conduction tract that helps spread the SA node impulse to the left atrium for coordinated atrial depolarization. -
Cardiac Anatomy & Electrophysiology
The wall that separates the right and left sides of the heart is the:
Correct — C. The interatrial and interventricular septa divide the heart into right and left sides, keeping oxygenated and deoxygenated blood separate. -
Cardiac Anatomy & Electrophysiology
The term 'systole' refers to which part of the cardiac cycle?
Correct — A. Systole is the contraction phase that ejects blood from the chambers; diastole is the relaxation and filling phase.
EKG Technician sample questions
Tap any question below to reveal the answer and a plain-English explanation.
Cardiac Anatomy & Electrophysiology Stimulation of the sympathetic nervous system on the heart typically causes the heart rate to:
A. Decrease
B. Stay exactly the same
C. Stop entirely
D. Increase ✓
Correct — D. Sympathetic stimulation releases catecholamines that speed up SA node firing and increase heart rate and contractility, the 'fight or flight' response.
Lead Placement & 12-Lead Where is the V1 chest electrode placed?
A. Fourth intercostal space at the left sternal border
B. Fourth intercostal space at the right sternal border ✓
C. Fifth intercostal space at the midclavicular line
D. Second intercostal space at the right sternal border
Correct — B. V1 is positioned in the fourth intercostal space just to the right of the sternum; V2 is the mirror position on the left.
Rhythm Recognition Which feature is characteristic of normal sinus rhythm?
A. An irregular rhythm with no P waves
B. A rate above 150 bpm
C. A wide QRS with no P waves
D. A regular rhythm with a P wave before every QRS at 60-100 bpm ✓
Correct — D. Normal sinus rhythm has upright P waves preceding each QRS, regular R-R intervals, and a rate of 60-100 bpm originating from the SA node.
Arrhythmias A premature ventricular contraction (PVC) is characterized by:
A. An early, wide, bizarre QRS with no preceding P wave ✓
B. An early narrow QRS with a normal P wave
C. A late escape beat
D. A sawtooth baseline
Correct — A. A PVC originates in the ventricle, so it appears early, has a wide and abnormally shaped QRS, and is not preceded by a related P wave.
Measurements & Intervals On standard EKG paper, each small box represents how much time horizontally?
A. 0.20 second
B. 0.10 second
C. 0.04 second ✓
D. 1.0 second
Correct — C. At the standard speed of 25 mm/sec, each 1 mm small box equals 0.04 second; five small boxes make one large box of 0.20 second.
Artifact & Troubleshooting A jagged, irregular, fuzzy baseline caused by patient shivering or tremor is called:
A. Wandering baseline
B. Sixty-cycle interference
C. A pacemaker spike
D. Somatic (muscle) tremor artifact ✓
Correct — D. Muscle movement produces erratic spikes superimposed on the tracing; warming the patient or repositioning often reduces this somatic artifact.
Equipment The disposable adhesive sensors that attach to the patient's skin to detect electrical activity are called:
A. Lead wires
B. Electrodes ✓
C. Calipers
D. Defibrillator pads only
Correct — B. Electrodes pick up the heart's electrical signals from the skin; the lead wires then carry those signals to the EKG machine.
Patient Care & Safety Before performing an EKG, the technician should first:
A. Begin recording immediately to save time
B. Verify the patient's identity using two identifiers ✓
C. Remove all electrodes from a previous patient's chart
D. Interpret the rhythm before connecting leads
Correct — B. Confirming identity with two identifiers (such as name and date of birth) ensures the EKG is performed on and recorded for the correct patient.
About the EKG Technician test
The EKG Technician measures the Nursing/Medical knowledge you'll actually rely on — tested the way the real exam asks it, not with trick questions. Practising real EKG Technician-style questions, then sitting a full timed mock exam, is the fastest way to walk in knowing you'll pass.
You will be tested on
- Safe and effective care environment
- Health promotion and maintenance
- Psychosocial and physiological integrity
- Pharmacology, infection control and patient safety
How TheoryPractice helps you pass
- Real exam-style questions with instant, detailed explanations
- Full timed mock exams that mirror the real test format
- Flashcards & quiz modes from the same question bank
- Progress tracking so you know exactly when you're ready
Topics in this question bank
Safe and effective care environment
Health promotion and maintenance
Psychosocial and physiological integrity
Pharmacology, infection control and patient safety
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