Certified EKG Technician (CET) Exam — Questions and Answers

Question 1: What is the normal duration of the QRS complex in a healthy adult?

Less than 0.04 seconds
0.20 to 0.24 seconds
0.06 to 0.10 seconds (Correct answer)
0.12 to 0.16 seconds

Correct answer: 0.06 to 0.10 seconds

The normal QRS duration is 0.06 to 0.10 seconds, indicating rapid and synchronized ventricular depolarization.

Question 2: When using the 6-second strip method to calculate heart rate, the number of R waves counted within the strip is multiplied by which number?

15
10 (Correct answer)
20
6

Correct answer: 10

A standard 6-second strip multiplied by 10 gives the number of beats per minute. This method is especially useful for irregular rhythms because it averages the rate over a defined time interval.

Question 3: Which step in electrode site preparation BEST reduces skin impedance and improves EKG signal quality while also supporting infection control?

Gently abrading the skin with a dry gauze pad after cleaning with alcohol (Correct answer)
Applying petroleum jelly to the electrode site before placement
Leaving the site to air dry for at least 10 minutes after cleaning
Shaving all chest hair with a multi-use razor shared between patients

Correct answer: Gently abrading the skin with a dry gauze pad after cleaning with alcohol

Light abrasion with gauze removes dead skin cells and sebum, lowering electrical impedance for a cleaner tracing. Alcohol is applied first for antisepsis; disposable razors should be single-patient-use only to prevent cross-contamination.

Question 4: During a cardiac stress test, what is the primary reason for monitoring the ST segment on the EKG?

To assess QT interval prolongation
To detect exercise-induced myocardial ischemia (Correct answer)
To evaluate atrial flutter patterns
To measure heart rate recovery time

Correct answer: To detect exercise-induced myocardial ischemia

ST segment depression during exercise is the hallmark EKG finding that indicates myocardial ischemia due to inadequate coronary blood flow.

Question 5: What is the importance of Stress Testing & Holter Monitoring in EKG certification?

It is crucial for understanding the heart's electrical activity and ensuring accurate results. (Correct answer)
It is irrelevant for proper diagnosis.
It only applies to advanced medical procedures.
It has no impact on patient outcomes.

Correct answer: It is crucial for understanding the heart's electrical activity and ensuring accurate results.

Stress Testing and Holter Monitoring are vital because they provide dynamic insights into the heart's electrical activity under various conditions that a resting EKG might miss. Stress tests reveal how the heart performs under exertion, while Holter monitoring captures intermittent arrhythmias over extended periods. This comprehensive data is crucial for ensuring accurate diagnostic results and a thorough understanding of cardiac function.

Question 6: A patient on digoxin therapy has an EKG showing a downsloping ST depression described as 'scooped' or 'Salvador Dali moustache' morphology. What does this finding represent?

Acute anterolateral STEMI
Digoxin effect (digitalis effect) (Correct answer)
Third-degree AV block
Hypokalemia-induced T-wave changes

Correct answer: Digoxin effect (digitalis effect)

The characteristic downsloping, scooped ST-segment depression — often compared to a Salvador Dali moustache — is a classic EKG manifestation of digoxin effect (not toxicity). It reflects altered ventricular repolarization caused by the drug's action and does not necessarily indicate toxicity or ischemia.

Question 7: Which of the following ECG waveforms best exemplifies repolarization? 10.

P wave
T wave (Correct answer)
QRS complex
RS wave

Correct answer: T wave

On a standard electrocardiogram (ECG), the T wave represents the repolarization of the ventricles. This electrical recovery phase signifies that the ventricular muscle cells are relaxing and recharging, preparing for the next electrical impulse and subsequent contraction. The P wave represents atrial depolarization, and the QRS complex represents ventricular depolarization.

Question 8: Which EKG filter setting is used to reduce muscle artifact and motion noise while potentially affecting high-frequency components?

150 Hz low-pass filter
60 Hz notch filter
40 Hz low-pass filter (Correct answer)
0.05 Hz high-pass filter

Correct answer: 40 Hz low-pass filter

The 40 Hz low-pass filter reduces high-frequency muscle noise but may slightly reduce the amplitude of sharp waveform components like the QRS.

Question 9: Why is Electrode Placement & Lead Systems essential for EKG technicians?

It is only used for educational purposes.
It is irrelevant to the EKG testing process.
It is only relevant for cardiologists.
It ensures accurate EKG readings and proper diagnosis of heart conditions. (Correct answer)

Correct answer: It ensures accurate EKG readings and proper diagnosis of heart conditions.

For EKG technicians, mastering electrode placement and lead systems is essential because they are directly responsible for acquiring high-quality EKG tracings. Accurate placement ensures that the readings are reliable and free from artifact, allowing physicians to make correct diagnoses of heart conditions. This skill is fundamental to their role in providing valuable diagnostic information and ensuring patient safety.

Question 10: After completing a 48-hour Holter recording, the patient returns the device. The technician notices the electrode in lead V5 position had poor skin contact for the last 12 hours, producing significant artifact. What is the most appropriate next step?

Report the full 48 hours of data as valid since two leads remained clean
Discard the entire recording and repeat the Holter immediately
Re-apply the electrode and extend the recording by another 12 hours to compensate
Note the artifact in the report, analyze the remaining clean lead data, and flag the affected time period for the interpreting physician (Correct answer)

Correct answer: Note the artifact in the report, analyze the remaining clean lead data, and flag the affected time period for the interpreting physician

Partial artifact does not invalidate an entire Holter study. The technician should document which channels and time periods were affected by poor contact, analyze the usable data from the remaining leads, and clearly communicate these limitations to the interpreting physician.

Question 11: When placing precordial leads for a 12-lead EKG, where is the V1 electrode positioned?

Fourth intercostal space, right sternal border (Correct answer)
Fifth intercostal space, midclavicular line
Second intercostal space, right sternal border
Fourth intercostal space, left sternal border

Correct answer: Fourth intercostal space, right sternal border

V1 is placed at the fourth intercostal space along the RIGHT sternal border. V2 mirrors it on the left sternal border. This pair straddles the sternum and provides a septal view of the heart.

Question 12: Which EKG finding is characteristic of Wolff-Parkinson-White (WPW) syndrome?

ST elevation in contiguous leads
Delta wave with shortened PR interval (Correct answer)
Peaked T waves with widened QRS
Prolonged PR interval with dropped beats

Correct answer: Delta wave with shortened PR interval

WPW syndrome is identified by a delta wave (slurred upstroke of the QRS), shortened PR interval, and widened QRS complex due to an accessory pathway.

Question 13: What is the primary purpose of an Implantable Cardioverter-Defibrillator (ICD)?

To control rapid atrial fibrillation with overdrive pacing
To continuously monitor and record heart rhythms for later analysis
To maintain a minimum heart rate via backup pacing only
To detect and terminate life-threatening ventricular arrhythmias with a shock (Correct answer)

Correct answer: To detect and terminate life-threatening ventricular arrhythmias with a shock

An ICD continuously monitors cardiac rhythm and delivers an internal defibrillation shock to terminate ventricular fibrillation or ventricular tachycardia, preventing sudden cardiac death.

Question 14: What is the recommended action when somatic tremor artifact is identified on an EKG strip?

Switch to half sensitivity
Increase the paper speed
Continue recording and note artifact in the report
Ask the patient to hold their breath and relax muscles, then re-record (Correct answer)

Correct answer: Ask the patient to hold their breath and relax muscles, then re-record

Having the patient relax, warm the room, and ask them to hold their breath momentarily can eliminate somatic tremor artifact for a clean recording.

Question 15: What is the correct technique for locating the V1 electrode position on a patient?

Measure 4 cm from the center of the sternum on the right side
Palpate the second intercostal space at the right sternal border, then count down two spaces (Correct answer)
Estimate based on visual chest landmarks only
Place it at the midclavicular line on the right

Correct answer: Palpate the second intercostal space at the right sternal border, then count down two spaces

The standard technique is to palpate the sternal angle (angle of Louis), then locate the second rib and second intercostal space, counting down to the fourth intercostal space at the right sternal border.

Question 16: An EKG tracing shows ST-segment elevation in leads V1 through V4. Which region of the myocardium is most likely affected?

Posterior wall
Inferior wall
Anterior wall (Correct answer)
Lateral wall

Correct answer: Anterior wall

Leads V1–V4 are the precordial leads that overlie the anterior surface of the heart. ST elevation in these leads suggests anterior wall myocardial injury or infarction, most commonly due to occlusion of the left anterior descending (LAD) artery.

Question 17: A patient's rhythm strip shows a progressively lengthening PR interval followed by a dropped QRS complex, then the cycle repeats. What is this rhythm?

Second-degree AV block Type II
First-degree AV block
Third-degree AV block
Second-degree AV block Type I (Wenckebach) (Correct answer)

Correct answer: Second-degree AV block Type I (Wenckebach)

Progressive PR prolongation culminating in a non-conducted P wave with a repeating cycle is the defining pattern of Mobitz Type I (Wenckebach) block.

Question 18: During which phase of the cardiac cycle do the ventricles fill with blood passively?

Ejection phase
Diastole (Correct answer)
Isovolumetric contraction
Systole

Correct answer: Diastole

During diastole the ventricles relax and fill passively with blood flowing from the atria through the open AV valves.

Question 19: What is the standard paper speed used for a resting 12-lead EKG in the United States?

50 mm/sec
25 mm/sec (Correct answer)
15 mm/sec
10 mm/sec

Correct answer: 25 mm/sec

The standard paper speed for a resting 12-lead EKG in the US is 25 mm/sec, making each small box equal to 0.04 seconds.

Question 20: A rhythm strip shows no visible P waves and an irregularly irregular ventricular response. What is the most likely rhythm?

Ventricular tachycardia
Atrial fibrillation (Correct answer)
Junctional rhythm
Atrial flutter

Correct answer: Atrial fibrillation

Atrial fibrillation is characterized by chaotic atrial activity with no discrete P waves, a fibrillatory baseline, and an irregularly irregular ventricular response. Atrial flutter shows sawtooth flutter waves at a regular rate.

Question 21: Which of the following patient conditions requires the EKG technician to document a modified electrode placement?

Diabetes
Obesity
Hypertension
Amputation of a limb (Correct answer)

Correct answer: Amputation of a limb

If a limb is amputated, the electrode must be placed on the stump or the closest available site, and the modification must be clearly documented on the tracing.

Question 22: What is the importance of Electrode Placement & Lead Systems in EKG certification?

It is irrelevant for proper diagnosis.
It has no impact on patient outcomes.
It is crucial for understanding the heart's electrical activity and ensuring accurate results. (Correct answer)
It only applies to advanced medical procedures.

Correct answer: It is crucial for understanding the heart's electrical activity and ensuring accurate results.

Correct electrode placement and lead systems are paramount in EKG certification because they directly determine how the heart's electrical signals are captured. Precise placement ensures that the EKG machine records accurate and undistorted waveforms, which are crucial for correctly interpreting the heart's electrical activity. This accuracy is vital for a proper diagnosis and understanding the patient's cardiac health.

Question 23: Which statement about disposable EKG electrodes is correct?

They contain a conductive gel that maintains good skin contact (Correct answer)
They do not require skin preparation before placement
They should be stored in a warm environment to extend shelf life
They can be reused on the same patient if removed carefully

Correct answer: They contain a conductive gel that maintains good skin contact

Disposable EKG electrodes contain a conductive gel that reduces skin-electrode impedance and ensures good electrical contact for accurate signal acquisition.

Question 24: How should an EKG technician respond if a patient refuses the procedure?

Attempt to perform the EKG without the patient's knowledge
Document the refusal, inform the ordering provider, and respect the patient's decision (Correct answer)
Call security to assist
Proceed anyway to avoid delays in care

Correct answer: Document the refusal, inform the ordering provider, and respect the patient's decision

Patient autonomy must be respected; the technician documents the refusal, notifies the ordering provider, and does not perform the procedure against the patient's wishes.

Question 25: In a second-degree AV block Type II (Mobitz II), what is the expected pattern of PR intervals before a dropped QRS?

Constant PR intervals with sudden dropped QRS (Correct answer)
Variable PR intervals with irregular rhythm
Absent P waves throughout
Progressively lengthening PR intervals

Correct answer: Constant PR intervals with sudden dropped QRS

Mobitz Type II block shows constant PR intervals with sudden unexpected failure of conduction, resulting in a dropped QRS without prior PR prolongation.

Question 26: How does Heart Rate & Rhythm Analysis affect treatment decisions?

It has no impact on treatment decisions.
It is used only for diagnostic purposes.
It does not contribute to treatment planning.
It provides insights that guide the selection of appropriate interventions. (Correct answer)

Correct answer: It provides insights that guide the selection of appropriate interventions.

The findings from heart rate and rhythm analysis directly influence treatment decisions. For instance, a dangerously slow heart rate might necessitate a pacemaker, while a rapid, irregular rhythm could require antiarrhythmic medication or cardioversion. These insights are crucial for guiding clinicians in selecting the most effective and appropriate interventions to manage the patient's cardiac condition, ensuring targeted and beneficial care.

Question 27: A technician notices lead III has an inverted P wave and upright QRS. Which electrode misplacement is most likely?

V1 and V2 electrodes are swapped
Right arm and left arm electrodes are reversed (Correct answer)
Left arm and left leg electrodes are reversed
Right leg and left leg electrodes are reversed

Correct answer: Right arm and left arm electrodes are reversed

Reversal of the right arm and left arm electrodes causes lead III to display characteristics normally seen in other leads, including P-wave inversion.

Question 28: An EKG cable set has visible dried secretions on it after use. What is the correct next step?

Wipe with a facility-approved disinfectant wipe and allow full contact time before reuse (Correct answer)
Rinse the cables under running water and immediately reuse them
Place the cables in an autoclave for sterilization
Discard the cables as biohazardous waste

Correct answer: Wipe with a facility-approved disinfectant wipe and allow full contact time before reuse

Reusable EKG cables must be cleaned with an EPA-registered, facility-approved disinfectant and allowed the full recommended contact (dwell) time to inactivate pathogens. Autoclaving damages the cables, and discarding reusable equipment is unnecessary if proper disinfection is performed.

Question 29: Name the location of V2 that is correct:

4th left intercostal space
4th right intercostal space (Correct answer)
5th left intercostal space
5th right intercostal space

Correct answer: 4th right intercostal space

Lead V2 is correctly placed in the fourth intercostal space, just to the right of the sternum. This precise anatomical placement is part of the standard 12-lead EKG system, ensuring consistent and accurate recording of the heart's electrical activity. Proper lead placement is fundamental for reliable EKG interpretation.

Question 30: Which of the following best describes the Bruce Protocol used in exercise stress testing?

A supine leg-press protocol designed for patients who cannot walk
A pharmacologic stress test using adenosine infused at a fixed rate
A bicycle ergometer test that increases pedaling resistance every 2 minutes
A treadmill protocol with stages that increase speed and incline every 3 minutes (Correct answer)

Correct answer: A treadmill protocol with stages that increase speed and incline every 3 minutes

The Bruce Protocol is the most widely used treadmill exercise stress test, consisting of successive 3-minute stages where both belt speed and incline (grade) increase, progressively raising the patient's workload and heart rate.

Question 31: A wandering baseline artifact on an EKG is most likely caused by:

Incorrect lead placement
60 Hz electrical interference
Electrode movement or poor skin preparation (Correct answer)
Improper machine calibration

Correct answer: Electrode movement or poor skin preparation

Wandering baseline is most often caused by electrode movement, poor adhesion, or inadequate skin preparation such as not cleaning the electrode site.

Question 32: When performing a 12-lead EKG on a pediatric patient, which adaptation is most appropriate?

Skip the precordial leads to reduce patient stress
Use smaller pediatric electrodes to fit the smaller chest and limb size (Correct answer)
Use double standard sensitivity for all leads
Use adult-sized electrodes to ensure better contact

Correct answer: Use smaller pediatric electrodes to fit the smaller chest and limb size

Pediatric patients require smaller electrodes designed for their body size to ensure proper electrode-to-skin contact and accurate waveform capture.

Question 33: When blood flow to the heart muscle is stopped or abruptly reduced for long enough to result in cell death, myocardial infarction occurs.

TRUE (Correct answer)
FALSE

Correct answer: TRUE

This statement is TRUE. Myocardial infarction, commonly known as a heart attack, occurs when blood flow to a section of the heart muscle is severely reduced or completely blocked. This prolonged lack of oxygen and nutrients leads to the irreversible death of heart muscle cells, which is the defining characteristic of a myocardial infarction.

Question 34: During a treadmill stress test, which EKG change is considered a positive finding indicating myocardial ischemia?

ST-segment depression of 2 mm that is horizontal or downsloping (Correct answer)
T-wave inversion of 1 mm in V1
Sinus tachycardia reaching 85% of the maximum predicted heart rate
Occasional premature atrial contractions during peak exercise

Correct answer: ST-segment depression of 2 mm that is horizontal or downsloping

Horizontal or downsloping ST-segment depression of ≥1 mm (and especially ≥2 mm) during exercise is the classic EKG sign of exercise-induced myocardial ischemia, reflecting subendocardial oxygen demand that outpaces supply.

Question 35: What is the normal duration of the PR interval on an EKG?

0.06 to 0.10 seconds
0.36 to 0.44 seconds
0.20 to 0.40 seconds
0.12 to 0.20 seconds (Correct answer)

Correct answer: 0.12 to 0.20 seconds

The PR interval normally measures 0.12 to 0.20 seconds and represents the time from atrial depolarization to the onset of ventricular depolarization.

Question 36: Which EKG lead is best for evaluating atrial rhythm and identifying P waves?

Lead V6
Lead II (Correct answer)
Lead V1
Lead aVR

Correct answer: Lead II

Lead II provides the best view of P waves because its axis is nearly parallel to the normal atrial depolarization vector.

Question 37: Why is accurate Safety & Infection Control Protocols essential for patient care?

It is necessary for assessing heart function accurately.
It is mainly used in emergency situations.
It is necessary for proper patient diagnosis and care. (Correct answer)
It is irrelevant for overall patient well-being.

Correct answer: It is necessary for proper patient diagnosis and care.

Accurate adherence to Safety & Infection Control Protocols is paramount for protecting patients from harm and preventing healthcare-associated infections. By ensuring a safe environment, these protocols allow for the reliable performance of diagnostic tests, which are essential for proper diagnosis and the delivery of effective, uninterrupted patient care. This directly contributes to overall patient well-being.

Question 38: How does Safety & Infection Control Protocols contribute to patient safety?

It is only necessary for physical tasks.
It has no impact on patient safety.
It only applies to theoretical knowledge.
It helps identify potential risks and ensures accurate treatment. (Correct answer)

Correct answer: It helps identify potential risks and ensures accurate treatment.

Safety & Infection Control Protocols directly contribute to patient safety by minimizing the risk of harm, such as infections or equipment-related incidents, during EKG procedures. By establishing clear guidelines for hygiene, equipment handling, and emergency response, these protocols create a secure environment. This allows for reliable diagnostic testing, which then informs accurate treatment decisions, further safeguarding the patient's well-being.

Question 39: Using the sequence method (300-150-100-75-60-50), an R wave falls on a heavy black line and the next R wave falls between the fourth and fifth lines of the sequence. What is the estimated heart rate?

Between 75 and 100 bpm
Between 60 and 75 bpm (Correct answer)
Between 50 and 60 bpm
Between 100 and 150 bpm

Correct answer: Between 60 and 75 bpm

The fourth heavy line corresponds to 75 bpm and the fifth to 60 bpm, so an R wave falling between them indicates a rate between 60 and 75 bpm.

Question 40: During continuous monitoring, you observe a sudden onset of regular narrow-complex tachycardia at 170 bpm that terminates abruptly with a vagal maneuver. What is the most likely rhythm?

Sinus tachycardia
Ventricular tachycardia
Atrial flutter
AV nodal reentrant tachycardia (AVNRT) (Correct answer)

Correct answer: AV nodal reentrant tachycardia (AVNRT)

Sudden onset and termination with vagal maneuvers in a regular narrow-complex tachycardia is classic for AVNRT, the most common paroxysmal SVT.

Question 41: What is the primary advantage of an event monitor over a standard 24-hour Holter monitor?

It can record over weeks to capture infrequent symptoms (Correct answer)
It automatically delivers therapy for detected arrhythmias
It measures cardiac output during recording
It provides continuous 12-lead monitoring

Correct answer: It can record over weeks to capture infrequent symptoms

Event monitors can be worn for weeks or months, making them ideal for capturing arrhythmias that occur too infrequently to be caught in a 24-hour Holter recording.

Question 42: An EKG shows absent P waves with an irregularly irregular rhythm. What is the most likely interpretation?

Atrial fibrillation (Correct answer)
Atrial flutter
Ventricular tachycardia
Sinus arrhythmia

Correct answer: Atrial fibrillation

Atrial fibrillation is defined by absent P waves replaced by fibrillatory waves and an irregularly irregular ventricular response.

Question 43: What does the presence of Q waves in leads V1 through V4 on an EKG most likely indicate?

Posterior myocardial infarction
Pericarditis
Right ventricular hypertrophy
Anterior myocardial infarction (Correct answer)

Correct answer: Anterior myocardial infarction

Pathological Q waves in the anterior leads V1-V4 indicate prior anterior wall myocardial infarction with transmural necrosis.

Question 44: During a 12-lead ECG recording, the patient develops muscle tremors in the left arm. Which leads will most likely show artifact?

Leads II and III
Leads I and aVL (Correct answer)
Leads V1 and V2
Leads V5 and V6

Correct answer: Leads I and aVL

The left arm electrode contributes to leads I and aVL, so tremor artifact will primarily affect those leads.

Question 45: When performing a 12-lead EKG, where should the V4 electrode be placed?

Fifth intercostal space, left midaxillary line
Fifth intercostal space, left anterior axillary line
Fourth intercostal space, left sternal border
Fifth intercostal space, midclavicular line (Correct answer)

Correct answer: Fifth intercostal space, midclavicular line

V4 is placed at the fifth intercostal space at the left midclavicular line.

Question 46: Which precordial lead is positioned at the fourth intercostal space to the right of the sternum?

V1 (Correct answer)
V3
V4
V2

Correct answer: V1

V1 is placed at the fourth intercostal space at the right sternal border.

Question 47: A patient wearing a Holter monitor reports feeling palpitations at 3:15 PM but the diary entry is missing. What feature of the Holter system helps correlate symptoms?

The event marker button pressed by the patient (Correct answer)
Built-in pulse oximetry
Physician remote access alerts
Automatic blood pressure readings

Correct answer: The event marker button pressed by the patient

The event marker button allows patients to flag the exact time they experience symptoms, enabling correlation with the recorded rhythm strip.

Question 48: A patient's stress test EKG shows 2 mm horizontal ST depression in leads V4-V6 at peak exercise. What does this finding most likely indicate?

Normal physiologic response to exercise
Electrolyte imbalance from sweating
Right ventricular hypertrophy
Significant myocardial ischemia in the lateral wall (Correct answer)

Correct answer: Significant myocardial ischemia in the lateral wall

Horizontal ST depression of 2 mm or more during exercise strongly suggests significant myocardial ischemia in the territory supplied by the affected coronary artery.

Question 49: What is the target heart rate formula most commonly used to determine adequate stress during an exercise stress test?

200 minus the patient's age
220 minus the patient's age (Correct answer)
180 minus the patient's resting heart rate
250 minus half the patient's age

Correct answer: 220 minus the patient's age

The age-predicted maximum heart rate is calculated as 220 minus age, and the target is typically 85% of this value for a diagnostic test.

Question 50: How does Stress Testing & Holter Monitoring affect treatment decisions?

It does not contribute to treatment planning.
It has no impact on treatment decisions.
It is used only for diagnostic purposes.
It provides insights that guide the selection of appropriate interventions. (Correct answer)

Correct answer: It provides insights that guide the selection of appropriate interventions.

Stress Testing and Holter Monitoring significantly affect treatment decisions by providing detailed insights into the heart's function and rhythm. The data gathered, such as the presence of ischemia or specific arrhythmias, guides clinicians in selecting the most appropriate interventions. This can range from medication adjustments to recommendations for lifestyle changes or advanced cardiac procedures, ensuring targeted and effective treatment.

Question 51: What is the importance of Safety & Infection Control Protocols in EKG certification?

It has no impact on patient outcomes.
It only applies to advanced medical procedures.
It is crucial for understanding the heart's electrical activity and ensuring accurate results. (Correct answer)
It is irrelevant for proper diagnosis.

Correct answer: It is crucial for understanding the heart's electrical activity and ensuring accurate results.

While primarily focused on patient and staff well-being, adherence to Safety & Infection Control Protocols indirectly supports accurate EKG results. By preventing complications like infections or adverse events, these protocols ensure a stable testing environment. This stability is essential for obtaining clear, artifact-free EKG readings, which are fundamental for accurately understanding the heart's electrical activity and making reliable diagnoses.

Question 52: In Einthoven's triangle, Lead I measures the potential difference between which two electrodes?

Left arm (positive) and left leg (negative)
Left leg (positive) and right arm (negative)
Right arm (positive) and left leg (negative)
Left arm (positive) and right arm (negative) (Correct answer)

Correct answer: Left arm (positive) and right arm (negative)

Lead I records the voltage difference from the right arm (negative) to the left arm (positive).

Question 53: An EKG rhythm strip shows upright, uniform P waves before every QRS complex, a PR interval of 0.16 seconds, a regular R-R interval, and a rate of 78 bpm. This rhythm is most consistent with which of the following?

Sinus bradycardia
Accelerated junctional rhythm
First-degree AV block
Normal sinus rhythm (Correct answer)

Correct answer: Normal sinus rhythm

Normal sinus rhythm has a rate of 60–100 bpm, upright and uniform P waves preceding each QRS, a PR interval of 0.12–0.20 seconds, and a regular rhythm — all criteria met here.

Question 54: Which group of leads represents the lateral wall of the left ventricle?

aVR, V1, and V2
I, aVL, V5, and V6 (Correct answer)
II, III, and aVF
V1, V2, V3, and V4

Correct answer: I, aVL, V5, and V6

Leads I, aVL, V5, and V6 provide views of the lateral wall of the left ventricle.

Question 55: Which EKG wave represents atrial depolarization?

QRS complex
U wave
T wave
P wave (Correct answer)

Correct answer: P wave

The P wave on an EKG represents the electrical depolarization spreading through the right and left atria.

Question 56: Following complaints of weakness and overall malaise, a patient is put on the heart monitor. What kind of rhythm is this?

atrial fibrillation
accelerated idioventricular rhythm (Correct answer)
ventricular fibrillation
sinus arrest

Correct answer: accelerated idioventricular rhythm

Accelerated idioventricular rhythm (AIVR) is characterized by a ventricular rate between 40-100 bpm, wide QRS complexes, and no consistent relationship between P waves and QRS complexes (or absent P waves). It often occurs in the setting of myocardial ischemia or reperfusion. The symptoms of weakness and malaise are consistent with a slower ventricular rhythm that may not adequately perfuse the body.

Question 57: What is the correct paper speed used for a standard resting 12-lead EKG?

10 mm/sec
50 mm/sec
25 mm/sec (Correct answer)
100 mm/sec

Correct answer: 25 mm/sec

The standard paper speed for a resting 12-lead EKG is 25 mm/sec. At this speed, each small square (1 mm) represents 0.04 seconds and each large square (5 mm) represents 0.20 seconds. Some countries use 50 mm/sec for pediatric tracings, but 25 mm/sec is the universal standard for adults.

Question 58: Why is accurate Electrode Placement & Lead Systems essential for patient care?

It is mainly used in emergency situations.
It is irrelevant for overall patient well-being.
It is necessary for assessing heart function accurately.
It is necessary for proper patient diagnosis and care. (Correct answer)

Correct answer: It is necessary for proper patient diagnosis and care.

Accurate electrode placement and lead systems are essential for patient care because they directly impact the reliability of EKG readings, which are foundational for diagnosis. A correct diagnosis guides appropriate treatment plans and interventions, ensuring the patient receives the most effective and timely care. Conversely, incorrect placement can lead to misdiagnosis, delayed treatment, or even unnecessary procedures, compromising patient well-being and safety.

Question 59: When should an EKG technician replace disposable electrodes during a patient visit?

Only if the patient requests it
If the electrode loses adhesion or the gel dries out before recording (Correct answer)
Electrodes should never be replaced mid-session
After every 30 minutes of monitoring

Correct answer: If the electrode loses adhesion or the gel dries out before recording

Electrodes should be replaced if they lose adhesion or dry out, as poor electrode-skin contact leads to artifact and inaccurate recordings.

Question 60: Muscle tremor artifact on an EKG most closely resembles which rhythm disturbance?

Supraventricular tachycardia
Ventricular fibrillation (Correct answer)
Atrial flutter
Atrial fibrillation

Correct answer: Ventricular fibrillation

Muscle tremor artifact produces irregular, rapid baseline fluctuations that can mimic the chaotic appearance of ventricular fibrillation.

Question 61: Why is documentation important in Safety & Infection Control Protocols?

It provides a legal and medical record of diagnostic results. (Correct answer)
It is not necessary unless requested.
It is only used for billing purposes.
It is irrelevant to patient care.

Correct answer: It provides a legal and medical record of diagnostic results.

Documentation within Safety & Infection Control Protocols is crucial for maintaining a verifiable record of compliance and any incidents. While the answer mentions "diagnostic results," proper documentation of safety measures ensures that the environment for obtaining those results is controlled and safe. This record supports accountability, quality assurance, and provides a legal trail, indirectly contributing to the reliability of the diagnostic process.

Question 62: The term "ventricular diastole" means ventricular:

Contraction
Relaxation
Filling time (Correct answer)
Pressure ratio

Correct answer: Filling time

Ventricular diastole refers to the period when the ventricles are relaxed and actively filling with blood from the atria. While relaxation is a key component, the primary physiological event during diastole is the filling of the ventricles. This filling time is essential for ensuring adequate blood volume for the subsequent ventricular contraction (systole).

Question 63: Which electrolyte imbalance is most commonly associated with tall, peaked T waves on an ECG?

Hyponatremia
Hypokalemia
Hyperkalemia (Correct answer)
Hypercalcemia

Correct answer: Hyperkalemia

Hyperkalemia classically produces tall, narrow, peaked T waves as one of its earliest ECG manifestations.

Question 64: Which statement best describes the role of the EKG technician in patient confidentiality?

Technicians must protect patient information and only share results with authorized personnel per HIPAA guidelines (Correct answer)
Technicians may share EKG results with any healthcare worker who asks
Confidentiality applies only to written records, not verbal conversations
Technicians can share de-identified results on social media for educational purposes

Correct answer: Technicians must protect patient information and only share results with authorized personnel per HIPAA guidelines

Under HIPAA, EKG technicians must safeguard all patient health information and share results only with authorized members of the care team.

Question 65: What is the primary reason for cleaning EKG electrode sites with alcohol before application?

To sterilize the skin for surgical procedures
To make electrodes stick permanently
To reduce skin impedance and prevent infection (Correct answer)
To improve patient comfort

Correct answer: To reduce skin impedance and prevent infection

Alcohol prep reduces skin oils and microorganisms, lowering impedance for better signal quality while minimizing infection risk.

Question 66: What should an EKG technician do if a patient loses consciousness during the procedure?

Immediately call for help, activate emergency response, and stay with the patient (Correct answer)
Ask the patient's family to assist
Remove all electrodes and leave the patient to get help
Complete the EKG and then notify staff

Correct answer: Immediately call for help, activate emergency response, and stay with the patient

Patient safety is the absolute priority; the technician must immediately call for emergency assistance, remain with the patient, and initiate basic life support if trained and needed.

Question 67: Why is documentation important in Heart Rate & Rhythm Analysis?

It is irrelevant to patient care.
It is only used for billing purposes.
It provides a legal and medical record of diagnostic results. (Correct answer)
It is not necessary unless requested.

Correct answer: It provides a legal and medical record of diagnostic results.

Documentation of heart rate and rhythm analysis is vital because it creates a comprehensive legal and medical record of the patient's cardiac status at a specific time. This record is essential for tracking changes over time, ensuring continuity of care, and providing a reference for future treatment decisions. It also serves as evidence of proper diagnostic procedures and clinical decision-making, contributing to accountability.

Question 68: What is pacemaker syndrome?

Pacemaker-induced ventricular fibrillation
Oversensing causing inappropriate inhibition
Symptoms caused by loss of AV synchrony during ventricular-only pacing (Correct answer)
Infection around the pacemaker pocket site

Correct answer: Symptoms caused by loss of AV synchrony during ventricular-only pacing

Pacemaker syndrome occurs when VVI pacing causes loss of AV synchrony, leading to symptoms like hypotension, dizziness, fatigue, and pulsations in the neck due to atrial contraction against closed AV valves.

Question 69: Why is Electrode Placement & Lead Systems critical for early detection of heart conditions?

It plays a vital role in detecting heart conditions early, which improves treatment outcomes. (Correct answer)
It only helps with emergency diagnosis.
It has limited use in cardiac care.
It is only necessary when symptoms are severe.

Correct answer: It plays a vital role in detecting heart conditions early, which improves treatment outcomes.

Accurate electrode placement ensures that even subtle electrical abnormalities, indicative of early-stage heart conditions, are reliably captured by the EKG. Early detection allows for prompt intervention and management, which can significantly improve treatment outcomes, prevent disease progression, and reduce the risk of serious complications. Inaccurate placement can obscure these early signs, delaying crucial diagnosis and potentially worsening prognosis.

Question 70: The right coronary artery primarily supplies blood to which structure critical for the heart's electrical conduction?

Bundle of His
SA node and AV node (Correct answer)
Purkinje fibers
Left bundle branch

Correct answer: SA node and AV node

In most people the right coronary artery supplies blood to both the SA node and the AV node, making it critical for normal cardiac rhythm.

Question 71: Why is documentation important in Stress Testing & Holter Monitoring?

It provides a legal and medical record of diagnostic results. (Correct answer)
It is only used for billing purposes.
It is irrelevant to patient care.
It is not necessary unless requested.

Correct answer: It provides a legal and medical record of diagnostic results.

Documentation in Stress Testing and Holter Monitoring is critical as it creates a comprehensive legal and medical record of the diagnostic process and results. This detailed record includes patient responses, EKG findings, and any interventions, ensuring continuity of care and accountability. It serves as an essential reference for future medical decisions, legal purposes, and quality assurance.

Question 72: What does the term 'lead reversal' mean in the context of a 12-lead EKG?

The machine is printing leads in the wrong order
The sensitivity is inverted
The paper speed is reversed
Electrodes have been placed on incorrect body sites (Correct answer)

Correct answer: Electrodes have been placed on incorrect body sites

Lead reversal occurs when electrodes are attached to the wrong limbs or precordial positions, producing inaccurate or mirror-image tracings.

Question 73: What is the minimum recommended frequency for biomedical inspection of EKG equipment in a clinical setting?

Monthly
Every five years
Annually (Correct answer)
Only when visibly damaged

Correct answer: Annually

Most facility protocols and Joint Commission standards require annual biomedical safety inspections of patient-care electrical equipment.

Question 74: Which structure in the heart prevents backflow of blood into the right atrium?

The tricuspid valve. (Correct answer)
The mitral valve.
The aortic valve.
The pulmonary valve.

Correct answer: The tricuspid valve.

The tricuspid valve is located between the right atrium and the right ventricle of the heart. Its crucial role is to prevent the backflow of deoxygenated blood from the right ventricle into the right atrium during ventricular contraction (systole). This ensures that blood flows in the correct direction towards the lungs.

Question 75: What position should a patient be in when a resting 12-lead EKG is performed?

Sitting upright at 90 degrees
Supine (lying flat) with arms at the sides (Correct answer)
Left lateral decubitus
Semi-Fowler's position at 45 degrees

Correct answer: Supine (lying flat) with arms at the sides

The patient should be supine with arms relaxed at the sides to standardize electrode position, minimize muscle artifact, and ensure reproducible results.

Question 76: During a pharmacologic stress test using adenosine, which side effect should the EKG technician expect and prepare for?

Transient chest tightness and flushing (Correct answer)
Permanent AV block
Acute hypertensive crisis
Sustained ventricular tachycardia

Correct answer: Transient chest tightness and flushing

Adenosine commonly causes transient chest tightness, flushing, and brief AV conduction delays that resolve quickly due to its ultra-short half-life.

Question 77: What minimum duration is standard for a conventional Holter monitor recording to capture intermittent arrhythmias?

72 hours
24 hours (Correct answer)
48 hours
8 hours

Correct answer: 24 hours

The standard Holter monitoring duration is 24 hours, which captures a full cycle of daily activities including sleep to detect intermittent arrhythmias.

Question 78: What is the most likely cause of an intermittent or 'dropped' signal on one lead of a 12-lead EKG?

Machine calibration error
Loose or partially detached electrode on that lead (Correct answer)
60 Hz interference
Incorrect paper speed setting

Correct answer: Loose or partially detached electrode on that lead

An intermittent signal on one lead is most commonly caused by a loose electrode connection or a lead wire that is not fully snapped to the electrode.

Question 79: Which finding on an EKG is most consistent with hyperkalemia?

Prominent U waves
Prolonged QT interval
Tall, peaked T waves (Correct answer)
Short PR interval

Correct answer: Tall, peaked T waves

Hyperkalemia classically produces tall, narrow, peaked (tent-shaped) T waves, which are often the earliest EKG change. As potassium rises further, the PR interval prolongs, the QRS widens, and eventually a sine-wave pattern may develop.

Question 80: Which method is most accurate for calculating heart rate on an EKG strip with an irregular rhythm?

Divide 300 by the number of large boxes between R waves
Divide 1500 by the number of small boxes between R waves
Use the sequence method starting from an R wave on a dark line
Count R waves in a 6-second strip and multiply by 10 (Correct answer)

Correct answer: Count R waves in a 6-second strip and multiply by 10

The 6-second method is preferred for irregular rhythms because it averages the rate over multiple beats rather than relying on a single R-R interval.

Question 81: What is the correct action if the ground wire on a three-prong EKG power plug is missing or broken?

Remove the machine from service until repaired (Correct answer)
Wrap the cord with electrical tape
Use an adapter to convert to a two-prong plug
Continue using but document the issue

Correct answer: Remove the machine from service until repaired

A missing ground wire eliminates the safety path for stray current, making the equipment unsafe and requiring immediate removal from service.

Question 82: Which of the following best describes the purpose of EKG machine calibration?

To reset the patient data
To ensure the machine records a 1 mV signal as exactly 10 mm deflection (Correct answer)
To set the filter frequency
To adjust the paper speed

Correct answer: To ensure the machine records a 1 mV signal as exactly 10 mm deflection

Calibration ensures accuracy by confirming that a standard 1 mV test pulse produces the expected 10 mm deflection on the recording.

Question 83: What is the primary reason chest hair may need to be clipped before EKG electrode placement?

Hair reacts chemically with electrode gel
Chest hair prevents proper electrode-skin contact, increasing impedance and artifact (Correct answer)
Hair causes 60 Hz interference
It is a legal requirement for all male patients

Correct answer: Chest hair prevents proper electrode-skin contact, increasing impedance and artifact

Chest hair prevents full skin-to-electrode contact, increasing impedance and causing artifact; clipping (not shaving) the minimal area needed improves signal quality.

Question 84: Which type of personal protective equipment (PPE) is MOST essential when performing an EKG on a patient with contact precautions?

Face shield only
Gloves and gown (Correct answer)
N95 respirator only
Sterile surgical gloves

Correct answer: Gloves and gown

Contact precautions require gloves and gown to prevent transmission of organisms spread by direct or indirect contact.

Question 85: During an EKG, a technician notices the patient has a transdermal medication patch on the chest. What should the technician do?

Avoid placing electrodes directly on the patch and document its location (Correct answer)
Remove the patch to get a better tracing
Place the electrode on top of the patch for stability
Ignore it since patches do not affect EKG readings

Correct answer: Avoid placing electrodes directly on the patch and document its location

Placing electrodes on medication patches can cause burns or alter drug absorption; electrodes should be placed nearby and the patch location documented.

Question 86: During a Bruce Protocol stress test, what happens at each successive stage?

Only treadmill incline increases
Speed increases while incline decreases
Only treadmill speed increases
Both treadmill speed and incline increase (Correct answer)

Correct answer: Both treadmill speed and incline increase

The Bruce Protocol increases both speed and grade at each 3-minute stage to progressively intensify the cardiac workload.

Question 87: A technician is about to perform an EKG on a patient in airborne isolation. Which additional PPE beyond standard precautions is required?

Sterile gloves
N95 respirator (Correct answer)
Lead apron
Safety goggles only

Correct answer: N95 respirator

Airborne isolation requires an N95 or higher-level respirator to filter airborne pathogens such as tuberculosis or measles.

Question 88: What color is the right arm electrode lead wire in the standard US (AHA) color coding system?

Red
White (Correct answer)
Green
Black

Correct answer: White

In the AHA color coding system used in the US, the right arm electrode is white, while the left arm is black, right leg is green, and left leg is red.

Question 89: You are analyzing a rhythm strip and count 8 R waves within a 6-second interval. What is the calculated heart rate?

70 bpm
80 bpm (Correct answer)
90 bpm
60 bpm

Correct answer: 80 bpm

With the 6-second method, multiply the number of R-R intervals (which is one fewer than R waves: 8 − 1 = 7… however, the standard method counts complexes and multiplies by 10, giving 8 × 10 = 80 bpm.

Question 90: The following are ECG features associated with myocardial ischemia:

Prolongation of PR interval
Changes in the QRS complex and ST segment
Changes in the ST segment and T waves (Correct answer)
Widening of the QRS complex

Correct answer: Changes in the ST segment and T waves

Myocardial ischemia, a lack of oxygen to the heart muscle, primarily affects the repolarization phase of the cardiac cycle. On an ECG, this is typically reflected by changes in the ST segment, such as depression or elevation, and/or T wave abnormalities like inversion or flattening. These alterations indicate altered electrical activity in the oxygen-deprived heart muscle.

Question 91: Which of the following describes the function of a right leg (RL/N) electrode in a 12-lead EKG?

It serves as a ground electrode to reduce electrical interference (Correct answer)
It measures right ventricular activity
It balances the precordial leads
It records the inferior leads

Correct answer: It serves as a ground electrode to reduce electrical interference

The right leg electrode acts as a ground (neutral) electrode that helps cancel out electrical noise and interference, improving signal quality.

Question 92: A Holter monitor recording reveals frequent premature ventricular complexes (PVCs) occurring in a pattern of one PVC every third beat. What is this pattern called?

Ventricular tachycardia
Couplets
Trigeminy (Correct answer)
Bigeminy

Correct answer: Trigeminy

Trigeminy is the pattern where a PVC occurs every third beat, following two normal sinus beats in a repetitive cycle.

Question 93: In a 12-lead EKG, which leads view the lateral wall of the heart?

I, aVL, V5, V6 (Correct answer)
V1, V2
V3, V4
II, III, aVF

Correct answer: I, aVL, V5, V6

Leads I, aVL, V5, and V6 are positioned to view the lateral wall of the left ventricle.

Question 94: Which among the following ECG features sets atrial flutter apart from other atrial dysrhythmias:

P waves of varying sizes and amplitude
The Presence of Fibrillatory waves
The "Saw Tooth" or "Picket Fence" appearance of waveforms before QRS (Correct answer)
The Presence of Delta waves before QRS

Correct answer: The "Saw Tooth" or "Picket Fence" appearance of waveforms before QRS

Atrial flutter is characterized by a rapid, regular atrial rhythm, typically between 250-350 bpm, caused by a re-entrant circuit in the atria. On an ECG, this manifests as distinctive 'sawtooth' or 'picket fence' shaped flutter (F) waves, particularly visible in leads II, III, and aVF, replacing normal P waves. This unique morphology is a hallmark differentiating it from other atrial dysrhythmias.

Question 95: Which artifact pattern on an EKG is most commonly caused by AC (alternating current) electrical interference?

Intermittent signal dropout
60-cycle interference producing a thick, fuzzy baseline (Correct answer)
Muscle tremor artifact
Wandering baseline

Correct answer: 60-cycle interference producing a thick, fuzzy baseline

AC interference produces a characteristic 60-cycle per second artifact that appears as a thick, uniform fuzz on the baseline.

Question 96: A patient presents with an irregularly irregular rhythm with no discernible P waves on EKG. What is the most likely diagnosis?

Multifocal atrial tachycardia
Sinus arrhythmia
Atrial fibrillation (Correct answer)
Atrial flutter

Correct answer: Atrial fibrillation

Atrial fibrillation is characterized by an irregularly irregular rhythm with fibrillatory baseline and absence of organized P waves.

Question 97: What is the standard sensitivity setting on most EKG machines?

10 mm/mV (Correct answer)
5 mm/mV
20 mm/mV
1 mm/mV

Correct answer: 10 mm/mV

The standard sensitivity for EKG recording is 10 mm/mV, meaning a 1 mV signal produces a 10 mm deflection on the paper.

Question 98: How does Stress Testing & Holter Monitoring affect the diagnosis of heart conditions?

It has no role in diagnosing heart conditions.
It is used solely for monitoring heart rate.
It only applies to diagnosing respiratory issues.
It plays a significant role in identifying abnormal heart rhythms and other cardiac conditions. (Correct answer)

Correct answer: It plays a significant role in identifying abnormal heart rhythms and other cardiac conditions.

Stress Testing and Holter Monitoring play a significant role in diagnosing heart conditions by revealing abnormalities that are not apparent during a standard, resting EKG. These tests can identify exercise-induced ischemia, transient arrhythmias, or other cardiac issues that occur intermittently. This detailed information is invaluable for making precise diagnoses and understanding the full scope of a patient's cardiac health.

Question 99: A patient presents with chest pain and the EKG shows ST elevation in leads II, III, and aVF with reciprocal ST depression in leads I and aVL. Which type of myocardial infarction does this indicate?

Anterior MI
Posterior MI
Inferior MI (Correct answer)
Lateral MI

Correct answer: Inferior MI

Leads II, III, and aVF reflect the inferior surface of the heart, and ST elevation in these leads with reciprocal changes confirms an inferior MI.

Question 100: On a standard EKG running at 25 mm/s, one large box on the horizontal axis represents how much time?

0.40 seconds
0.04 seconds
0.10 seconds
0.20 seconds (Correct answer)

Correct answer: 0.20 seconds

At the standard paper speed of 25 mm/s, each large box (5 mm wide) equals 0.20 seconds. Each small box (1 mm wide) equals 0.04 seconds. This calibration is fundamental for measuring intervals such as PR, QRS, and QT correctly.

Certified EKG Technician (CET) Exam

The Certified EKG Technician (CET) exam, offered by the NHA, validates a healthcare professional's knowledge and skills in performing electrocardiograms.

100

Questions

120 min

Time Limit

70%

To Pass

Checking for saved progress...

Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds