Certified Electrocardiogram (EKG) Technician (CET) Exam — Questions and Answers

Question 1: According to standard ECG paper scale, how many small squares represent one large square on the horizontal (time) axis?

25 small squares
4 small squares
10 small squares
5 small squares (Correct answer)

Correct answer: 5 small squares

Each large square on ECG paper contains 5 small squares; at standard 25 mm/sec speed, each small square = 0.04 sec and each large square = 0.20 sec.

Question 2: What should be done before using an ECG machine?

Check battery, leads, and calibration (Correct answer)
Only wipe the screen
Turn on the machine for 5 seconds
Replace electrodes only

Correct answer: Check battery, leads, and calibration

Before using an ECG machine, a Certified Electrocardiogram Technician (CET) must perform a thorough pre-use check. This includes verifying the battery level to ensure uninterrupted operation, inspecting all leads for any signs of damage or wear, and confirming that the machine is properly calibrated. These steps are critical to guarantee accurate and reliable recordings of the patient's heart activity.

Question 3: How does pediatric ecg considerations contribute to professional excellence in CET certification?

It enhances competency, improves outcomes, and supports continuous professional growth (Correct answer)
It only matters during certification exams
It has no measurable impact on practice
It benefits organizations but not individual practitioners

Correct answer: It enhances competency, improves outcomes, and supports continuous professional growth

Pediatric ECG Considerations is integral to CET professional excellence, directly enhancing competency and driving measurable improvement in practice outcomes.

Question 4: A patient in the ICU has a heart rate of 38 bpm with hypotension and altered mental status. The monitor shows sinus bradycardia. First-line pharmacologic treatment is:

Lidocaine 1.5 mg/kg IV
Atropine 0.5 mg IV (Correct answer)
Amiodarone 300 mg IV
Adenosine 6 mg IV push

Correct answer: Atropine 0.5 mg IV

Atropine 0.5 mg IV (repeated up to 3 mg total) is the first-line drug for symptomatic sinus bradycardia by blocking vagal tone.

Question 5: ST elevation in leads II, III, and aVF with reciprocal changes in leads I and aVL indicates an infarction of the:

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

Correct answer: Inferior wall

Leads II, III, and aVF are the inferior leads; ST elevation in these leads with reciprocal changes laterally localizes the STEMI to the inferior wall.

Question 6: In a patient with known digoxin toxicity, which ECG finding is most characteristic?

Accelerated junctional rhythm only
Atrial flutter with 2:1 block
Bidirectional ventricular tachycardia (Correct answer)
Torsades de pointes

Correct answer: Bidirectional ventricular tachycardia

Bidirectional ventricular tachycardia, where the QRS axis alternates beat to beat, is highly specific for digitalis toxicity.

Question 7: When recording an ECG on a patient with a pacemaker, what specific concern should the technician note?

Pacemaker spikes will not appear on ECG
Artifact from the pacemaker may mimic bundle branch block morphology (Correct answer)
The machine's filter must be set to 0.5 Hz
Right-sided leads must always be added

Correct answer: Artifact from the pacemaker may mimic bundle branch block morphology

Pacemaker spikes followed by wide QRS complexes can resemble bundle branch blocks, so the technician must document the presence of a pacemaker on the ECG requisition.

Question 8: What is the correct placement for the V1 lead in a 12-lead ECG?

Fourth intercostal space, left of the sternum
Fourth intercostal space, right of the sternum (Correct answer)
Second intercostal space, right of the sternum
Midclavicular line, 5th intercostal space

Correct answer: Fourth intercostal space, right of the sternum

The correct placement for the V1 lead in a 12-lead ECG is the fourth intercostal space, just to the right of the sternum. This precise anatomical positioning is critical for accurately capturing the electrical activity from the right side of the heart. Proper lead placement ensures that the ECG tracing provides a standardized and comprehensive view of cardiac function, which is essential for diagnosis.

Question 9: What does a 'wandering baseline' on an ECG most commonly indicate?

Ventricular hypertrophy
Atrial fibrillation
Lead reversal
Patient movement or improper skin preparation (Correct answer)

Correct answer: Patient movement or improper skin preparation

A wandering baseline is typically caused by poor electrode contact, patient breathing, movement, or inadequate skin preparation preventing stable electrical conduction.

Question 10: What action should be taken before applying chest electrodes on a patient with excessive chest hair?

Use longer electrode wires to route around hair-covered areas
Never alter a patient's appearance regardless of the effect on signal quality
Clip or shave the area only after obtaining the patient's explicit consent (Correct answer)
Apply electrodes directly on top of hair with extra gel

Correct answer: Clip or shave the area only after obtaining the patient's explicit consent

Hair prevents adequate electrode-skin contact, and shaving or clipping with consent is often necessary for an accurate tracing.

Question 11: Which safety precaution is essential when performing an ECG on a patient with an implanted pacemaker?

Document the presence of the pacemaker and note it on the ECG requisition (Correct answer)
Disable the pacemaker temporarily before recording
Skip precordial leads to avoid interference with the device
Use twice the standard voltage gain setting on the machine

Correct answer: Document the presence of the pacemaker and note it on the ECG requisition

Documenting the device ensures the interpreting physician accounts for pacemaker spikes and altered waveform morphology.

Question 12: How should a technician respond if a patient becomes anxious or distressed during an ECG?

Continue without interruption to finish the recording as fast as possible
Administer a sedative and then resume when the patient is calm
Pause the procedure, reassure the patient, and address their concerns (Correct answer)
Increase recording speed to complete the test more quickly

Correct answer: Pause the procedure, reassure the patient, and address their concerns

Patient comfort and safety take priority, and anxiety also causes muscle artifact that degrades tracing quality.

Question 13: What electrode placement modification is used for small infants when standard chest electrode spacing is too large?

Skip precordial leads V3 and V5
Use limb leads only and omit chest leads
Place all precordial leads in the left hemithorax only
Use pediatric (smaller) electrode pads and reposition to fit the chest (Correct answer)

Correct answer: Use pediatric (smaller) electrode pads and reposition to fit the chest

Pediatric-sized electrode pads are used on small infants and repositioned proportionally across the smaller chest wall to maintain anatomically correct lead placement.

Question 14: What is the relationship between ecg artifact troubleshooting and overall Certified Electrocardiogram Technician professional competency?

It is an essential component that strengthens the overall competency framework (Correct answer)
It only applies to senior practitioners
It is a minor supplementary skill
They are completely unrelated areas

Correct answer: It is an essential component that strengthens the overall competency framework

ECG Artifact Troubleshooting is an essential component of the CET competency framework, strengthening overall professional capability and credibility.

Question 15: A 12-lead ECG shows ST elevation in leads V1–V3 that increases with right-sided precordial leads (V3R–V4R). This pattern suggests:

Left ventricular anterior STEMI
Right ventricular infarction (Correct answer)
Anterior pericarditis
Left bundle branch block with ischemia

Correct answer: Right ventricular infarction

ST elevation that is prominent in right-sided leads (V3R, V4R) indicates right ventricular myocardial infarction, often accompanying inferior STEMI.

Question 16: Which PPE consideration applies to ECG technicians under standard precautions?

Wear an N95 respirator for all ECG procedures regardless of patient status
Wear gloves when contact with body fluids, open wounds, or non-intact skin is possible (Correct answer)
PPE is not required because ECG is a completely non-invasive procedure
Wear a full surgical gown and face shield for every ECG procedure

Correct answer: Wear gloves when contact with body fluids, open wounds, or non-intact skin is possible

Standard precautions require gloves when there is potential contact with blood, body fluids, or non-intact skin.

Question 17: When recording a pediatric ECG, the standard paper speed and gain settings are:

25 mm/s and 20 mm/mV
25 mm/s and 10 mm/mV (Correct answer)
12.5 mm/s and 10 mm/mV
50 mm/s and 20 mm/mV

Correct answer: 25 mm/s and 10 mm/mV

Standard ECG settings are 25 mm/s paper speed and 10 mm/mV gain (1 mV = 10 mm) for both pediatric and adult recordings; these settings are used unless otherwise specified.

Question 18: Which pediatric ECG finding should prompt immediate evaluation for hypertrophic cardiomyopathy (HCM)?

First-degree AV block with PR interval of 210 ms
Right axis deviation in a 3-month-old
Sinus bradycardia with a rate of 55 bpm
Deeply inverted T waves and voltage criteria for left ventricular hypertrophy (Correct answer)

Correct answer: Deeply inverted T waves and voltage criteria for left ventricular hypertrophy

HCM produces LVH voltage criteria combined with deep, widespread T-wave inversions—often the electrical hallmark of this condition and a leading cause of sudden cardiac death in young athletes.

Question 19: During emergency monitoring, continuous ST-segment trending is most useful for detecting:

QT prolongation from antiarrhythmics
Bundle branch block development
Electrolyte-induced arrhythmias
Silent or ongoing myocardial ischemia (Correct answer)

Correct answer: Silent or ongoing myocardial ischemia

Continuous ST trending allows real-time detection of ischemic episodes, including silent ischemia that produces no symptoms but carries prognostic significance.

Question 20: Why must patients avoid caffeine for at least 12–24 hours before a pharmacologic stress test using adenosine or regadenoson?

Caffeine increases the risk of adenosine-induced bronchospasm
Caffeine causes artifact on the ECG baseline
Caffeine competitively blocks adenosine receptors, blunting vasodilation (Correct answer)
Caffeine raises resting heart rate, invalidating MPHR calculation

Correct answer: Caffeine competitively blocks adenosine receptors, blunting vasodilation

Caffeine and theophylline are adenosine receptor antagonists; their presence blocks the coronary vasodilatory effect of adenosine, producing a false-negative study.

Question 21: What is the normal serum potassium reference range?

1.5-2.5 mEq/L
3.5-5.0 mEq/L (Correct answer)
2.0-3.5 mEq/L
5.5-7.0 mEq/L

Correct answer: 3.5-5.0 mEq/L

Normal serum potassium is 3.5-5.0 mEq/L; values below 3.5 (hypokalemia) and above 5.0 (hyperkalemia) both produce progressive ECG changes.

Question 22: Which characteristic of 60 Hz AC interference helps differentiate it from atrial fibrillation on a rhythm strip?

AC interference disappears only when the low-pass filter is set below 40 Hz
Atrial fibrillation always has a heart rate above 150 bpm
Atrial fibrillation produces a flat baseline between QRS complexes
AC interference has a perfectly regular frequency of 60 cycles per second (Correct answer)

Correct answer: AC interference has a perfectly regular frequency of 60 cycles per second

AC interference produces a precisely regular 60-per-second oscillation, while atrial fibrillation produces irregularly irregular, variable-amplitude fibrillatory waves.

Question 23: The sensitivity (gain) setting of 10 mm/mV means:

10 mV produces a 1 mm deflection
1 mV of cardiac signal produces a 10 mm deflection on the ECG paper (Correct answer)
The filter is set to 10 Hz
The paper speed is set to 10 mm/sec

Correct answer: 1 mV of cardiac signal produces a 10 mm deflection on the ECG paper

Standard sensitivity is 10 mm/mV, so a 1 mV calibration pulse deflects the stylus exactly 10 mm (two large squares).

Question 24: When troubleshooting AC interference on an ECG, which action should be performed LAST?

Reapply electrodes with fresh gel
Ensure all lead wires are untangled
Engage the ECG machine's built-in 60 Hz notch filter as a permanent solution (Correct answer)
Move the patient away from electrical equipment

Correct answer: Engage the ECG machine's built-in 60 Hz notch filter as a permanent solution

The notch filter should be a last resort because it can distort ST segments and T-wave morphology, potentially masking clinically relevant changes.

Question 25: A patient with a pacemaker shows occasional QRS complexes not preceded by a pacemaker spike, yet the pacemaker appears to function normally otherwise. This is most consistent with:

Failure to capture
Pacemaker-mediated tachycardia
Normal demand pacemaker function with intrinsic beats (Correct answer)
Failure to sense (undersensing)

Correct answer: Normal demand pacemaker function with intrinsic beats

A demand pacemaker senses intrinsic beats and inhibits its own output; native QRS complexes without pacemaker spikes reflect normal sensing and inhibition.

Question 26: Which lead is considered the 'ground' or reference electrode in a standard 12-lead ECG setup?

Right arm (RA)
Left arm (LA)
Right leg (RL) (Correct answer)
Left leg (LL)

Correct answer: Right leg (RL)

The right leg (RL) electrode serves as the electrical ground or reference and does not contribute to any of the 12 leads.

Question 27: What term describes the period during which the ventricles are filling with blood?

Ejection phase
Isovolumetric contraction
Systole
Diastole (Correct answer)

Correct answer: Diastole

Diastole is the relaxation phase of the cardiac cycle when the ventricles fill with blood from the atria.

Question 28: A newborn's ECG 48 hours after birth shows a QRS axis of +180 degrees (extreme right axis). This is MOST consistent with:

Normal finding in neonates
Left ventricular hypertrophy
Significant right ventricular hypertrophy or congenital heart defect (Correct answer)
Hyperkalemia

Correct answer: Significant right ventricular hypertrophy or congenital heart defect

While moderate right axis deviation is normal in neonates, extreme right axis deviation (+180°) is abnormal and warrants evaluation for right ventricular hypertrophy or structural heart disease.

Question 29: A patient's ECG shows a regular narrow-complex tachycardia at 170 bpm. After carotid sinus massage, the rate abruptly drops to 75 bpm. This response is most consistent with:

Atrial flutter with 2:1 block
Sinus tachycardia
Ventricular tachycardia
AV nodal reentrant tachycardia (AVNRT) (Correct answer)

Correct answer: AV nodal reentrant tachycardia (AVNRT)

AVNRT depends on the AV node for its reentrant circuit; vagal maneuvers that slow AV conduction will abruptly terminate the tachycardia rather than gradually slow it.

Question 30: The left anterior descending (LAD) artery primarily supplies which area of the heart?

Anterior wall of the left ventricle and anterior septum (Correct answer)
Posterior wall of the left ventricle
Right ventricle free wall
SA and AV nodes

Correct answer: Anterior wall of the left ventricle and anterior septum

The LAD artery supplies the anterior wall of the left ventricle, the anterior two-thirds of the interventricular septum, and the apex.

Question 31: Which coronary artery primarily supplies the left ventricle's lateral wall?

Left anterior descending artery
Right coronary artery
Posterior descending artery
Left circumflex artery (Correct answer)

Correct answer: Left circumflex artery

The left circumflex artery branches from the left main coronary artery and supplies the lateral wall of the left ventricle.

Question 32: An ECG showing a P-wave axis of +150° (inverted in leads I and aVF, upright in aVR) with a short PR interval most likely indicates:

Junctional rhythm with antegrade conduction
Sinus rhythm with left axis deviation
Ectopic atrial rhythm originating from the low right atrium or coronary sinus (Correct answer)
Atrial flutter with inverted flutter waves

Correct answer: Ectopic atrial rhythm originating from the low right atrium or coronary sinus

A P-wave axis of approximately +150° suggests atrial activation spreading superiorly and rightward, consistent with a low atrial or coronary sinus pacemaker rather than the sinus node.

Question 33: What is the standard duration of a resting 12-lead ECG recording in the United States?

30 seconds of continuous recording
1 minute with each lead recorded separately
Approximately 10 seconds capturing all 12 leads simultaneously (Correct answer)
5 minutes to document multiple complete cardiac cycles

Correct answer: Approximately 10 seconds capturing all 12 leads simultaneously

Standard 12-lead ECGs capture approximately 10 seconds of rhythm to document one or more complete cardiac cycles per lead.

Question 34: During Holter analysis, a technician notices the patient's heart rate drops to 28 bpm for 6 seconds during sleep. This finding is most consistent with:

Vagally mediated sinus pause, common during sleep (Correct answer)
Junctional escape rhythm
Complete heart block
Sinus bradycardia requiring immediate intervention

Correct answer: Vagally mediated sinus pause, common during sleep

Brief nocturnal sinus pauses up to 2–3 seconds are a normal vagal phenomenon in athletes and during sleep; isolated pauses without symptoms are usually benign.

Question 35: Which of the following is the proper instruction to give a patient immediately before recording the ECG?

'Cross your arms over your chest to reduce lead movement.'
'Lie still, breathe normally, and do not talk or move.' (Correct answer)
'Take a deep breath and hold it during the recording.'
'Clench your fists to help stabilize the electrodes.'

Correct answer: 'Lie still, breathe normally, and do not talk or move.'

Patients should breathe normally and remain completely still; talking, movement, or breath-holding all introduce artifact that degrades tracing quality.

Question 36: What is the primary purpose of calibrating an ECG machine?

To ensure accurate output of waveforms (Correct answer)
To clean the machine's internal components.
To update its software.
To check for electrical interference.

Correct answer: To ensure accurate output of waveforms

Calibrating an ECG machine is a crucial maintenance step that involves adjusting its settings to a known standard. This process ensures that the machine accurately measures and displays the heart's electrical activity, producing waveforms that are correctly scaled and precisely interpretable. Proper calibration is essential for reliable diagnostic readings.

Question 37: An infant presents with a ventricular rate of 250 bpm, narrow QRS complexes, and no discernible P waves. The MOST likely rhythm is:

Supraventricular tachycardia (SVT) (Correct answer)
Sinus tachycardia
Complete heart block
Ventricular tachycardia

Correct answer: Supraventricular tachycardia (SVT)

SVT in infants typically presents with rates of 220–300 bpm, narrow QRS, and absent or retrograde P waves buried in the T wave, distinguishing it from sinus tachycardia.

Question 38: How does 12-lead ecg interpretation contribute to professional excellence in CET certification?

It only matters during certification exams
It benefits organizations but not individual practitioners
It enhances competency, improves outcomes, and supports continuous professional growth (Correct answer)
It has no measurable impact on practice

Correct answer: It enhances competency, improves outcomes, and supports continuous professional growth

12-Lead ECG Interpretation is integral to CET professional excellence, directly enhancing competency and driving measurable improvement in practice outcomes.

Question 39: What action should be taken if a patient experiences dizziness during an ECG?

Ignore and complete the ECG
Assess the patient and notify the provider (Correct answer)
Continue while checking the wires
Stop the test and discharge the patient

Correct answer: Assess the patient and notify the provider

Patient safety is paramount during any medical procedure. If a patient experiences dizziness during an ECG, it could indicate an adverse reaction or an underlying medical issue. The technician must immediately assess the patient's condition, ensure their safety, and promptly notify the healthcare provider. Continuing the test without assessment could endanger the patient and delay necessary medical intervention.

Question 40: Which ECG finding in a child with chest pain and a history of Kawasaki disease should raise concern for myocardial ischemia?

ST-segment elevation and Q waves in the inferolateral leads (Correct answer)
Sinus arrhythmia
Peaked P waves in lead II
Right bundle branch block without ST changes

Correct answer: ST-segment elevation and Q waves in the inferolateral leads

Kawasaki disease can cause coronary artery aneurysms leading to thrombosis and myocardial infarction; ST elevation and pathological Q waves indicate ischemic injury in this clinical context.

Question 41: What should a technician do if a patient's skin is excessively oily or diaphoretic before applying ECG electrodes?

Proceed without any special preparation to save time
Cleanse the skin with an alcohol wipe and allow it to dry completely before placing electrodes (Correct answer)
Increase the gain setting on the ECG machine to compensate
Apply extra adhesive tape over the electrodes to secure them

Correct answer: Cleanse the skin with an alcohol wipe and allow it to dry completely before placing electrodes

Alcohol removes oils and sweat that would otherwise increase skin impedance and degrade electrode contact quality.

Question 42: Which statement best describes informed consent requirements for a routine ECG?

Only verbal consent from a family member is acceptable
Consent is not needed because ECG poses zero risk
A signed surgical consent form is required before every ECG
The patient should be informed of the procedure and its non-invasive nature (Correct answer)

Correct answer: The patient should be informed of the procedure and its non-invasive nature

Patients should understand what the procedure involves even though ECG is non-invasive and carries minimal risk.

Question 43: When performing an ECG on a crying infant, the technician should FIRST:

Apply additional electrodes to reduce noise
Increase the paper speed to 50 mm/s
Proceed with the recording and note the artifact
Attempt to calm the infant before recording (Correct answer)

Correct answer: Attempt to calm the infant before recording

Muscle artifact from crying significantly degrades ECG quality, so calming the infant first—using a pacifier, feeding, or parental soothing—produces a more accurate tracing.

Question 44: A patient on chronic amiodarone therapy develops thyroid dysfunction. Which ECG finding might accompany amiodarone-induced hypothyroidism?

Peaked T waves with narrow QRS
Short PR interval with delta waves
ST elevation in precordial leads
Prolonged QT with bradycardia (Correct answer)

Correct answer: Prolonged QT with bradycardia

Hypothyroidism slows the heart rate and prolongs the QT interval; amiodarone-induced hypothyroidism can exaggerate these effects.

Question 45: A technician notices the ECG machine displays 'LEAD FAIL' for lead II. Which electrode connection should be checked first?

Right arm (RA) and left arm (LA) electrodes
Right arm (RA) and left leg (LL) electrodes (Correct answer)
Right leg (RL) and left leg (LL) electrodes
Left arm (LA) and left leg (LL) electrodes

Correct answer: Right arm (RA) and left leg (LL) electrodes

Lead II is derived from the potential difference between the right arm (RA, negative) and left leg (LL, positive), so those connections should be checked.

Question 46: A child's ECG shows delta waves, a short PR interval, and wide QRS complexes. This pattern indicates:

Wolff-Parkinson-White (WPW) syndrome (Correct answer)
Left bundle branch block
Brugada syndrome
Complete heart block

Correct answer: Wolff-Parkinson-White (WPW) syndrome

WPW syndrome is characterized by ventricular pre-excitation via an accessory pathway, producing a delta wave, shortened PR interval, and widened QRS on the ECG.

Question 47: Why is documenting the clinical indication for an ECG (reason for the test) important?

Indications are never documented on ECG tracings in standard practice
Only for billing — the indication has no impact on clinical interpretation
It helps correlate ECG findings with the patient's presenting symptoms for more accurate interpretation (Correct answer)
The indication is recorded only by the ordering physician, not the performing technician

Correct answer: It helps correlate ECG findings with the patient's presenting symptoms for more accurate interpretation

Clinical context such as chest pain, syncope, or pre-operative screening directly influences how ECG findings are interpreted.

Question 48: When a patient has a permanent pacemaker, a pacemaker spike artifact appears on the ECG. Which action would be INCORRECT when troubleshooting apparent artifact around these spikes?

Document that the patient has a pacemaker on the requisition
Disable pacemaker detection mode on the ECG machine to clean up the tracing (Correct answer)
Verify proper lead placement to ensure spikes are not lead-related
Check for adequate electrode contact to reduce lead noise near the spikes

Correct answer: Disable pacemaker detection mode on the ECG machine to clean up the tracing

Pacemaker detection mode must remain enabled; disabling it suppresses true pacemaker spikes, which are clinically essential for assessing pacemaker function.

Question 49: What color is typically used for the left arm electrode in a standard ECG?

Black (Correct answer)
Red
White
Green

Correct answer: Black

In the standard American Heart Association (AHA) color code for ECG limb leads, the left arm electrode is typically black. Standardized color-coding systems are essential for ensuring consistent and correct electrode placement across different healthcare settings. This helps prevent lead misplacement errors, which could lead to inaccurate ECG interpretations and potentially incorrect diagnoses.

Question 50: What is the relationship between holter monitoring & ambulatory ecg and overall Certified Electrocardiogram Technician professional competency?

They are completely unrelated areas
It only applies to senior practitioners
It is an essential component that strengthens the overall competency framework (Correct answer)
It is a minor supplementary skill

Correct answer: It is an essential component that strengthens the overall competency framework

Holter Monitoring & Ambulatory ECG is an essential component of the CET competency framework, strengthening overall professional capability and credibility.

Question 51: During telemetry monitoring, a patient shows 'sawtooth' flutter waves at approximately 300 bpm with a 4:1 AV conduction ratio. The ventricular rate would be:

75 bpm (Correct answer)
150 bpm
100 bpm
300 bpm

Correct answer: 75 bpm

With 4:1 conduction, only 1 of every 4 atrial impulses conducts: 300 ÷ 4 = 75 bpm ventricular rate.

Question 52: Before applying ECG electrodes, what skin preparation step most directly improves signal quality?

Clean and dry the skin, removing excess hair if necessary (Correct answer)
Apply ice to cool the skin before electrode placement
Apply a thick layer of lotion to the skin
Leave the skin untouched to avoid discomfort

Correct answer: Clean and dry the skin, removing excess hair if necessary

Proper skin preparation reduces impedance and improves electrode contact, resulting in a cleaner tracing.

Question 53: How does ecg artifact troubleshooting contribute to professional excellence in CET certification?

It has no measurable impact on practice
It benefits organizations but not individual practitioners
It only matters during certification exams
It enhances competency, improves outcomes, and supports continuous professional growth (Correct answer)

Correct answer: It enhances competency, improves outcomes, and supports continuous professional growth

ECG Artifact Troubleshooting is integral to CET professional excellence, directly enhancing competency and driving measurable improvement in practice outcomes.

Question 54: How should CET professionals measure success in stress testing procedures?

Through subjective self-assessment only
Using defined metrics, benchmarks, and regular evaluation against established goals (Correct answer)
Success measurement is not applicable
By comparing only to minimum requirements

Correct answer: Using defined metrics, benchmarks, and regular evaluation against established goals

Success in stress testing procedures is measured through defined metrics and benchmarks, with regular evaluation against established professional goals.

Question 55: In a 10-year-old, the normal PR interval range is approximately:

60–80 ms
100–200 ms (Correct answer)
200–240 ms
240–280 ms

Correct answer: 100–200 ms

The normal PR interval in children aged 10 is approximately 100–200 ms (0.10–0.20 s), similar to adults but with the lower bound reflecting faster conduction.

Question 56: Which lead placement error would cause the P wave to appear inverted in lead I?

RA and LA electrodes reversed (Correct answer)
V1 placed too high on the chest
RL and LL electrodes reversed
LA and LL electrodes reversed

Correct answer: RA and LA electrodes reversed

Reversing the right arm (RA) and left arm (LA) electrodes inverts the polarity of lead I, causing the P wave and QRS to appear negative in that lead.

Question 57: A patient has excessive chest hair that prevents adequate electrode adhesion. What is the correct course of action?

Apply more conductive gel over the hair
Skip those leads and note it on the report
Shave or clip the hair before placing the electrode (Correct answer)
Place the electrode on an adjacent hairless area

Correct answer: Shave or clip the hair before placing the electrode

Shaving or clipping chest hair at the electrode site is the accepted procedure to ensure skin contact and artifact-free recording.

Question 58: What does the '1 mV standardization mark' at the beginning of an ECG tracing verify?

That the low-pass filter is active
That the machine's sensitivity is properly calibrated at 10 mm/mV (Correct answer)
That electrode impedance is within range
That the paper speed is correct

Correct answer: That the machine's sensitivity is properly calibrated at 10 mm/mV

The 1 mV standard pulse should produce a 10 mm (two large squares) deflection, confirming the machine is calibrated at standard sensitivity.

Question 59: When scanning Holter recordings using software, the technician's primary role is to:

Manually measure each QRS interval without software assistance
Accept all computer-generated beat classifications without review
Verify, edit, and confirm computer auto-analysis for accuracy (Correct answer)
Generate the final report without physician review

Correct answer: Verify, edit, and confirm computer auto-analysis for accuracy

Holter technicians must critically review and correct automated beat classifications because software algorithms are imperfect and can misclassify artifact or arrhythmias.

Question 60: In severe hyperkalemia, the ECG 'sine wave' pattern results from:

Accelerated junctional rhythm
Atrial flutter with variable block
Complete right bundle branch block
QRS widening merging with the T wave (Correct answer)

Correct answer: QRS widening merging with the T wave

As hyperkalemia worsens, progressive QRS widening causes the complex to merge with the T wave, creating a sinusoidal pattern that precedes cardiac arrest.

Question 61: What challenge is most commonly encountered in ecg artifact troubleshooting within Certified Electrocardiogram Technician practice?

Resistance to change and difficulty maintaining consistency across stakeholders (Correct answer)
Excessive regulatory support
Lack of available training materials
Unlimited budget allocation

Correct answer: Resistance to change and difficulty maintaining consistency across stakeholders

The most common challenge in ecg artifact troubleshooting is overcoming resistance to change while maintaining consistent implementation across diverse stakeholders.

Question 62: V5 is placed at the:

Fifth ICS, left midclavicular line
Fourth ICS, left anterior axillary line
Fifth ICS, left midaxillary line
Fifth ICS, left anterior axillary line (Correct answer)

Correct answer: Fifth ICS, left anterior axillary line

V5 is positioned at the left anterior axillary line at the same horizontal level as V4, progressing laterally from V4.

Question 63: An ECG technician is performing a routine equipment check and finds the stylus is producing a faint, uneven trace. What is the most likely cause?

The gain is set too low
The patient cable is damaged
The stylus pressure or temperature is incorrect (Correct answer)
The paper speed is set too fast

Correct answer: The stylus pressure or temperature is incorrect

A faint or uneven trace from the stylus typically indicates incorrect stylus pressure or temperature setting on a thermal writing system.

Question 64: Lead V4R is frequently added to pediatric ECGs. Its PRIMARY purpose is to:

Evaluate right ventricular activity, especially in congenital heart disease (Correct answer)
Measure the QT interval more accurately
Detect posterior wall myocardial infarction
Improve detection of left ventricular hypertrophy

Correct answer: Evaluate right ventricular activity, especially in congenital heart disease

V4R (right-sided precordial lead) is placed at the mirror image of V4 on the right chest wall to evaluate right ventricular forces, which is particularly important in congenital heart disease assessment.

Question 65: What is the correct action if a patient reports an adhesive allergy during ECG preparation?

Proceed as normal since ECG electrodes contain no latex or adhesive
Substitute hypoallergenic or non-adhesive electrodes to complete the test (Correct answer)
Apply standard electrodes directly over the patient's clothing
Cancel the procedure entirely and reschedule

Correct answer: Substitute hypoallergenic or non-adhesive electrodes to complete the test

Hypoallergenic electrodes can be substituted to safely complete the ECG for patients with adhesive allergies.

Question 66: Which ECG finding is most specific for hypocalcemia compared to other QT-prolonging conditions?

Widened QRS complex
Peaked T waves
Prominent U waves
Prolonged ST segment with a relatively normal T wave (Correct answer)

Correct answer: Prolonged ST segment with a relatively normal T wave

Hypocalcemia uniquely prolongs the isoelectric ST segment rather than the T wave itself, so the QT appears long but T wave morphology remains relatively normal.

Question 67: Which of the following arrhythmias is characterized by 'sawtooth' flutter waves at approximately 300 bpm on the ECG?

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

Correct answer: Atrial flutter

Atrial flutter produces characteristic sawtooth flutter waves (F waves) at ~300 bpm, best seen in leads II, III, aVF, and V1.

Question 68: What is a common sign of myocardial infarction on an ECG?

T wave inversion only
Shortened PR interval
ST-segment elevation (Correct answer)
Prolonged QT interval

Correct answer: ST-segment elevation

ST-segment elevation on an ECG is a hallmark sign of acute myocardial infarction (heart attack), specifically an ST-elevation myocardial infarction (STEMI). It indicates significant myocardial injury where a portion of the heart muscle is deprived of blood flow, causing characteristic electrical changes. Rapid identification of ST elevation is critical for immediate intervention and reperfusion therapy to minimize heart damage.

Question 69: How should CET professionals measure success in arrhythmia recognition & classification?

Through subjective self-assessment only
By comparing only to minimum requirements
Using defined metrics, benchmarks, and regular evaluation against established goals (Correct answer)
Success measurement is not applicable

Correct answer: Using defined metrics, benchmarks, and regular evaluation against established goals

Success in arrhythmia recognition & classification is measured through defined metrics and benchmarks, with regular evaluation against established professional goals.

Question 70: What is the most appropriate response when a patient reports active chest pain immediately before an ECG?

Administer nitroglycerin and wait 10 minutes before beginning
Ask the patient to wait until the pain subsides before proceeding
Defer the ECG and notify nursing staff or the physician immediately without recording
Perform the ECG promptly during active symptoms to capture potential ischemic changes (Correct answer)

Correct answer: Perform the ECG promptly during active symptoms to capture potential ischemic changes

Performing the ECG promptly during active chest pain can capture real-time ischemic changes that are critical for diagnosis.

Question 71: The augmented limb leads (aVR, aVL, aVF) differ from standard limb leads in that they:

Use an exploring electrode and a computed reference (central terminal) (Correct answer)
Require additional electrodes not used in standard leads
Are bipolar leads measuring voltage between two limbs
Record from the chest wall rather than the limbs

Correct answer: Use an exploring electrode and a computed reference (central terminal)

Augmented leads are unipolar; each uses one limb electrode as the positive (exploring) pole and a computed average of the other two limb electrodes as the negative reference (Wilson's central terminal variant).

Question 72: Which lead is placed at the midaxillary line, level with V4?

V4
V5
V6 (Correct answer)
V2

Correct answer: V6

The V6 lead is a precordial (chest) lead positioned at the midaxillary line, horizontally level with V4 and V5. This specific placement allows V6 to record the electrical activity primarily from the lateral wall of the left ventricle. Correct and consistent placement of all precordial leads, including V6, is fundamental for obtaining an accurate and diagnostically valuable 12-lead ECG.

Question 73: What is the standard patient position for a resting 12-lead ECG?

Left lateral decubent with knees bent
Supine (lying flat) with arms at the sides (Correct answer)
Standing with arms relaxed at the sides
Sitting upright at 90 degrees

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

The supine position standardizes the ECG recording and eliminates positional variation in waveform morphology.

Question 74: A 7-year-old's ECG shows a QRS axis of +110 degrees. How should this be interpreted?

Right axis deviation, potentially abnormal at this age (Correct answer)
Extreme axis deviation
Normal finding for this age
Left axis deviation

Correct answer: Right axis deviation, potentially abnormal at this age

By age 7, the QRS axis should fall between 0° and +90°; an axis of +110° represents right axis deviation and may indicate right ventricular hypertrophy or other pathology.

Question 75: A patient on furosemide develops ST depression, T wave flattening, and prominent U waves. The most likely electrolyte cause is:

Hypokalemia (Correct answer)
Hypermagnesemia
Hyponatremia
Hypercalcemia

Correct answer: Hypokalemia

Loop diuretics like furosemide cause renal potassium wasting; hypokalemia classically produces ST depression, T wave flattening, and prominent U waves.

Question 76: When cleaning reusable ECG electrodes, which agent should be avoided because it can degrade the metal contact surface?

Isopropyl alcohol
Hydrogen peroxide
Sodium hypochlorite (bleach) (Correct answer)
Warm soapy water

Correct answer: Sodium hypochlorite (bleach)

Sodium hypochlorite (bleach) can corrode and pit metal electrode surfaces, degrading conductivity over time.

Question 77: When checking for the source of artifact on a 12-lead ECG, a technician should systematically evaluate leads in groups. Which grouping is correct for identifying a faulty LIMB lead?

Artifact in all precordial leads suggests a left leg electrode problem
Artifact in leads I, II, and aVR but not III or aVL suggests a right arm electrode problem (Correct answer)
Artifact in V1–V3 suggests a right arm electrode problem
Artifact isolated to aVF only suggests a precordial electrode problem

Correct answer: Artifact in leads I, II, and aVR but not III or aVL suggests a right arm electrode problem

The right arm electrode contributes to leads I, II, and aVR; if those three leads share artifact while III and aVL (which both exclude RA) are clean, the RA electrode is the culprit.

Question 78: What type of patient protection is built into ECG machines to prevent electrical hazards?

Standard household circuit breaker protection
Rubber gloves worn by the technician during recording
An isolated patient circuit that prevents dangerous current flow through the patient (Correct answer)
Ground isolation using a standard copper grounding wire

Correct answer: An isolated patient circuit that prevents dangerous current flow through the patient

Isolated patient circuits in medical-grade ECG machines prevent dangerous electrical current from passing through the patient.

Question 79: How many seconds of rhythm strip is the minimum typically required on a standard 12-lead ECG printout?

5 seconds
60 seconds
10 seconds (Correct answer)
30 seconds

Correct answer: 10 seconds

A minimum 10-second recording is standard, long enough to capture at least one full cardiac cycle in most heart rates and assess rhythm.

Question 80: The Brugada pattern on an ECG is characterized by:

Coved-type ST elevation in V1–V2 with RBBB morphology (Correct answer)
ST elevation in V4–V6 with LBBB
Delta waves and shortened PR in V1–V2
ST depression in V1–V3 with right bundle branch block

Correct answer: Coved-type ST elevation in V1–V2 with RBBB morphology

The classic Brugada pattern shows a coved-type (downsloping) ST elevation ≥2 mm in V1–V2 with an incomplete or complete RBBB appearance.

Question 81: The standard paper speed for a resting 12-lead ECG in the United States is:

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

Correct answer: 25 mm/sec

25 mm/sec is the standard paper speed in the US, making each small square represent 0.04 seconds and each large square 0.20 seconds.

Question 82: What is a key principle of arrhythmia recognition & classification in Certified Electrocardiogram Technician practice?

Applying structured methodologies based on evidence and best practices (Correct answer)
Avoiding all standardized approaches
Minimizing documentation requirements
Relying solely on personal experience

Correct answer: Applying structured methodologies based on evidence and best practices

Arrhythmia Recognition & Classification in Certified Electrocardiogram Technician practice requires applying structured, evidence-based methodologies while adapting to specific professional contexts.

Question 83: In a 12-lead ECG, right axis deviation with an S1Q3T3 pattern suggests:

Pericarditis
Acute inferior STEMI
Pulmonary embolism (Correct answer)
Left ventricular hypertrophy

Correct answer: Pulmonary embolism

The S1Q3T3 pattern (S wave in I, Q wave and inverted T wave in III) with right axis deviation is a classic but nonspecific ECG finding in pulmonary embolism.

Question 84: Hypercalcemia typically produces which ECG finding?

Peaked T waves
Prolonged QT interval
Prominent U waves
Shortened QT interval (Correct answer)

Correct answer: Shortened QT interval

Hypercalcemia shortens the ST segment and QT interval because elevated calcium accelerates ventricular repolarization.

Question 85: The Brugada pattern on an ECG is characterized by which of the following?

Horizontal ST depression in V4–V6
Prolonged QT with U waves in V2–V3
Tall R waves in V1 with left axis deviation
Coved ST elevation in V1–V2 with right bundle branch block pattern (Correct answer)

Correct answer: Coved ST elevation in V1–V2 with right bundle branch block pattern

Brugada syndrome shows a distinctive coved-type ST elevation (>2 mm) in the right precordial leads (V1–V2) with a right bundle branch block-like pattern, predisposing to ventricular fibrillation.

Question 86: When applying limb electrodes to a patient with bilateral lower-limb amputations, where should the leg electrodes be placed?

On the lower torso or upper thighs bilaterally (Correct answer)
Skipped entirely; only chest leads are recorded
On the shoulders to balance the signal
On the upper arms instead

Correct answer: On the lower torso or upper thighs bilaterally

When limbs are absent, electrodes are repositioned to the most distal portion of the remaining limb or the corresponding torso area, maintaining left-right symmetry.

Question 87: How should the skin be prepared before placing electrodes?

Only wipe with a dry towel
Shave and clean the skin with alcohol (Correct answer)
Use adhesive tape over hair
Apply lotion to soften skin

Correct answer: Shave and clean the skin with alcohol

Proper skin preparation, including shaving excess hair and cleaning with alcohol, is vital for obtaining a high-quality ECG. Hair can obstruct electrode contact, while oils, dirt, and dead skin cells increase skin impedance. This preparation ensures optimal electrical conductivity and secure adhesion of the electrodes, minimizing artifacts and improving the clarity and accuracy of the ECG signal.

Question 88: Why is room temperature important during ECG recording?

Cold rooms below 60°F improve electrode conductivity
A comfortable temperature around 68–75°F reduces patient shivering and artifact (Correct answer)
Room temperature has no effect on ECG signal quality
Hot rooms above 85°F maximize electrode adhesion

Correct answer: A comfortable temperature around 68–75°F reduces patient shivering and artifact

A comfortable room temperature prevents patient shivering, which produces muscle tremor artifact on the ECG tracing.

Question 89: A 14-year-old athlete's ECG shows early repolarization with J-point elevation of 1 mm in the lateral leads. This is MOST likely:

Acute myocarditis requiring hospitalization
Hyperkalemia
A normal variant common in young athletes (Correct answer)
Brugada pattern type 1

Correct answer: A normal variant common in young athletes

Early repolarization with mild J-point elevation is common in young athletes and typically represents a benign normal variant related to increased vagal tone.

Question 90: When measuring the QT interval in a child with a heart rate of 120 bpm, which formula corrects for heart rate?

QTc = QT / RR²
QTc = QT × √RR
QTc = QT / √RR (Bazett's formula) (Correct answer)
QTc = QT + 0.154 × (1 − RR)

Correct answer: QTc = QT / √RR (Bazett's formula)

Bazett's formula (QTc = QT ÷ √RR) is the most widely used method to correct the QT interval for heart rate, though it tends to overcorrect at very fast rates common in children.

Question 91: A patient has a PR interval of 320 ms with all P waves followed by QRS complexes. This represents:

Third-degree AV block
Second-degree AV block, Mobitz I
Second-degree AV block, Mobitz II
First-degree AV block (Correct answer)

Correct answer: First-degree AV block

First-degree AV block is defined as a PR interval >200 ms (0.20 s) with every P wave still conducted to the ventricles.

Question 92: Which of the following artifacts can cause a false-positive diagnosis of ST-segment elevation if not recognized?

Baseline wander from respiration
60 Hz AC interference
Electrode polarization causing DC offset (Correct answer)
High-frequency muscle artifact

Correct answer: Electrode polarization causing DC offset

Electrode polarization creates a DC voltage offset that shifts the isoelectric line and can mimic ST elevation, leading to a false-positive ischemia finding.

Question 93: Which of the following electrode color codes is correct according to the AHA (American Heart Association) standard?

RA = white, LA = red, RL = black, LL = green
RA = white, LA = black, RL = green, LL = red (Correct answer)
RA = red, LA = yellow, RL = black, LL = green
RA = black, LA = white, RL = green, LL = red

Correct answer: RA = white, LA = black, RL = green, LL = red

The AHA standard assigns white to RA, black to LA, green to RL, and red to LL — recalled with the mnemonic 'White on Right, Smoke over Fire' (black over red on left).

Question 94: The mitral valve separates which two cardiac chambers?

Left ventricle and aorta
Right atrium and right ventricle
Right ventricle and pulmonary artery
Left atrium and left ventricle (Correct answer)

Correct answer: Left atrium and left ventricle

The mitral (bicuspid) valve is the atrioventricular valve located between the left atrium and left ventricle.

Question 95: A patient has an irregular rhythm with no discernible P waves and a variable ventricular rate of 90–140 bpm. The most likely diagnosis is:

Atrial flutter with variable block
Multifocal atrial tachycardia
Junctional rhythm with PVCs
Atrial fibrillation (Correct answer)

Correct answer: Atrial fibrillation

Atrial fibrillation is characterized by an irregularly irregular rhythm, absence of distinct P waves, and fibrillatory baseline activity (f waves).

Question 96: What is the purpose of using pre-gelled or conductive-gel electrodes during ECG recording?

To mark electrode placement sites permanently on the skin
To hold electrodes in place mechanically on the skin
To protect the patient from burns caused by electrical current
To reduce electrical impedance between the electrode and the skin surface (Correct answer)

Correct answer: To reduce electrical impedance between the electrode and the skin surface

Conductive gel improves electrical contact by reducing impedance, which minimizes signal noise and improves waveform clarity.

Question 97: In right-sided ECG leads (V3R–V6R), where is V4R placed?

Fifth ICS, right anterior axillary line
Mirror image of V4 on the right chest at the fifth ICS, right midclavicular line (Correct answer)
Fourth ICS, right sternal border
Same position as standard V4

Correct answer: Mirror image of V4 on the right chest at the fifth ICS, right midclavicular line

V4R is the right-side mirror of V4, placed at the fifth intercostal space on the right midclavicular line, critical for detecting right ventricular MI.

Question 98: If an ECG machine fails electrical safety testing and shows excessive leakage current, what is the correct action?

Reset the machine and retest once before removing it
Remove the machine from service immediately and tag it for biomedical repair (Correct answer)
Replace only the patient cable and return to service
Continue using the machine but document the finding

Correct answer: Remove the machine from service immediately and tag it for biomedical repair

Any device failing leakage current safety limits must be immediately taken out of service and tagged for biomedical engineering repair to prevent patient electrical hazard.

Question 99: Which lead records electrical activity between the right arm and left leg?

aVR
Lead III
Lead I
Lead II (Correct answer)

Correct answer: Lead II

Lead II is a bipolar limb lead that records the electrical activity between the right arm (negative electrode) and the left leg (positive electrode). This lead is particularly important as it often aligns with the heart's general electrical axis, providing a clear view of atrial and ventricular depolarization and repolarization. It is frequently used for rhythm strip analysis due to its prominent P, QRS, and T waves.

Question 100: On a standard 12-lead ECG recording at 25 mm/s, how many milliseconds does each small square (1 mm) on the horizontal axis represent?

20 ms
10 ms
40 ms (Correct answer)
200 ms

Correct answer: 40 ms

At the standard speed of 25 mm/s, each 1 mm small square equals 40 ms (0.04 s), and each large square (5 mm) equals 200 ms.

Question 101: Why must electrode gel be used during ECG?

To prevent skin burns
To adhere better to dry skin
To reduce muscle tremors
To enhance signal transmission (Correct answer)

Correct answer: To enhance signal transmission

Electrode gel is essential during ECG procedures because it acts as a conductive medium that significantly reduces skin impedance. By creating a better electrical connection between the skin and the electrode, the gel enhances the transmission of the heart's minute electrical signals to the ECG machine. This ensures a strong, clear signal, minimizes artifacts, and leads to more accurate and interpretable readings.

Certified Electrocardiogram (EKG) Technician (CET) Exam

The CET certification validates the knowledge and skills required to perform EKGs, prepare patients, and troubleshoot technical issues in a healthcare setting.

100

Questions

120 min

Time Limit

70%

To Pass

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