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CET · 24% of the exam

EKG Analysis and Interpretation practice questions

10 free EKG Analysis and Interpretation questions for the Certified EKG Technician (CET) exam, each with the correct answer and an explanation for every option.

Start the questionsFree 10-question CET quiz

What this domain covers

Reading the tracing: working out rate and rhythm, measuring intervals and recognising rhythms that need urgent attention.

Exam weight
24%
On a real exam
≈ 29 questions
In our bank
143 questions

Topics that come up most

  • Heart rate calculation methods
  • Measuring PR, QRS and QT intervals
  • Sinus, atrial, junctional and ventricular rhythms
  • Heart blocks and paced rhythms
  • Life-threatening rhythms and when to notify the provider

How to study it

Use the same five steps on every rhythm (rate, regularity, P waves, PR interval, QRS width) and keep a table of the normal values; questions give the measurements in words and expect you to name the rhythm.

Sample EKG Analysis and Interpretation questions

Try each one before opening the answer. Original questions written to the official exam objectives.

  1. Question 1

    The QT interval is measured from the start of the QRS to the:

    • AEnd of the T wave
    • BStart of the P wave
    • CPeak of the R wave
    • DNext QRS complex
    Show answer and explanation

    Answer: A) End of the T wave

    • ACorrect. It reflects ventricular depolarization and repolarization.
    • BIncorrect. This is not the QT endpoint.
    • CIncorrect. This is too short.
    • DIncorrect. That is the R-R interval.

  2. Question 2

    If lead I is positive and aVF is negative, the axis is:

    • AExtreme axis
    • BNormal
    • CRight axis deviation
    • DLeft axis deviation
    Show answer and explanation

    Answer: D) Left axis deviation

    • AIncorrect. Both would be negative.
    • BIncorrect. Both would be positive.
    • CIncorrect. Lead I would be negative.
    • DCorrect. It points up and to the left.

  3. Question 3

    The top of a newly printed 12-lead EKG shows the machine statement "Atrial fibrillation." How should the technician treat this statement?

    • AAs a confirmed diagnosis that can be filed in the chart as final
    • BAs proof the tracing is artifact-free because software analyzed it
    • CAs a preliminary computer finding that a qualified provider must confirm
    • DAs a reason to delete the tracing and repeat it before anyone reviews it
    Show answer and explanation

    Answer: C) As a preliminary computer finding that a qualified provider must confirm

    Automated EKG interpretation is a preliminary read based on waveform criteria. A qualified provider must review and confirm it before it is treated as a diagnosis.

    • AIncorrect. Machine statements aren't final diagnoses. They can be wrong and must be reviewed by a qualified provider.
    • BIncorrect. The software can misread artifact, for example as an arrhythmia. The technician still has to check tracing quality.
    • CCorrect. Digital EKG machines generate preliminary findings from waveform criteria. A qualified provider has to review and confirm them.
    • DIncorrect. The technician checks quality and follows facility protocol for reporting. A possible abnormal finding is not a reason to delete the tracing.

  4. Question 4

    A rhythm under 100 bpm with changing P-wave shapes is likely:

    • AAtrial flutter
    • BWandering atrial pacemaker
    • CSinus rhythm
    • DVF
    Show answer and explanation

    Answer: B) Wandering atrial pacemaker

    • AIncorrect. That has flutter waves.
    • BCorrect. Above 100 it's multifocal atrial tachycardia.
    • CIncorrect. It has one P shape.
    • DIncorrect. There are organized QRS complexes.

  5. Question 5

    The ST segment is measured from the:

    • AJ point to T
    • BP wave to QRS
    • CR peak to P wave
    • DT wave to next P
    Show answer and explanation

    Answer: A) J point to T

    • ACorrect. The J point is where the QRS ends.
    • BIncorrect. That is the PR segment.
    • CIncorrect. This is not the ST segment.
    • DIncorrect. This is the TP segment.

  6. Question 6

    Why should asystole be confirmed in more than one lead?

    • AA flat line in one lead may be a loose electrode, low gain, or fine VF
    • BAsystole shows a flat line in limb leads but not in chest leads
    • CA second lead is needed to calculate the ventricular rate first
    • DTwo-lead confirmation is required before delivering a defibrillation shock
    Show answer and explanation

    Answer: A) A flat line in one lead may be a loose electrode, low gain, or fine VF

    A flat line in a single lead can come from a loose electrode, low gain, or fine VF, so asystole is confirmed in at least two leads. Asystole itself is not shockable.

    • ACorrect. Fine ventricular fibrillation can look flat in one lead, and a disconnected electrode or low gain setting can also produce a flat line. Checking a second lead, plus the connections and gain, confirms true asystole.
    • BIncorrect. True asystole means there is no ventricular electrical activity, so the tracing is flat in every lead. That is why a flat line in one lead only, with activity in others, is not asystole.
    • CIncorrect. Asystole has no ventricular complexes, so there is no rate to calculate. The second lead is used to rule out artifact or fine VF.
    • DIncorrect. Asystole is not a shockable rhythm. Once asystole is confirmed in at least two leads, defibrillation should not be attempted.

  7. Question 7

    P waves and QRS complexes that occur independently of each other indicate:

    • AThird-degree AV block
    • BFirst-degree AV block
    • CSinus rhythm
    • DAtrial flutter
    Show answer and explanation

    Answer: A) Third-degree AV block

    • ACorrect. Complete heart block shows AV dissociation.
    • BIncorrect. Every P conducts.
    • CIncorrect. P and QRS are linked.
    • DIncorrect. This has flutter waves.

  8. Question 8

    A regular narrow-QRS rhythm at 45 bpm with no P waves is likely:

    • AJunctional escape rhythm
    • BSinus tachycardia
    • CVentricular tachycardia
    • DAtrial flutter
    Show answer and explanation

    Answer: A) Junctional escape rhythm

    • ACorrect. The AV junction fires at 40 to 60.
    • BIncorrect. The rate is slow.
    • CIncorrect. The QRS is narrow and the rate slow.
    • DIncorrect. There are no flutter waves.

  9. Question 9

    Three or more PVCs in a row at a fast rate are considered:

    • ABigeminy
    • BA couplet
    • CA run of VT
    • DSinus rhythm
    Show answer and explanation

    Answer: C) A run of VT

    • AIncorrect. That alternates with normal beats.
    • BIncorrect. That is two.
    • CCorrect. Three or more consecutive PVCs is ventricular tachycardia.
    • DIncorrect. These are ventricular beats.

  10. Question 10

    ST elevation in leads II, III and aVF points to the:

    • ASeptal wall
    • BLateral wall
    • CInferior wall
    • DAnterior wall
    Show answer and explanation

    Answer: C) Inferior wall

    • AIncorrect. That is V1, V2.
    • BIncorrect. That is I, aVL, V5, V6.
    • CCorrect. These leads view the inferior heart.
    • DIncorrect. That is V3, V4.

EKG Analysis and Interpretation: FAQs

How much of the CET exam is EKG Analysis and Interpretation?

EKG Analysis and Interpretation is 24% of the CET exam by the official exam guide's weighting, which on a 120-question form works out to roughly 29 questions. The real exam's exact split varies by form.

What does the EKG Analysis and Interpretation domain cover?

Reading the tracing: working out rate and rhythm, measuring intervals and recognising rhythms that need urgent attention.

How should I study EKG Analysis and Interpretation for CET?

Use the same five steps on every rhythm (rate, regularity, P waves, PR interval, QRS width) and keep a table of the normal values; questions give the measurements in words and expect you to name the rhythm.

Where can I practise more EKG Analysis and Interpretation questions?

This page has 10 free EKG Analysis and Interpretation questions with answers. The ExamWize CET question bank has 143 questions in this domain. Every practice exam result breaks your score down by domain, and Review Mode re-drills the questions you missed.

Other CET topics

Also: 15 free questions across all topics, the CET cheat sheet and the study guide.

Get EKG Analysis and Interpretation exam-ready

The full CET bank has 143 EKG Analysis and Interpretation questions. Timed practice exams match the real exam's length and domain weights, every result shows your score per domain, and Review Mode re-drills the questions you missed.

See the full CET practice examsTake the free diagnostic

Not affiliated with NHA; questions are original, written from the official exam outline, and never copied from the real exam.