EKG and cardiovascular testing on the CCMA

These are short and exact. If you miss a placement item, look at the diagram again before the next one.

1. Question 1

   During an EKG, the patient becomes unresponsive, and the tracing shows chaotic waves with no QRS complexes. What should the MA do first?

   • AActivate emergency response and start CPR
   • BCheck the leads for a loose electrode first
   • CRaise the patient's legs and recheck in 1 minute
   • DRun a rhythm strip to hand to the provider
   Answer & explanation

   Answer: A. Activate emergency response and start CPR

   An unresponsive patient with a chaotic tracing and no QRS complexes is in ventricular fibrillation, a shockable cardiac arrest, so the MA calls for help, starts CPR, and uses the AED as soon as it arrives. Checking the leads is tempting because artifact can look chaotic, but an unresponsive patient is treated as in arrest first. Printing a strip or raising the legs delays defibrillation.

   • Correct: an unresponsive patient in VF is in cardiac arrest, so call for help, start CPR, get the AED.
   • Artifact can look chaotic, but an unresponsive patient is treated as an arrest first.
   • Raising the legs is for fainting or shock, not a pulseless rhythm, and it wastes a minute.
   • Printing a strip delays defibrillation, the treatment that matters most in VF.

2. Question 2

   On a 12-lead EKG, the standardization mark is only 5 mm tall. What does this mean?

   • AThe patient's heart has low voltage
   • BPaper speed is set to 50 mm/s
   • CNormal standard; the mark is always 5 mm
   • DGain is at half standard (5 mm/mV)
   Answer & explanation

   Answer: D. Gain is at half standard (5 mm/mV)

   At standard gain, a 1 mV calibration pulse is 10 mm tall (10 mm/mV), so a 5 mm mark means the gain was set to half standard and every wave is shown half size. Low voltage is tempting, but the calibration pulse is generated by the machine, not the heart. Paper speed affects the width of waves, not the height of the calibration mark.

   • The calibration pulse comes from the machine, so its height says nothing about the heart's voltage.
   • Paper speed changes width along the time axis, not the height of the calibration mark.
   • Standard calibration is 10 mm per 1 mV; a 5 mm mark is not normal.
   • Correct: 5 mm for 1 mV means half gain, so every wave is drawn at half size.

3. Question 3

   A patient's chest is hairy where the V4 electrode must go, and the electrode will not stick. What should the MA do?

   • AHold the electrode on with extra tape
   • BMove V4 to a hairless spot one space lower
   • CClip the hair at the site, then apply it
   • DApply lotion so the electrode lies flat
   Answer & explanation

   Answer: C. Clip the hair at the site, then apply it

   Hair at the site is clipped or shaved, and the skin cleaned and dried, so the electrode has full contact at the correct landmark. Moving V4 to a hairless spot is tempting, but a misplaced electrode changes the tracing. Tape over hair still leaves poor contact and artifact, and lotion keeps electrodes from sticking.

   • Tape over hair still leaves poor skin contact, which shows up as artifact.
   • Moving V4 off its landmark changes the tracing; placement matters more than convenience.
   • Correct: clip the hair, clean and dry the skin, then place V4 at the fifth intercostal space, midclavicular.
   • Lotion leaves a film that keeps electrodes from sticking at all.

4. Question 4

   A patient with heart failure becomes short of breath lying flat for a 12-lead EKG. What should the MA do?

   • ARaise the head of the table and note it
   • BKeep the patient flat so the leads are accurate
   • CPostpone the EKG until breathing improves
   • DRecord the EKG with the patient standing
   Answer & explanation

   Answer: A. Raise the head of the table and note it

   Supine is standard, but a patient who cannot breathe lying flat can be recorded in semi-Fowler's position, with the position noted on the tracing so it can be compared later. Insisting on a flat position is tempting because it is the textbook setup, but it puts the patient in distress and causes muscle artifact. Postponing delays a needed test, and standing adds movement artifact.

   • Correct: semi-Fowler's is acceptable for a patient who cannot lie flat, as long as the position is noted.
   • Insisting on flat is textbook, but it distresses the patient and adds muscle artifact.
   • Postponing delays an ordered test when a simple position change solves the problem.
   • Standing adds movement artifact and is not a resting 12-lead position.

5. Question 5

   A patient is fitted with a Holter monitor. Which instruction is correct?

   • AIt will deliver a shock if needed
   • BKeep a symptom diary and avoid bathing
   • CWear it for exactly two hours only
   • DRemove the electrodes whenever you feel well
   Answer & explanation

   Answer: B. Keep a symptom diary and avoid bathing

   A Holter records continuously for about 24–48 hours while the patient keeps a diary of symptoms and activities, and avoids bathing so the electrodes stay in place. It only records; it does not deliver any therapy.

   • A Holter only records; delivering a shock is what a defibrillator, implanted or wearable, does.
   • Correct: a symptom diary lets the provider match events to the tracing, and staying dry keeps electrodes on.
   • Holter monitoring usually runs 24–48 hours, not a fixed two hours.
   • Removing electrodes when well leaves gaps in the very baseline the provider needs.

6. Question 6

   During a treadmill stress test, which finding means the test should be stopped?

   • AFaster breathing and mild sweating
   • BThe patient develops chest pain
   • CHeart rate reaches the target rate
   • DSystolic BP rises from 130 to 160
   Answer & explanation

   Answer: B. The patient develops chest pain

   Chest pain, significant ST changes, arrhythmias, or a drop in blood pressure are reasons to stop a stress test. Reaching the target heart rate is the goal of the test, not a danger sign, though it tempts because it sounds like a limit. Faster breathing, sweating, and a rise in systolic pressure are normal responses to exercise.

   • Faster breathing and sweating are normal responses to exercise, not reasons to stop.
   • Correct: chest pain is a stop criterion, along with ST changes, arrhythmias, or a fall in blood pressure.
   • Reaching target heart rate is the goal of the test, even though it sounds like a limit.
   • A rise in systolic pressure with exercise is expected; a drop would be the warning sign.

7. Question 7

   A rhythm strip shows one early, wide, bizarre QRS complex with no P wave before it, and then normal beats resume. What is this beat?

   • AVentricular tachycardia
   • BIrregularly irregular atrial fibrillation
   • CPremature ventricular contraction
   • DPremature atrial contraction
   Answer & explanation

   Answer: C. Premature ventricular contraction

   An early beat with a wide, bizarre QRS and no preceding P wave comes from the ventricles, so it is a premature ventricular contraction (PVC). A premature atrial contraction is also early but has a P wave and a narrow QRS. Ventricular tachycardia needs three or more wide beats in a row, and atrial fibrillation is irregular throughout with no P waves.

   • V-tach needs at least three wide beats in a row; one early wide beat and then normal rhythm is not it.
   • A-fib stays irregular across the whole strip with no P waves anywhere, not one odd beat among normal ones.
   • Correct: early, wide, bizarre, and no P wave in front means the beat started in the ventricles, so it is a PVC.
   • A premature atrial beat also arrives early, but it has a P wave and a narrow QRS, unlike this one.

8. Question 8

   How many electrodes are placed on the patient to record a standard 12-lead EKG?

   • ATen electrodes
   • BSix electrodes
   • CTwelve electrodes
   • DSixteen electrodes
   Answer & explanation

   Answer: A. Ten electrodes

   Ten electrodes (four limb and six chest) generate the twelve views, or leads, of a standard 12-lead EKG. The number twelve refers to the leads recorded, not the electrodes applied.

   • Correct: four limb and six chest electrodes produce twelve different views, called leads.
   • Six is only the chest electrodes; the four limb electrodes are needed too.
   • Twelve is the number of leads, the views, not the electrodes placed on the skin.
   • Sixteen exceeds the standard setup; extra right-sided or posterior electrodes belong to specialized lead sets.

9. Question 9

   The chest (V) lead cables are attached to the wrong precordial positions. Which change is most likely seen on the tracing?

   • AComplete loss of all atrial P waves
   • BPoor R-wave progression across the chest leads
   • CSudden shortening of the QT interval
   • DA uniformly flat isoelectric baseline throughout
   Answer & explanation

   Answer: B. Poor R-wave progression across the chest leads

   Mis-ordering the precordial electrodes disrupts the normal, smooth R-wave progression from V1 to V6 and distorts the waveforms. Recognizing abnormal progression should prompt the MA to verify placement and repeat the tracing.

   • P waves come from the atria and appear regardless of chest-lead order; they do not vanish.
   • Correct: swapped chest leads break the smooth R-wave growth from V1 to V6, so check placement and repeat.
   • The QT interval reflects ventricular timing, not where the chest electrodes sit.
   • A flat line suggests a disconnected lead or arrest, not misordered chest leads.

10. Question 10

    A 12-lead EKG was accidentally recorded at 50 mm/s. Compared with a standard tracing, how will it look?

    • ATaller complexes; the rate is unchanged
    • BNarrower complexes; the rate looks faster
    • CWider complexes; the rate looks slower
    • DNo visible change in the complexes
    Answer & explanation

    Answer: C. Wider complexes; the rate looks slower

    Standard paper speed is 25 mm/s, so running at 50 mm/s spreads each complex over twice the distance, making waves look wider and the rate look slower. Candidates who reverse the effect choose 'narrower and faster', which is what a slower paper speed would do. Height is set by the gain (10 mm/mV), not by paper speed.

    • Height depends on gain, not paper speed, so complexes do not get taller.
    • Narrower and faster is the reverse effect, which a slower paper speed would cause.
    • Correct: doubling paper speed spreads each complex over twice the distance, so waves look wider and the rate slower.
    • Changing paper speed always changes how the tracing looks; it is not a neutral setting.

11. Question 11

    The right-arm and left-arm electrodes are accidentally reversed. Which finding on the tracing suggests this error?

    • APeaked T waves in the limb leads
    • BNegative P wave and QRS in lead I
    • CST-segment elevation across all chest leads
    • DA prolonged QT interval in every lead
    Answer & explanation

    Answer: B. Negative P wave and QRS in lead I

    Reversing the right-arm and left-arm electrodes inverts lead I, producing a negative P wave and QRS that can mimic dextrocardia. Recognizing this prompts the MA to check and correct electrode placement and repeat the tracing.

    • Peaked T waves suggest high potassium, not a reversed pair of arm electrodes.
    • Correct: reversing the arm electrodes inverts lead I, so P and QRS point down, mimicking dextrocardia.
    • Diffuse ST elevation in the chest leads is not caused by swapping the arm electrodes.
    • A prolonged QT reflects drugs or electrolytes, not where the arm electrodes are placed.

12. Question 12

    Where should the limb electrodes be placed for a routine 12-lead EKG?

    • AOver bony prominences such as the wrist bones
    • BOn the chest near each shoulder and hip
    • CAnywhere on the limbs, differing left and right
    • DFleshy areas of the limbs, away from bone
    Answer & explanation

    Answer: D. Fleshy areas of the limbs, away from bone

    Limb electrodes go on fleshy, flat areas of the arms and legs, away from bone, and in matching positions on both sides for a clean, symmetric signal. Bony prominences give poor contact and more artifact. Torso placement near the shoulders and hips is a modified setup for exercise or monitoring and changes a resting 12-lead, and uneven left-right positions distort the limb leads.

    • Bone gives poor contact and more artifact, so electrodes avoid bony prominences.
    • Torso placement is a modified setup for monitoring or exercise; it changes a resting 12-lead.
    • Uneven left and right positions distort the limb leads; sites should be symmetric.
    • Correct: fleshy, flat areas of the limbs, away from bone, matched on both sides.

13. Question 13

    A medical assistant is reviewing an EKG rhythm strip that shows an irregularly irregular rhythm, no distinct P waves, and narrow QRS complexes. Which method should the MA use to count the heart rate?

    • ADivide 300 by the large boxes between two R waves
    • BCount the QRS complexes in 10 seconds and divide by 6
    • CCount the R waves in 6 seconds and multiply by 10
    • DDivide 1500 by the small boxes between two R waves
    Answer & explanation

    Answer: C. Count the R waves in 6 seconds and multiply by 10

    When R-R intervals vary, as in atrial fibrillation, the rate is estimated by counting R waves in a 6-second strip and multiplying by 10. The 1500 and 300 methods measure a single R-R interval, so they give different answers depending on which pair of beats is chosen. Counting complexes in 10 seconds is fine only if the count is multiplied by 6; dividing gives a meaningless number. The MA reports the rate and rhythm to the provider, who interprets them.

    • The 300 method uses one R-R interval, which varies beat to beat in an irregular rhythm.
    • Ten seconds of complexes must be multiplied by six; dividing gives a meaningless number.
    • Correct: in an irregular rhythm, count R waves in a 6-second strip and multiply by 10.
    • The 1500 method also measures one interval, so the rate changes with whichever pair is chosen.

14. Question 14

    On a standard EKG at 25 mm/s, two consecutive R waves are 5 large boxes apart. What is the heart rate?

    • A60 bpm
    • B75 bpm
    • C100 bpm
    • D50 bpm
    Answer & explanation

    Answer: A. 60 bpm

    Each large box is 0.20 second, so 5 large boxes equal 1 second between beats, which is 60 beats per minute (300 ÷ 5 = 60). A rate of 75 bpm comes from dividing 300 by 4 boxes, a miscount of one box. A rate of 100 bpm would need 3 large boxes between R waves.

    • Correct: five large boxes equal one second between beats, so 300 divided by 5 is 60 bpm.
    • 75 bpm comes from dividing 300 by 4, a miscount of one large box.
    • 100 bpm would need only 3 large boxes between the R waves.
    • 50 bpm would need 6 large boxes, a miscount in the other direction.

15. Question 15

    Just before recording a 12-lead EKG, what should the MA tell the patient?

    • ATake a deep breath and hold it until it's done
    • BRest your clasped hands on your chest
    • CLie still, breathe normally, and don't talk
    • DKeep talking so you stay relaxed and calm
    Answer & explanation

    Answer: C. Lie still, breathe normally, and don't talk

    The patient lies still with arms at the sides, breathes normally, and does not talk, because muscle movement creates artifact. Holding a deep breath is tempting because it sounds like keeping still, but it tenses the chest muscles and cannot be held for the full recording. Hands resting on the chest and talking both add muscle artifact.

    • Breath-holding sounds like staying still, but it tenses the chest and nobody can hold it through the whole recording.
    • Hands on the chest keep the arm muscles working right over the leads, which shows up as artifact.
    • Correct: still, quiet, normal breathing with arms at the sides gives the cleanest tracing with the least muscle noise.
    • Talking may feel calming, but every word moves chest muscles and leaves jagged artifact on the strip.