CET NHA Certified EKG Technician - Set 4 - Part 1

Correct Answer: Reduce skin impedance for clear signals

Skin preparation reduces impedance by removing oils, dead skin, and debris that block electrical contact between the electrode and the body. A low-impedance interface produces a cleaner tracing with less artifact and better adhesion. Option a is incorrect because cooling the chest is not a goal of skin preparation and can actually trigger shivering that produces somatic tremor artifact. Temperature management before an EKG aims for comfortable warmth, not cooling. Option b is incorrect because warming the patient is a comfort and artifact-prevention measure, not the specific function of skin prep. Warming addresses shivering separately from the prep steps that target the electrode contact area. Option d is incorrect because the visual appearance of the chest area is not a clinical concern of skin preparation. Cosmetic concerns are unrelated to the electrical and adhesion goals the prep steps address.

Correct Answer: Cleanse the area with alcohol and dry it

Cleansing the area with an alcohol pad removes oils and lotions that prevent electrode adhesion and conductivity. After cleansing, the skin should be dried fully because wet skin also degrades the contact between electrode gel and the body. Option b is incorrect because applying electrodes directly over lotion blocks the gel from contacting the skin and causes both poor adhesion and tracing artifact. Working around the obstacle rather than removing it produces a poor-quality recording. Option c is incorrect because canceling a test over surface lotion is an overreaction when a simple alcohol cleanse solves the problem in seconds. Delaying care needlessly creates a scheduling and clinical burden the situation does not require. Option d is incorrect because gauze on top of the skin still leaves lotion underneath where the electrode needs to make contact. The barrier remains, and adding gauze does nothing to restore the conductive surface the electrode requires.

Correct Answer: Shave a small area at each electrode site

Shaving a small area at each electrode site with a fresh disposable razor allows the electrode to sit flush against the skin and adhere properly. Only the area directly under each electrode needs to be shaved. Option a is incorrect because pressing harder cannot eliminate the air gap that hair creates between the gel and the skin. Hair physically interrupts contact regardless of pressure applied during electrode placement. Option b is incorrect because skipping leads produces an incomplete tracing that may miss findings the lead would have shown. A standard twelve-lead EKG requires all twelve leads to be useful for interpretation. Option c is incorrect because taping electrodes over hair still leaves the hair between the gel and the skin, even if the electrode is held in place. Tape addresses adhesion but not the underlying contact problem hair creates.

Correct Answer: Apply benzoin tincture around electrodes and tape

Applying benzoin tincture around the electrodes acts as a skin adherent that helps electrodes stick despite ongoing sweating, and taping over the electrode adds mechanical security. Specialized sweat-resistant electrodes are another option in stress testing. Option a is incorrect because cold water rinses can trigger shivering and somatic tremor artifact while doing nothing to fix the adhesion problem. Cooling the skin treats the wrong issue and creates a new one. Option c is incorrect because pressing electrodes for long periods does not overcome the moisture barrier that sweat creates under the adhesive. Time at the surface does not change the chemistry that makes adhesive fail in moisture. Option d is incorrect because waiting for a diaphoretic patient to stop sweating may not happen at all during an urgent test. Diaphoresis can be a feature of the patient's condition and must be worked around rather than waited out.

Correct Answer: Use minimal abrasion and peel electrodes gently

Using minimal skin abrasion during preparation and peeling electrodes gently parallel to the skin during removal protects fragile elderly skin from tears. Hypoallergenic adhesive removal wipes can also reduce trauma during removal in this population. Option a is incorrect because the strongest adhesive available is exactly the wrong choice for fragile elderly skin because it increases the risk of skin tears on removal. Adhesive strength must match the patient's skin tolerance, not maximum stickiness. Option b is incorrect because vigorous scrubbing damages fragile skin and can break the surface before electrodes are even placed. Gentle prep is the appropriate intensity for elderly patients with thin, easily torn skin. Option d is incorrect because adding tape over each electrode increases removal trauma later and provides no benefit during preparation. Extra adhesive on fragile skin compounds the very problem the question asks the technician to prevent.

Correct Answer: Supine with arms relaxed at sides

The standard resting position is supine on an examination table with arms relaxed at the sides and legs uncrossed. Slight head elevation is acceptable for comfort, and the chest, wrists, and ankles must be accessible. Option a is incorrect because standing produces significant muscle tension and artifact that the supine position avoids. Standing positions are not used for routine resting EKGs because they undermine tracing quality. Option b is incorrect because sitting forward with the chest exposed is a position used for some auscultation but not for resting EKG recording. The supine position is the standard for the routine tracing because of the muscle relaxation it offers. Option c is incorrect because lying prone places the patient face down and blocks access to the chest leads entirely. Prone positioning would make a chest-lead EKG impossible to perform.

Correct Answer: Tilt the patient slightly to the left side

Late-term pregnancy can cause aortocaval compression in the supine position as the gravid uterus presses on the inferior vena cava. A left lateral tilt of about fifteen to thirty degrees relieves the pressure and restores venous return. Option b is incorrect because continuing supine despite the patient's symptoms ignores the aortocaval compression that is causing the lightheadedness. Letting the patient stay symptomatic creates a safety risk that has a simple positioning fix. Option c is incorrect because sitting completely upright would alter the standard recording position more than necessary and change the EKG axis. A small left lateral tilt is the targeted adjustment for aortocaval compression rather than a full posture change. Option d is incorrect because prone position is even less safe for a pregnant patient and impossible for chest lead access. Prone offers none of the relief that the left lateral tilt provides while making the EKG impossible.

Correct Answer: Place on the stump close to the trunk

For amputees, the limb electrode is placed on the stump as close to the trunk as possible, or on the corresponding shoulder if the entire limb is missing. The technician should document the deviation for the interpreter. Option a is incorrect because skipping the right arm lead leaves an incomplete tracing missing both lead one and the augmented voltage right arm view. Incomplete data forces the interpreter to work with less than the standard set. Option b is incorrect because placing the electrode on the left arm twice would not produce the right arm signal needed for the standard limb leads. Duplicating one limb does not substitute for measurements from the missing side. Option d is incorrect because the right ear is not an accepted limb electrode position and would produce wildly different recordings from the standard. Ad hoc placement at the head invents data that does not match accepted EKG conventions.

Correct Answer: Move limb electrodes more proximally toward trunk

Moving the limb electrodes more proximally toward the trunk, such as toward the shoulder and hip, reduces tremor artifact because the larger proximal muscles move less than the hands and feet. Document the modified positions on the tracing. Option a is incorrect because holding a patient's hands firmly down can be perceived as aggressive and rarely calms the involuntary movements of Parkinson's disease. Restraint also introduces new tension that can produce its own artifact. Option c is incorrect because lowering the gain reduces both the artifact and the genuine cardiac signal, producing a tracing too small to interpret reliably. Gain changes scale everything together rather than removing only the unwanted noise. Option d is incorrect because skipping the limb leads removes half of the twelve-lead set and leaves the tracing incomplete for interpretation. The proper response is to adapt placement rather than abandon the limb lead system entirely.

Correct Answer: Position in semi-Fowler's and document

Positioning the patient in semi-Fowler's or high-Fowler's with the head elevated thirty to ninety degrees allows the EKG to be obtained while respecting respiratory limits. The position should be documented because it can alter the EKG axis. Option a is incorrect because forcing a patient with orthopnea to lie supine causes acute respiratory distress that may worsen during the test. Patient safety overrides the convenience of the supine position whenever orthopnea is present. Option b is incorrect because skipping the EKG denies clinically indicated information when a simple positioning adjustment can solve the problem. Rescheduling indefinitely also leaves the ordering clinician without the test data they requested. Option c is incorrect because a 3-lead rhythm strip is not equivalent to a 12-lead EKG and does not satisfy a 12-lead order. Substituting one for the other would produce an inadequate study for the clinical question being asked.

Correct Answer: Place all four limbs in equivalent bilateral positions

The four limb electrodes should sit in bilaterally equivalent positions on the wrists and ankles, or in another consistent location such as the shoulders and hips for special patients. Asymmetry between sides distorts the limb lead vectors. Option b is incorrect because placing the arm electrodes on the chest near the V leads would convert the limb leads into the Mason-Likar configuration intended only for stress testing. Standard resting EKGs use the wrist position for arm electrodes. Option c is incorrect because placing legs above the ankles while placing arms at the shoulders breaks bilateral equivalence by pairing different body regions. The principle requires both arms together and both legs together. Option d is incorrect because convenience placement ignores the standardization that makes the EKG interpretable. Inconsistent placement produces tracings that cannot be compared to prior recordings or interpreted against standard criteria.

Correct Answer: The sternal angle of Louis

The sternal angle of Louis is the ridge where the manubrium meets the body of the sternum, and the second rib attaches at this level. The technician counts down from this landmark to find the fourth intercostal space. Option a is incorrect because the xiphoid process sits at the bottom of the sternum and does not directly identify a specific intercostal space. Counting up from the xiphoid is harder than using the angle of Louis shortcut. Option b is incorrect because the clavicle is a landmark for the midclavicular line and the first rib's general region, not for the fourth intercostal space directly. The clavicle does not pinpoint the relevant space. Option d is incorrect because the seventh cervical vertebra is a posterior landmark used for counting spinous processes from the neck, not for identifying intercostal spaces on the anterior chest. Anterior landmarks are needed for precordial placement.

Correct Answer: V2 and V4 first

Placing V2 and V4 first allows the technician to identify V3 as the midpoint along the diagonal line between them. This sequencing keeps V3 in the correct anatomical position relative to its neighbors on either side. Option a is incorrect because V1 and V6 are far apart on the chest and do not bracket V3 directly. V3 sits between V2 above and V4 below, not between V1 and V6. Option b is incorrect because V2 and V5 are not the neighbors that directly bracket V3, even though they are closer than V1 and V6. V3 sits between V2 and V4 specifically. Option c is incorrect because V1 and V4 do not bracket V3 either; V3 sits between V2 and V4. V1 sits on the other side of V2 from V3 and is too lateral to anchor V3's position.

Correct Answer: The midaxillary line on the left

V6 sits on the midaxillary line on the left side, on the same horizontal level as V4 and V5. The midaxillary line runs vertically through the apex of the axilla and provides the most lateral precordial view. Option b is incorrect because the midclavicular line drops straight down from the middle of the clavicle and marks where V4 sits. V6 sits much further lateral, out toward the axilla rather than under the collarbone. Option c is incorrect because V5 already occupies the anterior axillary line on the chest. Placing V6 at that same vertical line would duplicate V5 and skip the more lateral position that V6 is designed to provide. Option d is incorrect because behind the patient on the back, the posterior axillary line hosts V7 when posterior leads are needed. V6 stays on the lateral chest wall, never wrapping all the way around to the back.

Correct Answer: Reversal of the right and left arm electrodes

An inverted P wave in lead one paired with an upright P wave in aVR is the classic pattern of right and left arm electrode reversal. Before assuming a clinical diagnosis, the technician should check electrode placement and re-record. Option a is incorrect because acute inferior myocardial infarction produces ST elevation in leads two, three, and aVF rather than this specific arm-reversal pattern in lead one and aVR. The inferior MI presentation does not match the described findings. Option c is incorrect because severe hypothermia tends to produce Osborn or J waves and bradycardia rather than the inverted P pattern in lead one. Hypothermia changes look very different from the reversal pattern described in the scenario. Option d is incorrect because hyperkalemia produces peaked T waves and eventually wide QRS and sine-wave patterns rather than inverted P waves in lead one. The hyperkalemia pattern affects different waveforms than the ones described here.

Correct Answer: Under the breast tissue against the chest wall

V3 through V6 should be placed under the breast tissue, lifting the breast gently if necessary, so the electrodes sit against the chest wall directly. Placing electrodes on top of breast tissue attenuates the signal. Option a is incorrect because placing electrodes on top of breast tissue puts a layer of tissue between the chest wall and the electrode, which attenuates the cardiac signal. ST segment evaluation in particular becomes unreliable through breast tissue. Option b is incorrect because moving V3 through V6 to the side of the chest entirely abandons the standard precordial positions that the twelve-lead EKG depends on. Lateral relocation defeats the regional view those leads are meant to provide. Option c is incorrect because the back is the location for posterior leads V7 through V9, not for the standard precordial leads. Moving anterior leads to the back would convert them into different leads and change the recording entirely.

Correct Answer: Prior anterior MI or chest electrode placement too high

Poor R-wave progression with persistent S waves in V5 and V6 often suggests prior anterior wall myocardial infarction or technical error from placing chest electrodes too high on the chest. Verifying placement is the first troubleshooting step. Option a is incorrect because normal anatomy produces progressive R-wave growth from V1 to V5 or V6, with a transition zone around V3 or V4. Persistent S waves in V5 and V6 do not match the normal progression pattern. Option b is incorrect because gain set too high would amplify all signals proportionally rather than altering the R-wave progression specifically. Gain effects are systemic across the tracing and do not produce regional progression problems. Option d is incorrect because electromagnetic interference appears as a regular sine-wave overlay on the entire tracing rather than as a specific R-wave progression pattern. Interference looks different from a progression abnormality.

Correct Answer: Just above the cast on the upper arm

When a cast covers the standard limb electrode site, the technician places the electrode just above the cast on the same limb to preserve bilateral equivalence. The deviation should be documented on the tracing for the interpreting clinician. Option b is incorrect because the cast surface does not transmit the electrical signal from the body and would produce a useless tracing. Plaster or fiberglass blocks the electrical contact the electrode needs to function. Option c is incorrect because placing the electrode on the opposite left arm gives two signals from the left side and no signal from the right. Lead one and other limb leads depend on a true right arm signal. Option d is incorrect because skipping the right arm electrode removes lead one and the augmented voltage right arm view entirely. An incomplete limb lead set undermines the standard twelve-lead interpretation.

Correct Answer: Minimal change because RL is ground

Reversing the right leg and left leg electrodes typically produces minimal change because the right leg electrode acts as a ground reference. Some subtle effects may appear, but major lead morphologies remain largely intact. Option a is incorrect because complete inversion of lead one is the signature of right and left arm electrode reversal rather than leg reversal. Lead one is constructed from arm electrodes and is most affected by arm switches. Option b is incorrect because the QRS complex remains visible after a leg reversal, although small artifacts may appear. Reversing legs does not eliminate the QRS, which depends on multiple electrodes including arm leads. Option d is incorrect because massive ST elevation is a finding of acute injury rather than a result of leg electrode reversal. Electrode swaps produce predictable lead pattern shifts rather than dramatic ST changes.

Correct Answer: Apparent rightward axis and false anterior changes

Placing V1 and V2 too high can produce an apparent rightward axis, abnormal R-wave progression, and may falsely suggest anterior myocardial infarction or right ventricular hypertrophy. The technician should verify intercostal counting before reporting the tracing. Option a is incorrect because AC interference is a sixty hertz electrical artifact unrelated to electrode placement height. The two phenomena have different causes and produce different patterns on the tracing. Option b is incorrect because wandering baseline drift comes from patient movement, breathing, or loose electrodes rather than from misplaced lead positions. Drift looks different from a regional waveform abnormality and has different causes. Option c is incorrect because somatic tremor artifact comes from muscle contractions producing fine jagged baseline. Tremor pattern and high-placement misreading are entirely different findings caused by entirely different problems.