EKG Technician Interview Questions
& Model Answers, 2026

V1 in the fourth intercostal space at the right sternal border, V2 in the fourth intercostal space at the left sternal border, V4 in the fifth intercostal space at the midclavicular line, V3 midway between V2 and V4, V5 at the same horizontal level as V4 in the anterior axillary line, and V6 at the same level in the midaxillary line. Place V4 before V3. Count down from the sternal angle to find the second rib rather than guessing, and mark the positions for serial tracings so comparisons are valid.

Left and right arm reversal produces a negative P wave and QRS in lead I with an inverted complex that can mimic dextrocardia, and it changes the axis. Suspect it whenever lead I looks like an inverted mirror of the expected pattern or when aVR is positive. Do not correct it in software or by rotating the paper — replace the leads correctly and repeat the tracing. A limb lead reversal reported as an abnormal EKG generates an unnecessary cardiology workup.

Identify the pattern: fine irregular baseline suggests muscle tremor, so relax the patient, support the limbs and warm the room; a slow undulating baseline suggests respiration or loose electrodes, so re-prep the skin and replace old gel electrodes; a uniform 60-cycle interference suggests AC interference, so unplug nearby equipment and check the cable routing and the ground. Clean and dry the skin, clip rather than shave hair where policy allows, and never accept a tracing you would not want a cardiologist to read.

Do not leave the patient. Tell the nurse or physician immediately and hand over the tracing rather than filing it, because minutes matter in a STEMI pathway. Repeat or extend the tracing if asked, keep the electrodes on for serial comparison, and record the exact time. Technicians do not diagnose, but they are expected to recognise a life-threatening pattern and escalate at once — say that plainly.

Right-sided leads for suspected right ventricular infarction, usually with inferior ST elevation, mirroring V1 to V6 across the right chest with V4R at the fifth intercostal space in the right midclavicular line. Posterior leads V7, V8 and V9 for suspected posterior infarction, placed at the same horizontal level as V6 at the posterior axillary line, the mid-scapular line and the left border of the spine. Label the tracing clearly so the reader knows the leads are not standard.

Prep the skin thoroughly because a 24 to 48 hour recording fails on poor adhesion, place electrodes over bone rather than muscle to reduce artifact, secure the cables with a strain loop and tape, and verify the tracing before the patient leaves. Teach them to keep the device dry, to keep an accurate symptom diary with times, not to remove electrodes, and who to call if one falls off. Confirm the return arrangements and the recording start time.

Prepare and consent per protocol, verify medications held as instructed, place electrodes with careful skin prep in torso positions that survive movement, obtain a resting tracing supine and standing, monitor rhythm and blood pressure at each stage, watch for the termination criteria — ST changes, arrhythmia, a fall in systolic pressure, severe symptoms — and be ready to stop and call the physician. Know where the crash cart and defibrillator are and confirm they are checked before you start.

Give the finding, who you told and how fast, and the outcome. This is the story that gets EKG technicians hired, because the whole value of the role is that the abnormal tracing does not sit in a queue.

Show that you explained the test in plain terms, protected dignity during chest exposure with a drape and a chaperone where appropriate, offered a same-sex technician if requested, and did not proceed without agreement. Then say how you documented and communicated a refusal.

Describe triaging by clinical urgency — chest pain and pre-operative first, routine outpatient after — communicating realistic timings, and getting help rather than rushing placement. Say plainly that you would not compromise electrode placement to save a minute.

A mislabelled tracing, a wrong patient identifier, a lead reversal you repeated: describe how you found it, who you told, and what you changed. Tracings feed permanent records and comparisons, so honest correction matters more than a clean claim of never erring.

Anchor with the caveat: cardiovascular technologists and technicians have a BLS OEWS May 2025 median of $74,310 a year, about $35.73 an hour, with the top 10% above $121,350, but that series includes invasive and vascular technologists in the catheterisation and vascular labs, so a diagnostic EKG role typically sits in the lower part of the band. Ask what this employer's range is for the specific role before naming a figure.

Ask whether CET or CCT certification carries a differential, whether the employer pays for the exam and renewal, and whether cross-training into stress testing, Holter analysis, echocardiography or telemetry monitoring moves you up a grade. In this field the route to the top of the band runs through additional modalities, so the training commitment is the real negotiation.

Ask for the evening, night and weekend differentials as hourly amounts, whether the role carries call for stat tracings, whether overtime is available and how it is approved, and whether you would be expected to cover telemetry monitoring as well as diagnostics. Guaranteed hours matter for hourly roles, so confirm whether the position is full time with a fixed schedule.