How to Perform an EKG: A Step-by-Step Guide for Clinical Staff

An electrocardiogram often abbreviated as EKG or ECG is a common procedure in outpatient and inpatient care settings. As common as it is, it can be easy to become overconfident and leave room for a small technique error that can have an impact on the accuracy of the final reading. This can be a result of a misplaced lead, a rushed capture, or incomplete documentation that can lead to a confusing result, missed clinical finding, or a repeat visit. 

This guide walks through what clinical staff need to know to perform an EKG correctly, document it clearly, and avoid common mistakes. This is meant for informational purposes, nothing beats practical training and certification though. 

Why EKGs Matter

An EKG is performed to record the electrical activity of the heart and to help identify any irregular heart rhythms, signs of a heart attack, structural heart issues, and the effects of certain medications. Whether performing an EKG for the first time or the thousandth time, it is important to always apply the same rigor as with any other diagnostic procedure. A lot of the medical visit depends on an accurate reading making applying accurate techniques, consistent placement, and clear documentation vitally important. 

Who Can Perform an EKG

The rules outlining the individuals that can place leads and operate an EKG machine vary state by state and on the role of the individuals such as a medical assistant, LPN, RN, EKG technician, or other qualifying role. In some states a trained unlicensed staff member can perform an EKG under the provider’s standing orders. Other states restrict the procedure to a licensed professional. It is important to always confirm your state’s requirements before performing an EKG. 

Regardless of who performs the procedure, most practices find it helpful to keep a documented internal record of who is able to perform the EKG. As always, it is important to follow strict documentation protocols such as ALCOA-C. This includes documentation of who on staff is trained and authorized to perform EKGs, what training they've completed (device-specific and general EKG technique), any provider standing orders or delegation documentation in place

Step-by-Step: Performing an EKG

Pre-Procedure Prep

• Confirm the patient's identity according to site protocol and the reason for the EKG before beginning.

• Have the patient rest for a few minutes before recording. This ensures resting heart activity since recent activity, anxiety, or movement can alter heart rate and waveform appearance.

• Ask the patient to remove jewelry or clothing that could interfere with lead placement, and ensure the skin is clean and dry at each electrode site.

Electrode Placement

Standard 12-lead placement follows consistent anatomical landmarks:

• Limb leads: right arm, left arm, right leg, left leg

• Precordial leads (V1–V6): placed at specific intercostal spaces and sternal/midclavicular reference points

Consistency of lead placement is an important aspect new staff may not consider. If a patient has their precordial leads placed slightly differently each visit a clinical change may be observed in the readings when it was really a technique artifact. Having the same trained staff repeat EKGs for patients or ensuring the leads are placed the same each time reduces this risk. 

Capturing the Reading

• Ask the patient to remain still, breathe normally, and avoid talking during acquisition.

• Capture a full tracing per your device's standard settings.

• Review the printout in real time for common artifacts, such as a recognizable inverted pattern that signals limb lead reversal, before the patient leaves. Catching this immediately avoids a repeat visit or a confusing result reaching the provider.

Documentation

• Label the tracing with patient identification, date, and time. Ensure this is complete and legible.

• Note any conditions that might affect interpretation, such as patient movement, anxiety, or equipment issues.

• File or transmit the tracing according to your practice's standard process for getting results to the ordering provider.

Common Errors to Watch For and When to Repeat

There are a few common errors that can occur during an EKG that make up a majority of EKG-related problems such as:

• Incomplete labeling — missing patient ID, date, or time on the tracing

• Lead reversal artifacts not caught before the patient leaves

• Inconsistent electrode placement across repeat visits for the same patient

• Rushed capture — acquiring the tracing before the patient has settled, leading to a noisy or unusable reading

• Skipped skin prep — poor electrode contact from lotion, sweat, or hair at the electrode site

Most of these are preventable with a short pre-procedure routine and a habit of reviewing the tracing before the patient departs. If a tracing shows clear artifact, poor lead contact, or an unexpected finding, it's usually worth a quick repeat before the patient leaves rather than sending an unclear reading to the provider. Any tracing showing signs of a potentially urgent finding should be brought to the ordering provider's attention immediately, following your practice's standard escalation process.

Training Considerations

Because EKG technique directly affects reading quality, many practices build EKG competency into new-hire onboarding and revisit it periodically, not just at initial training. A brief annual refresher or spot-check, even informal, can catch small habits that have drifted from correct technique before they start showing up in patient care. EKGs look procedurally simple, but the details are exactly where accuracy is won or lost. Staff with a clear routine and a quick pre-departure review habit will consistently produce cleaner, more reliable readings.