5-Lead ECG Interpretation for Nurses

Updated: September 2026

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Getting your patient on telemetry is one thing. Looking at the tracing and knowing what to check next is another.

A 5-lead ECG uses five electrodes and their connecting wires to monitor the heart’s electrical activity continuously. For bedside nurses, the essentials are correct placement, a readable tracing, a consistent interpretation process, and recognizing when your patient needs immediate assessment or a 12-lead ECG.

Let’s walk through the setup first, then work through a rhythm strip.

5-Lead ECG Placement and Colors

The table below describes common adult torso placement using AHA wire colors, often used in the United States. Right and left always mean the patient’s right and left.

Wire label	AHA color	Common monitoring location
RA	White	Upper right torso, below the right clavicle
LA	Black	Upper left torso, below the left clavicle
RL	Green	Lower right torso
LL	Red	Lower left torso
V	Brown	Selected chest position; if monitoring V1, fourth intercostal space at the right sternal border

Need help getting your patient connected? Follow our telemetry lead placement guide, then return here to work through the rhythm interpretation steps.

(Note: If patients are in ICU, the emergency department, or stepdown, they likely have one that looks a little different. I explain that more in my mini course, ➡️ Telemetry Basics-Brush Up ⬅️.)

How to Interpret a 5-Lead ECG Rhythm Strip

Use the same sequence each time. That gives you something concrete to do when the tracing looks unfamiliar.

1. Assess the patient and check the signal

How does the patient look and feel? Assess responsiveness, breathing, pulse, blood pressure, and symptoms as appropriate. If the patient is unstable, activate your emergency response process immediately while providing care within your training and protocol. For a stable patient, check electrode contact, connections, and the selected lead. Compare another available lead when the tracing is unclear.

2. Determine the rate and regularity

Check the heart rate and the spacing between QRS complexes. Are the R-to-R intervals consistent, irregular in a repeating pattern, or irregular without a pattern? Confirm the recording speed before measuring. At the standard speed of 25 mm/second, one small box represents 0.04 seconds. On a verified six-second strip, counting QRS complexes and multiplying by 10 gives an approximate ventricular rate.

3. Look for P waves

Is there a P wave before each QRS? Does every P wave conduct to a QRS? Do the P waves have a consistent appearance in the same lead? If you cannot identify atrial activity, avoid jumping straight to a rhythm label. Check signal quality and another available lead.

4. Measure the PR interval and QRS duration

Measure the PR interval from the beginning of the P wave to the beginning of the QRS. A typical adult PR interval is 0.12–0.20 seconds. Measure QRS duration from the beginning to the end of the complex. A QRS under 0.12 seconds is generally considered narrow.

A wide QRS requires further interpretation; it does not identify a single rhythm by itself. You can use the individual boxes to measure, or you can use calipers for it to be more precise.

5. Review ST-T changes and compare with baseline

Look for new changes and relate them to the patient’s symptoms. T-wave direction depends on the lead, so an inverted T wave is not automatically abnormal in every view. Concerning ST changes require further assessment; a telemetry tracing alone cannot establish or exclude a heart attack.

Want something handy while you practice?

You don’t have to memorize all of this in one sitting. Grab my free ECG Interpretation Cheat Sheet to keep nearby as you work through rhythm strips. Repetition is how this starts to click! ⬇️

What supports normal sinus rhythm?

Look for:

• A rate of 60–100 beats/minute
• A regular rhythm, consistent sinus P waves before each QRS
• A QRS after each P wave, and a consistent PR interval within the expected range

In an uncomplicated normal tracing, the QRS is narrow. Sinus rhythm can coexist with other ECG abnormalities, so keep describing what you see rather than treating the label as proof that everything is normal.

Common Rhythms Nurses Encounter

Sinus tachycardia

Sinus tachycardia is a sinus rhythm above 100 beats/minute. Consider the situation: activity, pain, fever, hypovolemia, and other underlying problems can increase the rate. Treatment addresses the cause. Fluids are appropriate for some patients, not an automatic response to every fast heart rate. New or persistent tachycardia needs assessment in context.

Sinus bradycardia

A sinus rate below 60 beats/minute may be normal for some patients. Compare with baseline and assess perfusion and symptoms. Hypotension, altered mental status, ischemic discomfort, or acute heart failure associated with bradycardia requires urgent escalation. Use the current algorithm and your facility’s protocol for treatment rather than an older memorized medication dose.

Premature ventricular contractions

PVCs are early beats originating in the ventricles. Assess whether they are new, increasing, associated with symptoms, or occurring in runs. Review relevant medications and available electrolyte results as part of the clinical assessment. Do not wait for a sustained arrhythmia before reporting a concerning change.

Atrial fibrillation and atrial flutter

Atrial fibrillation commonly produces an irregularly irregular ventricular rhythm without consistent discrete P waves. Atrial flutter may show organized flutter waves; the ventricular rhythm can be regular or irregular depending on conduction.

With either rhythm, assess the patient’s stability and whether the finding is new. Treatment may involve rate control, rhythm control, and stroke prevention based on the patient’s circumstances. Use the specific rhythm name when communicating, and escalate immediately if the patient is unstable.

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5-Lead vs. 12-Lead ECG

Here’s where the terminology gets a little confusing. We often call the wires “leads” at the bedside, but technically, an electrode is the sticky pad on the patient’s skin, and a lead is a view of the heart’s electrical activity.

So, a 12-lead ECG actually uses 10 electrodes to give us 12 different views. Yep, 10 stickers, 12 views! With a five-wire telemetry setup, you have five electrodes, but the views you can display depend on your monitor. The number of wires doesn’t tell you how many diagnostic views you’re getting.

Think of telemetry as a way to keep an eye on the patient’s rhythm throughout your shift. A 12-lead gives you a more detailed look from multiple angles, usually in a quick recording.

If your patient develops new chest discomfort, a concerning rhythm change, or other signs of possible ischemia, they may need a prompt 12-lead and further evaluation according to your unit’s protocol. A rhythm that looks reassuring on the monitor doesn’t rule out acute coronary syndrome. If your patient is telling you something feels wrong, that still needs your attention.

What to Communicate When the Rhythm Changes

Have the rhythm strip available and report the change clearly:

• The patient’s current symptoms and vital signs.
• What changed from baseline and when it started.
• The rate, regularity, and rhythm findings you identified.
• Relevant medications, recent interventions, and available laboratory results.
• What you have assessed or done and how the patient responded.

For an unstable patient, call for help immediately. You do not need a perfect rhythm interpretation before escalating a clinical emergency. Documentation responsibilities vary by hospital. Know who reviews strips, how often they are recorded, how central monitoring communicates urgent changes, and what you are expected to verify yourself.

Here’s what that might sound like when you call the provider about a patient who is currently stable:

“Hi, this is Kati, the nurse caring for Mr. Jones in room 412. About 10 minutes ago, his rhythm changed from sinus rhythm in the 80s to an irregular rhythm at 120–140. I’m not seeing consistent P waves, and I’m concerned this could be new atrial fibrillation.

He says his heart feels like it’s racing, but he denies chest pain, shortness of breath, or dizziness. He’s alert, his blood pressure is 118/72, and his oxygen saturation is 96% on room air.

I checked his electrodes and connections, and the rhythm is still present in another lead. I have the strip available. His morning potassium was 3.4 and magnesium was 1.7. He received his scheduled metoprolol at 0900, and the rate has stayed elevated while he’s resting.

Can you come evaluate him? Would you like a 12-lead ECG and repeat electrolytes?”

Notice that you’re telling the provider what changed, how the patient is tolerating it, and what you’ve already checked. You’re also making a clear request. You don’t have to sound fancy or have the rhythm completely figured out to make a useful call.

And if that same patient becomes hypotensive, develops chest pain, or has a change in mental status? Call for immediate help according to your unit’s emergency response process. Don’t delay while you gather every lab result or practice the perfect report.

Frequently Asked Questions About 5-Lead EKG Interpretation

Are ECG and EKG the same thing?

Yes. Both abbreviations refer to an electrocardiogram.

Where does the brown wire go?

On an AHA five-wire cable, brown identifies the chest wire. If V1 is selected, the electrode belongs at the fourth intercostal space along the right sternal border. Use the chest position specified for the monitoring purpose and device configuration.

Does a 5-lead monitor replace a 12-lead ECG?

No. Continuous rhythm monitoring and a diagnostic 12-lead answer different clinical questions. Obtain further assessment when symptoms or findings warrant it.

Can I use this placement guide for a Holter monitor?

Do not assume the configurations are identical. Follow the instructions for that specific ambulatory monitor; five-electrode Holter arrangements can differ from bedside telemetry.

Build Your Rhythm Interpretation Skills

Reading a rhythm strip becomes more manageable when you practice the same process repeatedly. If you want guided teaching on rhythm recognition and nursing responses, explore ECG Rhythm Master.

References

1. American Heart Association. Top Things to Know: Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings. October 3, 2017. View source.
2. Merck Manual Professional Edition. Electrocardiography. View source.
3. American Heart Association. Tachycardia: Fast Heart Rate. View source.
4. American Heart Association. Adult Bradycardia With a Pulse Algorithm. 2025. View PDF.
5. American Heart Association. Premature Contractions—PACs and PVCs. View source.
6. American Heart Association. Top Things to Know: AF Occurring During Acute Hospitalization. March 13, 2023. Prepared by Janice Y. Chyou, MD, FAHA. View source.
7. American Heart Association. Other Heart Rhythm Disorders. View source.
8. GE HealthCare. Diagnostic ECG Lead Placement. Document DOC0259509, revision 2. View PDF.
9. Philips Medical Systems. HeartStart XL M4735A Defibrillator/Monitor: Instructions for Use. Edition 7, April 2006. Chapter 4: Monitoring the ECG. View PDF.