First of all, I want any new nurses out there reading this to know that learning how to do this is tough. It takes some time to understand how to interpret 5-Lead ECGs, and specifically what you need to know for your unit. Naturally, a cardiac acute care nurse will deal with this much more than someone who works inpatient rehab, orthopedics, or on another non-cardiac unit.
Let’s dive into what acute care nurses need to know about 5-Lead EKG/ECG Interpretation so you can look like a pro!
What we’ll cover:
(You can skip to the section for each type by clicking on the below links)
- ECG vs EKG
- 12-Lead ECG vs. 5-Lead ECG
- Normal ECG Levels
- 12-Lead Placement
- 12-Lead Interpretation
- 5-lead ECG Placement
- 5 lead ECG Interpretation
- Common Rhythms You’ll See
ECG vs EKG – what’s the difference
Basically, an EKG is the exact same thing as an ECG. You’ll hear it called both and they both mean electrocardiogram.
You may be wondering where that K comes from in EKG. Well, it originates from the German spelling of electrocardiogram (elektro-kardiographie). It’s a basic difference in spelling and language (like color vs. colour) and doesn’t not change the meaning of the abbreviation.
You can confidently use EKG and ECG interchangeably. You may run across people who are adamant one way or the other, but it’s nothing to get your telemetry leads all twisted up 🙂
12-Lead ECG vs. 5-Lead ECG
Before we dive into interpretation – let’s clarify one important thing. Most cardiac patients are on a telemetry monitor. This means they’ve got 5 leads (wires that are connected to things that connect to adhesive pads) attached to their chest, and you can see their rhythm at all times at the nurse’s station and/or the bedside monitor.
Bedside nurses are responsible for monitoring these rhythms, watching for changes and notifying the physician regarding changes and concerns. A 5-lead provides a lot of information, but if something concerning is noted, a 12-lead ECG is ordered to provide even more information.
Think of each lead like a camera, taking a snapshot of the heart’s electrical activity. Twelve cameras provide substantially more information than five.
You may ask yourself: why don’t we just continuously monitor with 12 leads?
That is a very good question! Well, that’s a lot of leads to constantly have on someone to get tangled up in, it’s incredibly expensive, and not medically necessary. The 5-lead provides plenty of information for routine monitoring.
So, if your patient is having new chest pain, a new cardiac rhythm, was started on a specific cardiac medication, had a procedure, is decompensating, or a plethora of other possibilities, the physician may order a 12-lead ECG. Depending on where you work, the bedside nurse may complete the 12-lead, or an ECG tech (a person whose job it is to obtain ECGs on people all day, traveling from room to room) may come to complete the procedure. It’s pretty quick, and it honestly takes longer to attach all 12 leads than to get the reading. ECG techs are pretty awesome at these because they do them all day and can get them done very quickly.
Normal 5 Lead ECG Levels / What is a normal ECG reading
Regardless of where the patient is, many hospitals require patients on a heart monitor to have a 5-lead strip documented every shift and with any rhythm changes or significant patient events (like a code). But, how this is done depends on the unit.
If you’re working on a cardiac floor, typically a monitor tech in a different location will print and interpret your strips for you, and you simply verify them in your documentation and make corrections as needed. A monitor tech is someone whose job is to watch many 5-lead telemetry strips at once, document, and notify the nurse as changes occur. This is necessary because nurses on the floor are caring for many more patients and their patients are not on a bedside monitor for them to be able to visualize immediately. Typically a monitor is at the nurse’s station, but not in each patient’s room.
If you’re working in a step-down or intensive care environment, you most likely print and interpret your own, then document appropriately. Monitors are typically in the room and at the nurse’s station.
The ED environment is a bit different. Patients are coming in, needing to get diagnosed quickly. Therefore, as an ED nurse, you’ll be dealing with more 12-lead ECGs on a regular basis. Not all patients will necessarily be hooked up to a bedside monitor, but if they came in with cardiac concerns, they most likely will be. Twelve-leads are obtained and given to the provider, and 5-lead strips are printed and scanned into a chart but are not necessarily interpreted by the nurse. (This may differ from facility to facility.)
When interpreting an ECG, you identify if a wave is present, or not present. If a wave is not present, it will help you interpret the rhythm. For example, in atrial fibrillation, the P wave is missing (see the afib module for an explanation of why). Some measurements are from the beginning of one wave to the end of another.
You have the PR interval, QRS complex, QT interval, and the ST segment. When reading an ECG you need to interpret each wave, measure distance using the graph paper it is laid on or use calipers, as well as determine its regularity and rate.
This rhythm originates from the Sinoatrial Node (SA Node) which is called the heart’s natural pacemaker. It has all the waves of an ECG, is a rate between 60-100 BPM, and is considered a perfect ECG. To identify normal sinus rhythm, start by counting the rate and identify if it is regularly happening. Next, look at the waves.
Here are a few questions for you to answer to help identify if the 5 Lead ECG is normal sinus rhythm or not.
- Is there a P wave?
- Is the P wave happening regularly?
- Does every P wave have a QRS complex following it?
- Do all the P waves look the same?
- Is the PR interval between 0.12-0.2 seconds?
- Does the interval time stay the same or vary?
- Is the QRS interval between 0.08-0.1 seconds?
- Are they the same height?
- Is the R wave to R wave consistent?
- Is there a T wave?
- Does it follow a QRS complex?
- How tall is the wave?
- Is the interval less than 0.44 seconds?
- Is the line flat and in line with the isoelectric line?
If the answer to all of these questions is ‘yes’ and the rate is between 60-100 BPM, then the ECG is called normal sinus rhythm.
Alright, so how do you actually get a 12-lead ECG if it’s been ordered? Again, you may not need to do this at your facility. If you’re new to your role and know you won’t routinely be responsible for this, skip this section. It is unnecessary detail for you right now and there’s no need to spend cognitive energy on something you’ll rarely do when there are so many other things you could focus on.
The down and dirty method to know where to put these leads is called the ‘Angle of Louis’ method. I like it; easy to remember and as simple as it gets.
We’ve got 10 wires we need to attach to the body. Six of these wires will be attached pretty close to one another, while two will be on the legs and two will be on the upper chest/arm region. They are called V1, V2, V3, V4, V5, V6, RA, LA, RL, and LL.
Let’s begin with placing V1-V6.
For V1; locate the sternal notch (AKA the Angle of Louis) at the second rib and feel down the sternal border, counting as you go. When you get to the fourth intercostal space, stop and place V1 just to the right of the sternal boarder. V2 goes on the left side. Easy peasy!
We’ve got to do V4 next. Go down one intercostal space to the fifth intercostal place and hold your finger there. Now, look at your patient’s clavicle and imagine you are drawing a line from the midpoint of their left clavicle to their 5th intercostal space. Place V4 there. Then, put V3 directly in between V2 and V4.
Now, KEEP YOUR FINGERS IN THAT 5TH INTERCOSTAL PLACE PLEASE AND THANK YOU.
Imagine a line going straight down from their armpit/axillary reason to that 5th intercostal space. Place V6 there.
Place V5 right in between V4 and V6.
The right arm lead (RA, white) is placed on the right shoulder, while the left arm lead (LA, black) is placed on the left shoulder.
The right leg (RL, green) is placed on the upper and inner right leg, while the left leg lead (LL, red), is placed on the left upper and inner shoulder.
Please note, you can also put these arm/leg leads on the wrists and ankles as well. It does not matter which you choose, but as long as you’re consistent with upper and lower limbs and keeping them symmetrical.
Therefore, if you do wrists then you MUST do ankles.
If you do shoulders you MUST do upper/inner thighs.
Actually getting the ECG reading depends on the device you are using, so we won’t get into that. Typically, it’s a matter of pressing one button.
12-Lead ECG Interpretation – is it necessary for new nurses?
Ok, now that you’ve got the leads attached and have hit “record” an obtained the ECG – what do you do with it?
Twelve-lead ECGs typically come with an interpretation at the top that the machine automatically generates. This is not always correct and you cannot rely on it to accurately interpret the rhythm.
If you want to get into the deep details of reading 12-leads, there are many courses available for this. Your hospital may offer specific ones (I’d check into that first before buying anything). However, just dipping your toes into cardiac for the first time, let’s stick to the basics before interpreting 12-lead ECGs.
Speaking as a bedside nurse, the priority is to learn how to interpret your 5-lead telemetry strips as well as knowing when something concerning is going on with a 12-lead. However, this can get INCREDIBLY detailed. When you are at this stage in your career of just learning how to keep your head above water in cardiac patient care, save learning the origins of myocardial infarctions and changes in specific leads and whatnot for when you are ready. Focus on recognizing rhythm changes, assessment skills, patient care, meds, and chatting with physicians about what to do first. Then dive into the more complicated information.
Yes, it is important to notice things like ST-elevation on an ECG – especially in the emergency department. We’ll chat about this shortly, as it indicates an emergency requiring STAT intervention. But there’s a difference between identifying that major issue and being able to closely evaluate a very complex EKG. Expecting a newbie nurse to not only do that, but know appropriate interventions is unrealistic in my professional opinion.
Please don’t feel like an incompetent nurse if you can’t quickly interpret a 12-lead someone shoves in your face two weeks into orientation. The first time I really got my brain around getting deeper into 12-leads was when I was studying for my national critical care certification (CCRN) in 2015, five years into my career.
You may run into nurses who think every nurse should know how to do this at the beginning. However, learning the intricacies of a 12-lead before you’re confident in your basic cardiac patient care is like learning how to dunk before learning how to dribble.
5-lead ECG Placement
Ok, let’s say you are on your cardiac unit and you’re admitting a patient who now needs continuous cardiac monitoring. Other names for this include placing a patient “on the monitor,” “monitored,” or on telemetry. Knowing 5 lead ECG placement is critical to a fast and efficient admission.
How do you place them on the monitor exactly?
You’ll have to obtain a telemetry box, leads, and pads. You’ll first place the adhesive pads on their skin in the below locations. Then, you’ll attach the appropriate leads. Next, you most likely need to call whichever unit in your hospital continuously monitors these (if that’s how your organization does things!) to confirm the patient, their information, and that they can see the tracing on their end of things.
If your patient has a pacemaker or skin issues, you may need to place your pads in alternative locations that we’re not going to dive into here.
Below is the anatomical location of each lead:
- White is on the right side, just below the clavicle (midway)
- Black is on the left side just below the clavicle
- Brown is in the 4th intercoastal space, just to the right of the sternum
- Green is on the right on the lower edge of the rib cage
- Red is on the left of the lower edge of the rib cage
A little rhyme I use to remember 5-Lead ECG placement is:
- Smoke over fire – (black over red)
- Clouds over grass – (white over green)
- Chocolate on the stomach- (but you must remember that it’s not on the actual stomach but on the right sternal boarder of 4th intercoastal space)
That may help you remember this in the moment as you’re attaching leads to a patient’s chest.
There you have it, 5 lead ECG placement simplified.
5 lead ECG Interpretation
As the nurse caring for the cardiac patient, you will be responsible for monitoring their telemetry for changes. This typically includes printing off a 6-second strip once per shift (and with any other rhythm changes) and interpreting it in the patient’s medical chart. If you’re on a cardiac floor, this may be done by someone else and you are sent the strip to confirm their interpretation and add it to their chart.
If you’re in ICU, it’s typically a little different. It’s most likely attached to a monitor at the bedside and you see their waveform on a screen next to the bed. You would be required to print and interpret yourself, then place into the chart.
At first, it’ll take you a bit of time to get into the habit of interpreting these. Think of it like a golf swing or assessment: do it the same way every time.
First, make sure you’ve got a good strip that doesn’t have a bunch of artifact (lines all over the place, not really a clear reading… almost like when your phone is buffering and trying to get back on track). Wait to print to until you’ve got a clear reading, and if you were sent a strip that is full of artifact – request a new one.
First, I always check to make sure it’s regular. I do that by making sure the space between each R wave is equal. Some people call this, “making sure the R’s march out”. You can use a set of calipers or even a small piece of paper. Mark the space between two R waves and see if the others compare. If they all match up, it’s regular.
Then, see if there is a P wave before each QRS complex. See if they all look the same.
Then, measure your PR interval. If it’s between 0.12-0.20, then we’re another step closer to a normal rhythm.
Next, measure your QRS complex. Is it 0.08.0.1? Yahoo!
Is there a T wave? There may not be, so don’t fret if you don’t see one. If there is, is it normal or upside down/inverted?
And, do the S wave and the T wave sort of go together to create an elevation (if so, that’s bad news bears!)
You can also go through that list up at the top of normal sinus rhythm as well. If the answer to all of the above is yes, then you can chart NSR or normal sinus rhythm. That means the SA (sinoatrial node) node is sending electrical signals and they’re getting to all of the appropriate locations and the heart beats accordingly. (Normal sinus rhythm).
Now that we’ve gone over normal, let’s go into some other rhythms you may see!
Common Rhythms You’ll See
Sinus Tachycardia (ST)
This rhythm has all the waves and is the proper measurements but is occurring consistently at a rate faster than 100 BPM. Sometimes, if the rate is really fast, it is difficult to read all the waves. There is an option on 12 lead ECG machines and some cardiac monitors that will allow you to slow the rhythm down and stretch it out. This allows you to see all the waves if they are present.
The signals are still being sent from the SA node, but the SA node is depolarizing faster than normal. The most important thing to understand about ST is that the heart’s cardiac output is decreased and so is coronary artery perfusion.
Often the patient is dehydrated and the first line of treatment will be administering IV fluids. If the patient does not respond to IV fluids then further investigation is needed. For example, is the patient febrile? Getting the temperature-controlled will also bring the heart rate back to a normal rate. The treatment for sinus tachycardia is to eliminate the factor that is causing the heart to beat so fast.
Below is a list of things that can cause ST in patients:
- Hypovolemia (dehydration)
This rhythm also has all the waves but is slower than 60 BPM. This number needs to carefully be considered as people have resting heart rates at 50 BPM that are completely normal, especially if they are athletes. (The heart is a muscle, so if someone regularly works out their muscle with cardio exercise, it will beat more efficiently.)
The signals from the SA node are depolarizing at a much slower rate than normal in this rhythm. It is generally caused by stimulation of the parasympathetic nervous system (vagal). If the patient is experiencing sinus bradycardia, the time their heart spends in diastole in greatly increased and the cardiac output is decreased.
The most important thing to assess for a patient in sinus bradycardia is whether they are symptomatic or not.
- Altered Mental Status
- Shortness of Breath/Pulmonary Edema
If the patient is symptomatic, this is an urgent situation. You may need to give the patient some oxygen and prepare for potential transcutaneous pacing by pulling the crash cart over and hooking the patient up to the electrode pads.
The first line treatment depends on if the patient has a heart transplant or not. If they do not have a heart transplant and it is their original heart, prepare for the doctor to order 0.5 mg of Atropine. Atropine can be repeated every 3-5 minutes and has a maximum dose of 3 mg (6 doses of 0.5 mg). If the patient has had a heart transplant, the first-line treatment is isoproterenol (Isuprel).
If the first line doesn’t work, the second line is transcutaneous pacing (more about this in the ACLS module). If transcutaneous pacing is not available, the doctor might order an IV drip of epinephrine or dopamine.
If the patient doesn’t have any symptoms (asymptomatic), then the physician may just want to monitor and not intervene. Generally speaking, asymptomatic sinus bradycardia is not concerning. Think about it: if they’re not having any symptoms (dizziness, hypotension, weakness, AMS, etc), that means they probably have adequate cardiac output and therefore don’t require any intervention.
Tip – if your patient has a resting heart rate that’s pretty low and you’ve notified the physician, make sure you ask them when they’d want to be notified. This is especially helpful on the nursing floor when you have patients whose heart rates will dip down into the ’30s when sleeping. If the physician isn’t worried about it, just get an order for when they’d like to be notified again. Chances are, it’ll be if they become symptomatic. This will save you and your next shift quite a few unnecessary pages.
Premature Ventricular Contractions (PVCs)
Premature ventricular contractions (PVCs) occur when the ventricles receive an impulse prematurely, having them contract before they are supposed to, interrupting the cardiac electrical cycle. They can be harmless and common, however, they can also spark electrical chaos within the heart that can be harmful.
The more frequently PVCs occur, the more concerning they become. If the patient has two in a row, this is called a couplet.
A PVC may also occur every second beat (called bigeminy), every third (called trigeminy) or every fourth beat (called quadrigeminy).
If a patient has three or more PVCs in a row it is considered Ventricular Tachycardia and this is life-threatening.
To measure a PVC on an 5-Lead ECG: The QRS complex is wider than 0.1 seconds and the R to R measurement is not regular from the other R to R measurements (the PVC comes earlier than it is supposed to).
Premature ventricular contractions will need to be monitored for frequency and treatment isn’t generally needed until the PVC occurs too frequently turning into Ventricular Tachycardia.
Tip – if you’re working at the bedside and see that PVCs are increasing in frequency, that’s a notify the provider kind of situation. Check their electrolytes like potassium and magnesium to see if they’re low (that will be one of the first questions they ask you!) and if they take any antidysrhythmics normally.
Atrial Fibrillation (A-fib) and Afib with Rapid Ventricular Response (RVR)
Atrial Fibrillation occurs because the signals in the atria are chaotic, causing the atria to quiver. A clear contraction of the atria does not occur, thus the P wave will be absent. In place of the P wave, there will be erratic scribbles. The ventricles receive confusing signals for when to contract so they contract irregularly.
The biggest problem with atrial fibrillation is the blood pooling in the atria causing blood clots to form and then sent into the bloodstream throughout the body.
If the rate is a controlled rate and the patient is asymptomatic, patients can live with afib, taking an anticoagulant to prevent blood clots from forming. If the patient is symptomatic and/or the rate is uncontrolled they may need treatment.
An uncontrolled afib rate is anything above 100 BPM and is called afib with RVR (atrial fibrillation with rapid ventricular response). These patients will likely be symptomatic and may feel like their heart is racing like they might pass out, dizziness and/or shortness of breath. Afib w/RVR is also called in the clinical setting SVT w/ RVR or just SVT.
Atrial Flutter (A-flutter)
This arrhythmia is easily recognized because of the sawtooth pattern that appears on the 5-Lead and 12-Lead ECG. In Aflutter, the conduction path from the sinoatrial (SA) node to the atrioventricular node (AV node) is spiral in nature and no longer the smooth direct pathway. The impulse still reaches the AV node causing the ventricles to contract and the QRS complex to appear at a regular interval.
Aflutter and Afib are very similar. Aflutter can turn into Afib. The signs and symptoms, as well as the treatment for Aflutter, are the same as the treatment for Afib.
If you want to learn more about 5-Lead ECGs and cardiac patient care:
Speaking as an experienced cardiac nurse who was once new, I know all the struggles that come with starting on a cardiac unit.
I know all of the questions, concerns, and areas of uneasiness. Learn how to receive a patient from the cath lab with ease, confidently address the patient who flipped into atrial fibrillation with a rapid ventricular response, and care for chest tubes like a pro.
This course is for newbies to cardiac to help you build a focused foundational cardiac knowledge – concise information you need to be successful at the bedside, and not feel like you’re drowning. And of course, learn how to interpret a 5-Lead ECG like a champ.
This content is applicable to adult patients in the emergency department, cardiac intensive care, stepdown, and cardiac nursing floor.