Test Strips

Editorial Team / Admin · Jan 5, 2014

Here is a thread with lots of references that might be useful:

https://allnurses.com/general-nursing-student/ekg-resources-student-824426.html

Having a system of analyzing each rhythm strip is important.

Look at the same things in the same order each time.

Review the cardiac electrical system and how the impulse originates and is conducted through the heart.

Blaufuss has several wonderful tutorials that, although advanced, may give you an overall picture of what is happening during each cycle. The SVT tutorial is a great visual enhancement. Blaufuss Multimedia - Heart Sounds and Cardiac Arrhythmias

I reviewed each of the rhythm strips and have provided some tips and hints below:

Briefly:

What is the rate: atrial rate? ventricular rate?

Are they the same (is there 1:1 conduction between them)? Normal rate = 60-100 beats per minute(bpm).

slower than 60=bradycardia. Faster than 100= tachycardia

Are there more P waves than QRS's? and are the P waves rapid (around 240bpm) and look like a picket fence? Likely atrial flutter. May have consistent conduction (for example every fourth P wave is conducted and a QRS follows = pulse will be regular) or variable conduction (pulse will be irregular).

Are there QRS's that are regularly irregular, and you cannot discern a clear P wave before each QRS?

May be atrial fibrillation. No P waves (baseline is jiggly but no discernible P wave before each QRS) and the ventricular rate is irregular (impulse is randomly getting through the AV node).

What is the PR interval (normal 0.12-0.20 or, 3-5 small boxes)? Is it the same for each beat?

Longer than 0.20 (200milliseconds) = 1st degree AV block.

Varying interval might be a 2nd degree AV block, Type II (Wenckebach) or Type I.

NO correlation between the P and the QRS = 3rd degree AV block or Complete Heart Block.

NO QRS after each P wave = 3rd degree block and an EMERGENCY. that heart is NOT beating!

If a rhythm strip is NSR (normal sinus rhythm) and every beat is quite regular, except ONE:

could be a

PVC (Premature Ventricular Contraction: wide and bizzare shape, no P wave before, and occurs earlier than the next anticipated beat.)

or

PAC (Premature Atrial Contraction): P wave followed by a QRS, but appears earlier than the next anticipated beat. QRS may be normal or wide (caused by aberrant conduction after the P wave).

NO discernible P waves or QRS's = asystole (absence of electrical activity)

Esme12, ASN, BSN, RN · Jan 5, 2014

Dianah has given you excellent advice and I am sure you instructor wants you to do the research/reading forward yourself icu.org is an excellent resource. click on dysrhythmias.

To understand EKG's you need to understand the cardiac cycle in correlation to the EKG complex on the strip. http://www.austincc.edu/apreview/NursingAnimations/cardiac_cycle.swf An ECG is used to measure the heart’s electrical conduction system.It picks up electrical impulses generated by the polarization and depolarization of cardiac tissue and translates into a waveform. The waveform is then used to measure the rate and regularity of heartbeats, as well as the size and position of the chambers, the presence of any damage to the heart, and the effects of drugs or devices used to regulate the heart

The cardiac cycle is divided into four separate periods, two of the periods occurring during the relaxation phase (Diastole) of the cardiac muscle, and two periods occurring during the contraction phase (Systole) of the cardiac muscle.
The first phase of the cardiac cycle is the Ventricular Filling Period (VFP) during diastole. At the start of VFP, the heart is in a polarized state and blood is moving through the atria past the heart valves and into the ventricles. As an electrical stimulus occurs from the S-A node, the myocardial cells of the atria depolarize which causes the atria to contract. This atrial contraction forces additional blood past the tricuspid and bicuspid valves, filling the ventricles. This atrial contraction is recorded on the ECG as the p wave.
The second phase of the cardiac cycle is the Isovolumetric Contraction Period (ICP) which begins systole for the cardiac cycle. The ICP is the beginning of ventricular contraction. Blood is not being ejected from the ventricles during ICP, but pressure is building in the ventricles in order to force the semilunar valves of the Aorta and pulmonary artery open. The pressure in the ventricle must exceed the pressure in the Aorta for blood to be ejected from the heart.
The third period of the cardiac cycle is the Ventricular Ejection Period (VEP) which is a continuation of the systolic phase of the cardiac cycle. During VEP, pressure within the ventricles has increased well above the pressure in the Aorta and pulmonary vein. The pressure differential forces the semilunar valves open and blood is ejected from the ventricles into the arteries. Blood will be flow past the semilunar valves until the pressure gradient in the arteries exceeds the pressure of the contracting ventricles. Upon equillibrium of the pressures between the ventricles and arteries, the semilunar valves will shut, and blood flow from the ventricles will cease.
The electrical recording for both ICP and VEP are illustrated on the ECG as the QRS complex. The final period of the cardiac cycle is the Isovolumetric Relaxation Period (IRP) and occurs during diastole. The ICP is characterized as the resting phase of the cardiac cycle when the ventricles are repolarizing and all valves (bicuspid, tricuspid, and semilunar) are closed. The electrical recording for IRP is illustrated on the ECG as the t wave.

cardiac cycle

Esme12, ASN, BSN, RN · Jan 5, 2014

Attached is a document that talks about how to read and analyze a EKG strip.

Normal Intervals:
PR .12 -.20 seconds
QRS .06 - .10 seconds
Inherent Rates
SA node 60 - 100
AV junction 40 - 60
Purkinje system 20 - 40I.

Each abnormal rhythm has it's own set of requirements.

http://sitemaker.umich.edu/ecgtutorial/abnormal_rhythm

Premature atrial contractions. These are early extra beats that originate in the atria (upper chambers of the heart). They are harmless and generally do not require treatment.
Premature ventricular contractions(PVCs). These are among the most common arrhythmias and occur in people with or without heart disease. This is the skipped heartbeat we all occasionally experience. In some people, it can be related to stress, too much caffeine or nicotine, or too much exercise. But sometimes, PVCs can be caused by heart disease or electrolyte imbalance. People who have a lot of PVCs, and/or symptoms associated with them, should be evaluated by a heart doctor. However, in most people, PVCs are usually harmless and rarely need treatment.
Atrial fibrillation. Atrial fibrillation is a very common irregular heart rhythm that causes the atria, the upper chambers of the heart, to contract abnormally.
Atrial flutter. This is an arrhythmia caused by one or more rapid circuits in the atrium. Atrial flutter is usually more organized and regular than atrial fibrillation. This arrhythmia occurs most often in people with heart disease and in the first week after heart surgery. It often converts to atrial fibrillation.
Paroxysmal supraventricular tachycardia (PSVT). A rapid heart rate, usually with a regular rhythm, originating from above the ventricles. PSVT begins and ends suddenly. There are two main types: accessory path tachycardias and AV nodal reentrant tachycardias (see below).
Accessory pathway tachycardias. A rapid heart rate due to an extra abnormal pathway or connection between the atria and the ventricles. The impulses travel through the extra pathways as well as through the usual route. This allows the impulses to travel around the heart very quickly, causing the heart to beat unusually fast.
AV nodal reentrant tachycardia. A rapid heart rate due to more than one pathway through the AV node. It can cause heart palpitations, fainting, or heart failure. In some cases, it can be terminated using simple maneuvers, such as breathing in and bearing down. Some drugs can also stop this heart rhythm.
Ventricular tachycardia (V-tach). A rapid heart rhythm originating from the lower chambers (or ventricles) of the heart. The rapid rate prevents the heart from filling adequately with blood. This can be a serious arrhythmia, especially in people with heart disease, and may be associated with more symptoms.
Ventricular fibrillation. An erratic, disorganized firing of impulses from the ventricles. The ventricles quiver and are unable to contract or pump blood to the body. This is a medical emergency that must be treated with cardiopulmonary resuscitation (CPR) and defibrillation as soon as possible.
Long QT syndrome. The QT interval is the area on the electrocardiogram that represents the time it takes for the heart muscle to contract and then recover, or for the electrical impulse to fire impulses and then recharge. When the QT interval is longer than normal, it increases the risk of a life-threatening form of ventricular tachycardia. Long QT syndrome is an inherited condition that can cause sudden death in young people. It can be treated with antiarrhythmic drugs, pacemaker, electrical cardioversion, defibrillation, implanted cardioverter/defibrillator, or ablation therapy.
Bradyarrhythmias. These are slow heart rhythms, which may arise from disease in the heart's electrical conduction system. Examples include sinus node dysfunction and heart block.
Sinus node dysfunction. A slow heart rhythm due to an abnormal sinus node. Significant sinus node dysfunction that causes symptoms is treated with a pacemaker.
Heart block. A delay or complete block of the electrical impulse as it travels from the sinus node to the ventricles. The heart may beat irregularly and, often, more slowly. If serious, heart block is treated with a pacemaker.

cardiac cycle.docx

Esme12, ASN, BSN, RN · Jan 5, 2014

cardiac rhythms

cardiac rhythms.docx

Esme12, ASN, BSN, RN · Jan 5, 2014

Now looking at your strips. Electrocardiogram (ECG, EKG) library

The first one you didn't understand. Go through your criteria. Is there a P wave for every QRS that "looks normal". Are they regular? Look at the irregular beat. Is it early? Can you see a P wave? Is the QRS on this beat like the other QRS?

This beat is early. It is unlike the other QRS beats and is wide and bizarre. A premature with a wide QRS originates in the ventricle so this is a PVC. Premature ventricular contraction.

The next look at the criteria. DO you have P waves? Do you have a QRS for every P wave? If you have P waves and no QRS the ventricles are not working. What rhythm do you have?

I) You have P waves and you have QRS complexes but they are beating independent of each other as if they are dissociated from each other. What is this rhythm?

J) You have P waves and you have 2 QRS complexes. 2 of the P waves conduct through to the ventricles 4 of them are blocked. What rhythm is this?

K) You once again have discernible P waves and describable QRS complexes but they don't seem to be talking to each other. Remember to look at heart rate when deciding your rhythms.

Inherent Rates

SA node 60 - 100

AV junction 40 - 60

Purkinje system 20 - 40.

L) You have P waves for every QRS except one is dropped. Your PR interval seems to be increasing in length before one is dropped/BLOCKED. What is this rhythm?

M) This too has a cyclical increase of the PR interval when a beat is dropped/BLOCKED. Your P waves "march through" on time like the one above.

N) You have P waves that come at regular intervals but only every third is conducted the rest are BLOCKED

O) and P) are yours.

Q) You have slow QRS complexes with a P wave after the QRS.

Now what are these rhythms

Sometimes patients have pacemakers. That electrical activity is seen on the EKG. icufaq's.org has a section on pacemakers and this is another great site....Pacemaker Rhythms - Life in the Fast Lane ECG Library

Personally...even experienced nurses have trouble with pacers and I think it isn't fair your instructor expects interpretation without guidance. I don't usually give answers but this is a ton of information sent ahead of lecture as long as you promise to look at the links.

There are different types of pacers ventricular pacers: example S (which pace only the ventricles), atrial pacers: example T (which pace the atria), and AV sequential pacers: example U (which pace both).

Sometimes they malfunction.....they fail to capture: example V and you have pacer spikes without capture. Sometimes they fail to sense the patients rhythm: example W

I hope this helps

Editorial Team / Admin · Jan 6, 2014

Personally...even experienced nurses have trouble with pacers and I think it isn't fair your instructor expects interpretation without guidance. I don't usually give answers but this is a ton of information sent ahead of lecture as long as you promise to look at the links.
There are different types of pacers ventricular pacers: example S (which pace only the ventricles), atrial pacers: example T (which pace the atria), and AV sequential pacers: example U (which pace both).
Sometimes they malfunction.....they fail to capture: example V and you have pacer spikes without capture. Sometimes they fail to sense the patients rhythm: example W
I hope this helps

Esme, I totally agree with you.

OP did say she was trying to get a jump on this and start early.

It's a steep learning curve! :)

At least, OP, you can get the basics down: what a NSR looks like and what the criteria are for determining a NSR.

It is exciting to be able to recognize the rhythms!

You WILL get there!

Good luck!

WPARRISH24 · Jan 7, 2014

Thank you very much. All the information is helpful. I have looked at the sites and I will continue to do more practice problems.