Quiz 3 - EKG Quiz Flashcards
What do each of these means:
- P Wave:
- PR Interval:
- PR Segment:
- QRS Complex:
- ST Segment:
- ST Interval:
- T Wave:
- TP Interval:
- U Wave:
- P Wave: Atrial depolarization (or contraction)
- PR Interval: From start of P wave to R (or right before QRS. So it includes atrial depolarization and AV node delay).
- PR Segment: JUST the portion of the AV node delay / atrial kick. (S = S … Segment = Small)
- QRS Complex: Ventricle contraction or depolarization (and atrial relaxation or repolarization … can’t see because its behind QRS complex)
- ST Segment: Final part of ventricles contracting to when ventricles start repolarizing / relaxing. From end of S to start of T. (S = S … Segment = Small). Where you’d see elevation (=infarction), or depression (=ischemia).
- ST Interval: From S to end of T, so includes end of ventricular contraction and ventricular repolarization.
- T Wave: Ventricle repolarization
- TP Interval: Space of time between a cardiac cycle when the ventricles are relaxing and filling.
- U Wave: Repolarization of pukinjie fibers (probably won’t see this ever).
Depolarization means:
Repolarization means:
Clever way to remember:
Contracting. After a cell has established a resting potential, that cell has the capacity to undergo depolarization. … As the sodium ions rush back into the cell, they add POSITIVE charge to the cell interior, and change the membrane potential from negative to positive.
Relaxing. Refers to the change in membrane potential that returns it to a NEGATIVE value just after the depolarization phase of an action potential has changed the membrane potential to a positive value.
Re = RElax De = detonate / contract
Where does P wave originate from (gets its conduction from)?
SA Node
What is the AV Node delay:
Why is it important:
What is another name for this:
Where would this show up on an EKG?
The action potential is initiated at the SA node and spreads as a wave through the atrial muscle. When the impulse reaches the AV node there is a slight delay before the AV node fires (which will start conductivity / depolarization for the ventricles). This gives the atria time to squeeze extra blood into the ventricles before they fire.
This delay in the cardiac cycle is extremely important: It ensures that the atria have ejected their blood into the ventricles first before the ventricles contract. IT increases EDV.
Atrial kick: the priming force contributed by atrial contraction immediately before ventricular systole that acts to increase the efficiency of ventricular ejection due to acutely increased preload.
After the P Wave, there is a flat line before the QRS complex called the PR segment, and this would be the AV node delay / “atrial kick.”
What segment indicates atrial relaxation / repolarization:
You can NOT see it, because it is behind the QRS complex.
The first heart sound (lub) is associated with what complex / segement on an EKG reading? Why?
QRS complex. Because as the ventricles contract, it causes the AV valves to close. This closure is the 1st heart sound (lub).
Go to RegisteredNurseRN.com for EKG quiz.
Go here for a REALLY REALLY GOOD QUIZ:
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https://www.practicalclinicalskills.com/ekg-practice-drill
For NORMAL TIMING of intervals, what is the normal time between:
- PR Interval:
- QRS Complex:
- QT Interval:
- PR Interval: 0.12-0.20 seconds
- QRS Complex: 1-3 boxes (0.04-0.12secs)
- QT Interval: < 0.40 seconds
EKG Paper Measuring:
1) How much time between each hashmark?
2) How much time between 2 hashmarks (or 3 total if you count the one at the front)?
3) When you interpret EKG’s you want to look at how long of a strip?
4) What is a BIG Box on an EKG strip (how many little boxes are in it and what time it represents)? VERTICALLY AND HORIZONTALLY
5) What is a LITTLE Box and what TIME it represents?
6) What SIZE does a LITTLE box represent?
7) How can you tell the Heart Rate looking at an EKG strip?
8) On an EKG strip, in one second, generally, that represents how many little and big boxes?
9) How many big and little boxes on an EKG strip represent 1mV
1) 3 seconds
2) 6 seconds
3) 6 seconds
4)
Horizontally
- Big Box: 5 little boxes across, each at 0.04 sec’s, so 0.20 seconds total across horizontally. Each little box is 1mm so big box is 5mm total across horizontally.
Vertically
- Bix Box: 5 little boxes up, each one is 1mm, so 5 mm up for big box. And one little box is 0.1 mV so for 5 boxes it is 0.5 mV up.
5) Little Box: 0.04 seconds (Horizontally)
6) Little Box: 1mm x 1mm
7) Count how many R waves (QRS complexes) there are between 6 seconds and times it by 10 (so if you get 6 in 6 seconds, HR = 60 bpm)
8) It is 25mm/sec, so 5 big boxes and 25 little boxes in a second on an EKG strip.
9) This is vertically … Each little box is 0.1mV, so 5 for a big box is 0.5mV. That means you’d need 2 big boxes and thus 10 little boxes to get 1mV (or 10mm).
How do you tell if you have a regular vs. irregular rhythm?
Get out your CALIPERS and measure between R and R waves (QRS complex to QRS complex). If it is the same distance between each R - R in the 6 seconds, then it is regular. If not, irregular.
1) How do you tell the difference between A-fib and A-flutter? What do you ask / look for to know?
2) Do you have a P Wave in A-fib or A-flutter?
3) A-fib is the pretty or the ugly sister?
4) Which one is typically a REGULAR beat?
1) Does it have a P Wave? NO - there is NO P wave in A-fib and a nice fluttery repeated P wave looking flows in A-flutter. But of there are 2 nice looking flutters, that equals sinus tachycardia. If there are 3 nice fluttery p waves, that is when it is A-flutter. A fib is IRRegular rhythm, A flutter is REGular rhythm.
2) A flutter
3) A-fib is the UGLY sister. The waves between R-R are all over the place and ugly. But the A-flutter is the pretty sister (flutters her eyes) because the waves are nice and smooth and look much better.
4) A flutter is usually regular, A fib is NOT a regular beat.
ECG stands for =
What is an ECG - what does it do?
Is ECG and EKG synonymous? Why?
What is an Echocardiogram:
Electrocardiogram
The ECG records the electrical signal of the heart as the muscle cells depolarize (contract) and repolarize.
YES, they are the same. They replaced the K with C because ECG sounded like EEG which is a neural screen.
Echocardiogram: The echo test or heart ultrasound,
is a test that takes “moving pictures” of the heart with sound waves to look at heart health.
What generates the initial electrical impulse and begins the cascade of events that results in a heart beat.
Normally, the SA Node.
Cardiac cells resting have what charge?
What is the charge during depolarization?
What is the charge during repolarization?
Cells that are resting have a NEGATIVE charge with respect to their exterior.
Depolarization consists of POSITIVE ions rushing into the cell.
Repolarization is when positive ions rush out of the cell causing the cell to go back to a NEGATIVE charge.
Is there a difference between the EKG graph and a single cell depolarization graph?
Explain the 4 phases of a single cardiac cell graph:
Which Phase is Depolarization?
Which phase is repolarization?
YES. EKG shows the PQRST complexes … the entire cardiac cycle. Where a single cardiac cell is just the graph of one cardiac cell (looks like a sail boat).
Phase 4: Cell is resting potential of a -90mV (Na+ and Ca+ channels closed, K+ channels open).
Phase 0: Action potential hits cell and Na+ channels open and Na+ floods IN to cell. (line goes from resting straight up).
Phase 1: At the peak, K+ channels open again and K+ flows OUT (causing line to slightly dip)
Phase 2: Influx of Ca+ IN to cell, and K+ out (so it balances … causing line to plateau).
Phase 3: K+ goes OUT causing charge to go back to negative (resting potential).
Phase 4: Flat line before another depolarization where Na+ and Ca+ channels are closed and K+ are open. REPEATS
Depolarization: Phase 0-2
Repolarization: Phase 3
T or F: Electrical activity / action potential / stimulation = repolarization?
T or F: With depolarization, the membrane is more permeable to sodium ions, allowing them to flow inward and creating a positive charge on the inside.
T or F: A cell at rest has a positive charge, while outside the cell is a negative charge?
How and why do the cells rush in / out of cells?
False. It is DEpolarization. Electrical stimulation to the cardiac muscle cell membrane causes depolarization.
True
False. A cell at rest has a negative -90mV charge, and outside the cell is Na+ and Ca+ ions that create a positive charge on the outside / transmembrane. AND - during depolarization, it switches.
It is all about diffusion from high concentration to low concentration based on the action potentials opening the gates to allow flowage of these ions. And action potentials change the gated channels allowing ions in/out.
With EKG’s:
1) What is an electrode:
2) What does an electrode measure?
3) What type do hospitals use?
4) What will we use in class?
5) How many leads are in a 12-lead EKG
6) RA =
7) LA =
8) RL =
9) LL =
10) V1-V6 =
11) Do all 12 leads say the same thing?
1) Electrode: Pad that sticks onto patient to detect electrical activity of heart.
2) Electrical activity of the heart from varying places / angles of electrodes all over the body.
3) 12-lead EKG
4) 5-lead EKG
5) 10 leads
6) Right arm (electrode)
7) Left arm (electrode)
8) Right leg (electrode)
9) Left leg (electrode)
10) Various places along chest underneath heart where you place electrodes
11) All 12 leads / electrodes are the same heart and beat, they just shows different angles / leads of the electrical activity.
Just know that EKG’s today are pretty similar to what was created originally / historically. Heart is placed in the middle of a triangle (two arms and Left leg) about the body to pick up electric signals from the randomly placed electrodes.
Willem Einthoven developed the EKG system.
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What is the Einthoven triangle?
What are Leads I, II, III
If ever in doubt, look at which lead?
What are:
- aVR =
- aVL =
- aVF =
V1-V6 leads that are close to the heart are called:
Briefly explain where each of the V1-V6 leads are placed, and why - or what they measure?
From RA -> LA -> down to LL -> back up to RA. This is the triangle. Heart right in the middle.
Lead I: RA to LA
Lead II: LA to LL
Lead III: LL to RA
Lead II
- aVR - right arm
- aVL - left arm
- aVF - left leg
PRECORDIAL LEADS
Leads V1 and V2: are placed over the right side of the heart (measuring RV)
Leads V3 and V4: are located over the interventricular septum
Leads V5 and V6: demonstrate changes on the left side of the heart (measuring LV).
Accronym to remember for the 5-leads set up and what electrode goes where:
W = white (right) G = green (grass) B = black (smoke) R = red (fire) V1 = brown (crack)
White = right
Clouds (white) over Grass (green)
Smoke (Black) over Fire (Red)
Brown (V1) in the crack
Which one, from the two below, look at the entire heart, and which one looks at just one cardiac cell?
Ventricular Action Potential (Graph)
EKG (Graph)
Ventricular Action Potential (Graph) = looks at one mycardial cell
EKG (Graph) = looks at entire heart
What is the primary pace maker of the heart?
If the primary pace maker gets knocked out, then what is the back up pace maker?
If the back up gets knocked out, then what is the back up to the back up?
SA Node
Then AV node takes over
Bundle of His and Purkinjie fibers take over
Pace from the SA Node is:
SA Node would be 100 bpm if it weren’t for what:
Pace of AV Node is:
Pace of Purkinjie fibers (or ventricular cells) is:
SA Node: 60-100 bpm
Vagus nerve slowing it down
AV Node / JUNCTION: 40-60 bpm
Bundle and Purkinjie fibers: 20-40 bpm
The heart behaves as a syncytium. What does that mean?
How many syncytia of the heart are there?
A network of cardiac muscle cells connected by gap junctions that allows coordinate contraction of the atria. So, once a wave is initiated, it continues to propagate uniformly into the remaining myocardium that is still at rest (“all or nothing” concept).
There are two syncytia of the heart: the ventricular syncytium and the atrial syncytium separated by fibrous tissue.
How do you calculate the Heart Rate from an EKG strip?
The heart rate can be determined by identifying 6 seconds on the electrocardiogram paper and counting the number of QRS complexes in the 6-second strip. The number of QRS complexes in 6 seconds multiplied by 10 gives the heart rate for 1 minute.
Oxygen debt or oxygen deficiency to the heart is called:
It can lead to what:
T or F: An infarcted area of the heart would not give out an electrical signal on an EKG
ST segment ELEVATION (on an EKG) indicates =
ST segment DEPRESSION indicates =
Ischemia
MI
True
MI
Ischemia
1) Review the path of the conduction of the heart:
2) What is the atrial kick (or AV node delay), and why is it important?
3) What segment on PQRST graph is the Atrial kick?
4) Electrical pulse (pace maker) is initiated and controlled by what:
5) SA node is where on heart:
6) How does electrical activity go from RA to LA (what is it called specifically)?
7) P wave =
8)
- Signal flows from SA node to AV node through what?
- And right before AV node sends signal, what happens?
9) After the AV node, electrical signal goes where … what is its path?
10) Ventricular contraction / depolarization is what on the PQRST graph?
11) S-T segment is what:
12) S-T interval is what:
1) SA Node -> AV Node -> Bundle of HIS -> L and R Bundle Branches -> Purkinjie Fibers
2) Atrial kick is when there is a slight pause before AV node sends signal to ventricles. This allows atria to get the rest of the blood out into ventricles. The priming force contributed by atrial contraction immediately before ventricular systole that acts to increase the efficiency of ventricular ejection due to acutely increased preload. Increases EDV and thus EF to improve SV and CO.
3) P-R segment
4) SA node
5) RA (back part of it)
6) Through the inter-atrial bundles called Bachmann bundle
7) Atrial depolarization
8)
- Internodal pathways.
- Atrial kick
9) From AV node to Bundle of HIS, then R and L bundle branches down to purkinjie fibers.
10) QRS complex
11) S-T Segment: Final part of ventricles contracting to when ventricles start repolarizing / relaxing. From end of S to start of T. (S = S … Segment = Small). S-T segment really is when blood is now going into Coronary Arteries … that is why an elevated ST segment (STEMI) indicates an MI).
12) S-T Interval: From S to end of T when ventricles are repolarizing and relaxing.
1) What is the Bachmann bundle?
2) P-R interval is what:
3) T or F: The L and R bundle branches are located in the interatrial septum?
4) T or F: The right bundle branch has both an anterior and posterior division/branch?
1) The pathway allowing electrical signal to get from SA node in RA to the LA
2) Atrial depolarization + atrial kick
3) False. They are in the interVENTRICULAR septum
4) False. It is the LEFT bundle branch that DOES have an anterior and posterior division.
How does the S-T segment typically look in a normal healthy heart?
What is the J point?
Why is the S-T segment important to look at?
So why would the J point be important?
Flat line
The J point is at that bending part where QRS segment is ending and it is rounding out to the flat line over to the T wave (shape of J).
This segment is important because if it is elevated, it might imply or MI, and if depressed it would indicate ischemia. It is when the coronary arteries are filling with blood.
The J point is also the beginning of the ST segment and is often used as the landmark when the ST segment is aberrant/abnormal. When that J point area is abnormal, it is a red flag (see point above in a few flashcards up).
1) STEMI stands for what:
2) What is the ST of STEMI:
3) What is a STEMI heart attack:
4) If someone had a STEMI, how would it appear on an EKG?
5) What is a non-STEMI or NSTEMI?
1) ST-elevation Myocardial Infarction.
2) ST segment on an EKG
3) STEMI heart attack, happens as a result of a COMPLETE (100%) blockage in a coronary artery. A STEMI attack carries a great risk of death and disability.
4) The J point would be off (high, angled, abnormal) and then ST segment would not be flat like normal, but be high, rounded, angled, abnormal).
5) Non-STEMI: When an artery is PARTIALLY blocked and severely reducing blood flow to coronary arteries, a non-STEMI heart attack may occur. ST segment is depressed, or T wave is inverted.
T or F: You are not treating an EKG strip, you are treating a person. There is a LOT more that goes into the patients health besides an EKG reading.
True
***** There are 5 steps of Rhythm Analysis (Or EKG/ECG tracings). What are they:
Explain each step:
Step 2: Determine regularity. Step 1: Calculate rate. Step 3: Assess the P waves (and P wave with QRS). Step 4: Determine PR interval. Step 5: Determine QRS width or duration.
Step 2: Is the rhythm regular. Measure from R-R with caliper or paper. Is it regular or not? See if R-R and P-P is regular.
Step 1: What is the heart rate? Is it within the normal range of 60-100 bpm? (3 ways to do this)
Step 3: Are all P waves normal and present in recognizable form? Is it associated with a QRS complex? Is it upright, or upside down, or missing? Is there one QRS complex for each P wave?
Step 4: Is the P-R interval consistent in length, or increasing, or short? Normal being 0.12-0.20 seconds.
Step 5: What is the duration between the widest part of the QRS complex. Normal range being 1-3 boxes (so 0.04-0.12 seconds).
*** Refer to my flow chart / concept map, and this link:
http://www.nclexquiz.com/wp-content/uploads/2016/03/ECG-Interpretation-Flowchart.jpg
For step 1, there are 2 options to calculate the heart rate. What are they:
How do you DOUBLE CHECK / BACK UP PLAN:
1) IF REGULAR: Get ruler and measure distance between 3 QRS complexes (which is 4 from start to end). Lets say you got 50mm. Then do: 4500/50 = 90bpm
(***Option 1 only works if the R-R interval is regular).
2) If IRREGULAR: Count how many COMPLETE cardiac cycles are in a 6 second period (between 2/3 hashes). Then times by 10. So if you got 7 R waves (complete cycles): 7x10 = 70 bpm.
DOUBLE CHECK:
3) Find an R wave that starts on a bold line / big box line. Count the # of large boxes to the next R wave. Then count down from 300, 150, 100, 75, 60, 50 for each large box between an R wave. Where the next R wave falls between big boxes tells you roughly HR.
For step 2, how do you determine regularity with heart beats?
Use a caliber (or whatever you have) and measure between R-R waves. If it is regular and consistent between each = normal. Irregular is abnormal.
1) IF REGULAR: Get ruler and measure distance between 3 QRS complexes (which is 4 from start to end). Lets say you got 50mm. Then do: 4500/50 = 90bpm
(***Option 1 only works if the R-R interval is regular).
2) If IRREGULAR: Count how many R waves (tips) are in a 6 second period (between 2/3 hashes). Then times by 10. So if you got 7 R waves: 7x10 = 70 bpm.
1) For step 3 of assessing P waves, what are you looking for:
2) If the P waves are normal, symmetrical, consistent, that means what?
3) If P waves are NOT, that means what:
4) T or F: Normal P waves have 1 P wave for every QRS
1)
- Are there P waves?
- Is the P wave upright, upside down, missing?
- Do the P waves all look alike?
- Do the P waves occur at a regular rate?
- Is there one P wave before each QRS?
2) If normal, then that means the action potential is coming from the same place (SA node) each time.
3) If abnormal P wave, atria are getting action potentials from different spots. Or AV node or ventricles have taken over as pacemaker.
4) True
1) Sinus Rhythm means:
2) NSR =
3) NSR means what?
4) NSR Parameters =
5) What is it called if rhythm does not conduct normally?
6) If SA node beats too fast it is called:
7) If SA node beats too slow it is called:
8) When is Sinus Tachycardia ok?
9) When is Sinus Bradycardia ok?
1) Sinus rhythm means a NORMAL heart beat, that is the same and consistent both with respect to the heart rate and rhythm. Heart rate will fall between 60 and 100 beats per minute. The shape of the electrocardiogram (EKG) tracing will exhibit certain key attributes to be considered normal, as discussed below.
2) NSR = Normal sinus rhythm
3) NSR = it was conducted in the SA node normally (with all other steps being normal too … see next point)
4) Rate 60 - 100 bpm Regularity regular P waves normal PR interval 0.12 - 0.20 s (3-5 boxes) QRS duration 0.04 - 0.12 s (no more than 3 boxes)
5) Arrhythmias (or dysrhythmias)
6) Sinus Tachycardia (more than 100 bpm)
7) Sinus Bradycardia (less than 60 bpm)
8) Sinus Tachycardia may be an appropriate in response to stress or activity (EXERCISE). So faster HR than 100 does not necessarily mean pathology. Depends on person and situation.
9) Sinus Bradycardia may be normal in a well conditioned individual, or just really relaxed.
Step 4 of determining the P-R interval, what is the normal amount of time and how many boxes:
0.12-0.20 seconds (3-5 boxes)
This is from start of P wave (atrial depolarization) to start of QRS complex (ventricular depolarization).
Step 5 of QRS complex, in a normal heart, this complex is how wide, lasting how long?
If QRS complex was 2 boxes wide, it is how long?
1-3 boxes … 0.04 - 0.12 seconds
0.08 seconds
What are these:
- Sinus Arrhythmia:
- Sinus Block:
- Sinus Arrest:
Sinus Arrhythmia - inconsistent heartbeat. Everything on PQRST graph is the same, but the P to P interval varies a bit. Not a huge deal, this happens fairly often in most people.
Sinus Block - SA node fires but impulse fails to conduct beyond node. So, if the R-R interval measurement MISSES A BEAT exactly (regularily). But if more than that = sinus arrest.
Sinus Arrest (pause) - Sinus node just does NOT fire. Abnormal if > 3 seconds.
If you miss a beat, is that ok?
When is it abnormal?
Not a huge deal, this happens fairly often in most people.
If it lasts longer than 3 seconds
Just found this great resource … go PRACTICE. It is VERY GOOD REVIEW:
https://ekg.academy/learn-ekg?courseid=313&seq=8
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1) T or F: Whenever you see an EKG strip, you must go through the 5 steps?
2) If you go through all 5 steps and everything is normal, what is that called:
3) So if you get a NSR, what will you see:
4) If you find tachycardia or brachycardia during step 2, will all the other steps be normal, or could those be off too?
1) True
2) NSR = normal sinus rythym
3) The rhythm will be regular (1); in a heart rate range between 60 – 100 bpm (2); P waves are upright and uniform in appearance (in Lead II), with a P wave for each QRS complex (3); the PR interval will measure in the normal range of 0.12 – 0.20 second (and measure the same each time) (4); and the QRS complex morphology will be similar beat-to-beat and measure between 0.04 – 0.12 second (and measure the same each time).
4) Typically everything else will be normal except a fast or slow HR.
