EKG Notes v2 PDF

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After SA node fires, it sends impulses throughout atrial and causes atrial contraction. A lot of its impulse will travel to AV node. There’s a delay from the AV node to the interventricular septum - Bundle of His AV node will conduct towards Bundle of His. Bundle of His to the Purkinje fibers Purkinje fibers that creates ventricular contraction. Cardiac Sinus Rhythm – Lub dub

EKG – graphic representation of the electronegativity of the heart as the impulse travels from the SA node, AV node, Bundle of His, and Purkinje fibers. It pictures a rhythm called sinus rhythm. It represents the impulse from the sinoatrial node. Sinus rhythm means it follow the normal electronegativity of the heart.

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Contraction of the atria. The contraction of the atria is presented by a wave called P wave. P wave is characterized by a circular upright wave. P wave runs from 0.12 seconds to 0.2 seconds.

Lead 2 always shows the upright contraction. Leads are placed in different precordial sites on the chest. Only lead 2 and lead 5 shows the upright deflection of the P wave. The contraction of the atrium is lesser in intensity than the contraction of the ventricles. Before there’s a ventricle contraction on the Purkinje fibers, there will be a delay 

PR interval – time in which the impulse travels from the (AV node) atrium before it stimulates the ventricular contraction; purpose is to fill the ventricle with blood so when the impulse reach the Purkinje Fibers so it can stimulate the ventricular contraction o 0.20 seconds (from start of the P wave to the start of QRS complex) o the whole P to the beginning of the R; onset of the QRS complex o Starts at the P wave and contracts the atrium o End of the PR interval contracts all atrium and the Bundle of His o The time the impulse spread from the atrium and travels to the AV node and bundle o The time the ventricle is relaxing because the ventricles is still being filled with blood o Ventricular filling and ventricular repolarization 

PR segment – flat line from the beginning of Q. The PR segment reflects the time delay between atrial and ventricular activation. The PR segment also serves as the baseline (reference line or isoelectric line) of the ECG curve. The amplitude

There is only one stylus on the EKG, and it will only record the strongest contraction. It will record the atrial contraction followed by the ventricular contraction.  

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Ventricular contraction on the Purkinje fibers is represented by a complex It is considered a complex because there is a wave that is going down, up, and down again Ventricular contraction is when the Purkinje fibers receives the impulse and creates a very strong contraction. The intensity of the ventricular contraction is too much, instead of being rounded, it creates a pointed wave and not only one wave, it creates 3 waves o Q – downward deflection o R – upward deflection o S – downward deflection

QRS complex: 0.08 seconds Because of the strength, it creates the pointed complex but narrow (characterized as narrow) P wave precedes the QRS complex = atrial contraction precedes ventricular contraction

if P wave and QRS complex contracts at the same time, QRS complex will be presented on the EKG since ventricles is stronger all the time o R wave represents the whole QRS complex. o R wave represents the QRS complex. 0.8 seconds

o T wave represents ventricular relaxation o Followed by another atrial contraction or P wave. That’s the sinus rhythm.

o There’s 12 lead EKG. o The lead is spread out in the chest in chest, upper limb, and lower extremities. o The leads looks at the heart in different planes. o The EKG looks at the heart in different planes. o In looking at lead placement, when you look at EKG always have lead 2 with it so that you have an upward deflection **Look at lead 2 to start with cause if you are on different lead, you will have a different findings. 

Each box represents 0.04 seconds If P wave goes beyond 0.12 seconds, it will affect

the HR. The longer it takes for the wave, the lesser the CO will result physiologically because it slows down the heart. 

Each big box represents 0.20 seconds How many big squares in one minute? 60 / 0.2 = 300 big squares

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It takes 300 big squares to get one full minute. Do not take the whole full minute, but rather obtain a 6 seconds strip. You just need 30 big squares. o 6 / 0.20 = 30 big squares Each triangle is 3 sec duration. You need 3 triangles to obtain 6 seconds. You have 15 big squares in 3 seconds. 3 / 0.20 = 15 big squares

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QRS interval – beginning of the Q until the S ST segment – from ventricular contraction to start of ventricular relaxation

o When ST segment is elevated, it is an indication of MI P wave interval includes the P wave but the PR segment does not P wave will normally have 0.12 to 0.20 seconds from beginning to the end of the atrial depolarization. PR interval is the beginning of the interval until it starts the QRS complex. The stop of the P and the start of the Q is the PR interval

1. 2. 3. 4. 5. 6.

Determine Obtain a 6 seconds strip IS there a P wave? Does P precede QRS complex? Is my Rs regular? Count the number of Rs Multiply it by 10

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Sinus rhythm at 90 bpm

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Sinus tachycardia at 150 bpm

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Sinus bradycardia at 40 bpm

2nd

3rd

PREMATURE ATRIAL CONTRACTION (PAC)     

Characterized by an isolated distortion of the P wave The atrial has a problem; the atria contracts twice and there’s an extra beat before the ventricular follows P wave precedes the QRS complex and the second contraction follows before the ventricles follow that creates a distortion in the P wave Early contraction of the atria PAC – Premature Atrial Contraction o Due to a secondary atrial contraction but it is isolated in the middle of sinus rhythm, but it does not distort the QRS complex o Creates a distorted upright P wave but a normal QRS complex in the middle of sinus rhythm o **too much potassium will start doing that

ATRIAL FLUTTER   

Characterized by regular irregularly loop P wave mimicking saw tooth in a normal QRS complex The problem is atrial since there is R present Are these Ps or Ts?

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o This is a P since the EKG records the stronger activity / atrial contraction o The T (ventricular relaxation) is hidden because the P wave is stronger than the relaxation Ectopic nodes – ectopic pacemaker – ACDE o After SA node is fired, the other ectopic nodes also fires which creates continuous P wave then finally ventricular contraction. o Depolarization is coming from something other than SA node o It creates a flutter (saw tooth look)  A flutter is an irregular but has regularity in shape, so it has some organization although it’s irregular o Called an ATRIAL FLUTTER There’s a regularity at least

ATRIAL FIBRILIZATION    

Characterized by an irregular chaotic with a regular QRS complex The P waves is disorganized. The problem is atria since the P wave is in chaos; the T wave is hidden because of the P wave Called ATRIAL FIBRILIZATION o Characterized by disorganization and irregularity but since it happens where the P should be

*There is still a pulse but there is little CO since there is a problem with preload

PREMATURE VENTRICULAR CONTRACTION (PVC) and COUPLET PVC 

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Premature ventricular contraction o R is wide and not narrow; wide bizarre isolated in middle of sinus rhythm o After the ventricles contract, it contracts again Caplet PVC o Two PVC in a row and they appear together o Ventricular problem o There could be a P hidden but since the ventricles is stronger, it hides the P wave

BIGEMINY PVC and VENTRICULAR TACHYCARDIA 

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Bigeminy PVC o At least two sets of sinus rhythm and a PVC o **only up to trigeminy Three or more PVCs in a row is a definition of a tachycardia (without a sinus rhythm) o Problems with the ventricles o Ventricular tachycardia o Look at the patient CO, there is no CO happening o Telemetry

**sinus tachycardia is not life-threatening compared to ventricular tachycardia What is the possible reason of sinus tachycardia? Increases metabolic demand, physical activity, caffeine intake, anxiety VENTRICULAR FIBRILATION and ASYTOLE 

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Ventricular Fibrillation o You cannot see the QRS complex, all you see is chaotic and disorganized QRS o Ventricle is quivering/shaking, a characteristic of ventricular fibrillation o There is a chaotic of the ventricular so there is ventricular fibrillation o If you do not respond to V-fib, it will lead to…. Asystole o No CO leads to death

**You don’t see a pulse cause the heart itself does not have any CO. The pulse is created by the gush of blood. If the heart doesn’t have CO, there is no pulse

NORMAL SINUS RHYTHM 1st DEGREE ATRIOVENTRICULAR BLOCK      

PR interval is lengthened – normal PR interval is 0.20 seconds (1 big box) Impulse travels so slow but it sill creates a ventricular contraction A delay of impulse traveling from the AV node to the Bundle of His There is no actual block, it is just slowing down of impulse to the AV node and Bundle of His It decreases the CO since it takes a long time to travel There is a delay of lub-dub

2nd DEGREE AV BLOCK TYPE 1/ MOBITZ TYPE 1/ WENKEBACH *only arrhythmia that has 3 names    

PR interval is getting longer and longer every time until it didn’t create a ventricular contraction Circle – there is no QRS complex There is an actual AV block, an actual AV block happens after the warning sign of lengthening PR interval A lengthening PR interval until it does not create a QRS complex

2nd DEGREE AV BLOCK TYPE 2/ MOBITZ TYPE 2   

There is a normal sinus rhythm or normal PR interval and suddenly there is no QRS complex There is an actual block It is not predictable

3rd DEGREE AV BLOCK/ COMPLETE HEART BLOCK 

The P wave is not always preceding the R

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There is an atrial and ventricular contraction, but it is not synchronized. Each creates their own Completely independent on its contraction...