Chapter 36 Flashcards
What are the intervalves of conduction?
P-R interval
QRS interval
Q-T interval
P-R interval
Amount of time to fill the ventricles
.20 or less
If >.20 we have a 1 degree AV block
ORS Interval
Represents time taken for deplarization (contraction) of both ventricles (systole)
.12 or less
If
Q-T interval
Represents time take for entire electrical depolarization and repolarization of the ventricles.
0.44 or less
If > 0.44 we have to treat the underlying cause with drubgs, electrolyte imbalance, or changes in H.R.
If the T wave is spiked (think electrolyte)
Hyperkalemia
If the T wave is flat
Hypokalemia
What does the 12 lead ECG show?
Structural changes, conduction disturbances, ischemia, infarction, electrolyte imbalance, and drug toxicity
Where do you place the 5 lead ECG?
R and L 7th ICS
V Lead on the right side of the sternum 3rd ICS
R and L 2nd ICS.
How can you determine a persons HR from an ECG?
count the number of QRS complexes in 1 minute..
Six Sec. Strip Method
If the conduction has regular rate and rhythm then you can count the number of QRS complexes in 6 sec and mult. by 10.
What does the P wave represent?
Atrial contraction (depolarization).
What is the small block method?
Count # of small squares between one R-R interval, divide by 1500
What is the big block method?
Count # of large square between one R-R Interval, divide by 300
What is the First degree heart block?
When the PR interval is larger than .20. No sinus rhythm, the AV node has taken over
What is a Bundle Branch Block?
When the QRS Complex is larger than .12. The conduction is only traveling through the bundle branch.
U Wave
Often over looked and is associated with electrolyte imbalance, heart disease, and HTN. Seen in hypokalmeia
How many bpm does the SA node provide
60-100
How many bpm does the AV node provide
40-60
How many bpm does the purkinje fibers provide
20-40
What are the three speed for junctional?
1) Junctional bradycardia-bpm are less than 40-60
2) Accelerated Junctional- bpm are greater than 60
3) Junctional Tachycardia-bpm are greater than 100
What three morphologies are in place for Junctional
1) When SA node is sick, P the wave is inverted
2) When SA node is knocked out. P wave is gone
3) the P wave is after the T wave
Stable vs. Unstable dysrhythmias?
Stable=Asymptomcatic or mild symptoms Unstable= Decreased perfusion/CO. (too fast, too slow) -Pulseless -Dizziness -Syncope -Hypotension -Chest pain -Shortness of breath
Syncope
Fainting
Head-up-tilt-test
Induce orthostatic hypotension (decrease BP, increase HR)
What are the different diagnostic Tests we can use for dsrythmias?
Cont. ECG monitoring Transesophageal echocardiogram Electrophysiologic Study Holter monitoring Event monitoring (loop) Excercise treadmill testing
What medications are used for dysrhythmias and why?
Atropine - bradycardia
Adenosine - tachycardia
Epinephrine- Cardiac arrest
Amiodarone- VFibb and VTach
What do you flush medications with?
20 mLs of NS to circulate
Explain how you would administer Adenosine?
First you would fast push 6 mg = 1st dose
Then you can push 12 mg = 2nd dose
When would you encourage vagal stimulation?
To slow down the heart = tachycardia
Where do you NEVER want conduction to spike?
On the T wave b/c it can cause ventricular tachycardia
What are the two malfunction that can occur with Pacemaker monitoring?
Failure to sense-Pacemaker isnt meeting the conduction pattern. Not spiking at the right place.
Failure to capture- Pacemaker isnt carrying out conduction after it spikes.
What are some main teaching points for a pacemarker>
- Avoid large magnets and electromagnetic fields
- Dont use a cell phone on the same side as the device or place over the device
- May set off metal detectors
- Monitor pulse daily
- Wear med alert braclet
What are some complication after CPR
-Sternum and rib fractures
-Liver and spleen lacerations
Pneumothorax
-Cardiac tamponade
Defibrillation is used for
Is used only for pulseless VT and VF.
- nonsynchronized
- no QRS
Cardioversion is used for
Used for Afib, Aflutter, SVT
- synchronized
- QRS
How do you use a defibrillator?
Pick appropriate energy level -Monophasic 360 -biphasic 200 Turn of synch switch Apply conductive mater Charge fibrillator yell clear Deliver charge
How do you used a cardioversion
Synchronzied circuit delievers a countershock to occur on the R wave of the QRS Complex.
- Pick appropriate energy lever (50-100)
- If non emergent sedate pt
- Turn on synch switch
- apply conductive matter
- Charge cardioversion
- yell clear
- Deliever charge
When would a pt recieved and ICD (Implanted Cardioverter Defibrillator)?
If they survive SCD (Sudden Cardiac Death)
Important facts about ICD’s
- Deliever 25J shock
- Can have a combo (Pacemaker included)
- If it fires more than once call EMS
What is Radiofrequency Catheter Ablation Therapy
- Electrical energy used to burn ectopic areas
- SVT’s
- used for atrial dysrhytmias
What do you do after ROSC (Return of spontaneous ciruclation)
therapeutic hypothermia
Sinus means…
Impulse came from the SA node.
What is Normal Sinus Rhythm
-Reg. PQRST cycles
-Rate b/w 60-100
P wave before each QRS complex
-Narrow QRS complex (0.12)
-All complexes look the same
Sinus Bradycardia
- We have reg PQRST cycles
- Rate is slowed to less than 60 bpm
- P wave before QRS
- Narrow QRS
- All complexes look the same.
TX: 1) Oxygen 2) Atropine 3) Pacemaker
Sinus Tachycardia
CB: Exercise, fever, pain, hypovolemia, meds
- Reg PQRST cycles
- Rate is too fast b/w 101-200 bpm
- P wave before each QRS complex
- Narrow QRS
- All Complexes look the same
Tx: Treat the underlying cause
Sinus Arrhythmia
Normal phenomenon of mile acceleration with inspiration and slowing of the heart rate with expiration
No Tx
- Irregurlar PQRST cycles (Q waves dont match up)
- Rate slightly abnormal
- P wave before each QRS Complex
- Narrow QRS
- All complexs look the same
Premature Atrial Complex (PAC)
Abnormal electrical shock that is picked up by the AV node cuaseing the rest of the heart to fire.
- Regular PQRST
- Rate is normal with one interval that dosent belong
- P wave before each QRS complex
- Narrow QRS
- All complexs look the same
CB: Emotional stress, fatigue, caffeine, tobacco, alcohol, meds
tx: Decrease sources of stimulation
Isolated occurances are normal
Tachydsyrhythmias
HR > 100 bpm
Decrease supply/ Increases Demand
Dysrhythmias
Atrial!! -Aflutter -Afib -SVT (Cardioversion/ Synchronized)
What do you treat dysrhythmias with?
Adensoin
What are 4 types of Atrail Dysrhythmias?
1) PACs’
2) SVT
3) Atrial Flutter
4) Atrial fibrillation (most common)
