Cardiac Arrythmias Flashcards
Normal path of impulse through nodes
SA node–> AV node–> Bundle of His–> Bundle branches–> Purkinje fibers
P wave patho
Atrial depolarization
QRS patho
ventricular depolarization
T wave patho
ventricular repolarization
PR patho
Atrial depolarization with a delay in AV junction
why is there a delay in the AV junction
allows time for the atria contract before the ventricles contract
pacemakers of the heart:
SA Node
dominant pacemaker rate.
60-100 bpm
Pacemakers of the heart:
AV node
back up pacemaker
40-60 bpm
Pacemakers of the heart:
Perkinje fibers
2nd back up pacemaker
20- 40 bpm
Normal sinus rhythm (NSR)
-where does impulse start
-impulse formed in the SA node
all rhythms that start this way are “normal”
NSR parameters
- rate
- regularity
- P wave time
- PR interval
- QRS duration
- 60-100 regular normal, present 0.12-0.20 0.06-0.10
Arrythmias can arise from:
- SA node
- Atrial cells
- AV junction
- ventricular cells
SINUS Arrythmias
-type
- Sinus bradycardia
- Sinus tachycardia
- sinus arrythmia (NOT TESTED)
- Sinus arrest (not on test)
- sinus block (not on test)
SA nodes Problems
- fires too fast
- fires too slow
- -sinus tachycardia
- sinus bradycardia
Sinus Tachycardia
everything normal except rate between 101-150
*150 is max!
Sinus Tachycardia causes
medications fever pain anxiety dehydration pulmonary embolus CHF
Sinus tachycardia treatments
Make sure to treat the underlying cause
- if fever give tylenol
- if CHF give diuretic
Sinus bradycardia
everything normal except heart rate below 60
Sinus bradycardia causes
medications
athlete
brain injury
Sinus bradycardia treatment
-when to treat?
ONLY if symptomatic
- chest pain
- hypotension
Sinus bradycardia treatment
-order of treatment
- Atropine 0.5-3 mg
- Transcutaneous pacing
- Dopamine 2-10 mcg/kg/min
- Epinephrine 2-10 mcg/min
Types of ATRIAL arrythmias
- atrial fibrillation
- atrial flutter
- supraventricular tachycardia
- premature atrial contraction **this is an event, not a rhythm
Atrial arrhythmias
-Premature atrial contractions
atrial cells fire occasionally from a focus
Atrial arrythmias
-Atrial flutter
atrial cells fire continuously due to a loooing re-entrant circuit
Atrail flutter patho
re-entrant circuit keeps looping around in the atria and finally makes it to the ventricles (looks like continuous waves and then bolts to a normal rhythm)
Artial arrythmias
-Atrial Fibrillation
-atrial cells can fire continuously from multiple foci or continuously due to multiple re-entrant “wavelets”
Atrial fibrillation patho
colliding wavelets generate fine choatic impulses. they in turn create new foci of activation (quick, short, jerky waves)
Atrial fibrillation
- rhythm
- p waves
- PR interval
- QRS
- rate
ALWAYS IRREGUALR -no P waves, F waves -PR interval not measurable -normal QRS 60-100
Atrial Flutter
- rhythm
- p waves
- PR interval
- QRS
- rate
-regular or irregular
-no p waves, **F waves are sawtooth
-PR interval not measurable
-normal QRS
60-100
Atrial Fibrillation causes
MI
lung dz
valvular heart dz
hyperthyroidism
Atrial Fibrillation treatment
calcium channel blockers
beta blockers
digoxin
anticoagulants
How do you treat Atrial fibrillation if the patient is Unstable?
CARDIOVERSION.
What is cardioversion
shocks patient when the ventricles contract–> sends them from atrial fibrlilation to NSR
what must you give the patient BEFORE cardioversion if they have been in atrial fibrillation for >48 hours?
Give anticoagulants to break up clots
Supraventricular Tachycardia (SVT)-
- where
- rate
- rhythm
- p waves
- PR interval
- QRS
- above the ventricles
- 151-250
- regular
- p waves hard to identify because beating so fast
- PR
What is unique about Supraventricular Tachycardia
There is no other rhythm that beats >150 and has a normal QRS and rhythm
Supraventricular tachycardia (SVT) treatment
- vagal maneuvers
- adenosine IVP with 10-20 ml of saline
- adenosine 12 mg IVP with 10-20 ml of saline
- Cardiversion (50-100 J)
when you give pt’s beta blockers and CCBs, what effect does it have on the heart?
These SLOW down the RATE, but do not covert the rhythm to NSR
What must you give to a patient when performing cardioversion?
SEDATION meds, (Versed 1-2mg)
Vagal maneuvers
Cough, bare down, suction
How does adenosine affect the heart?
makes them flat line for
3 Early Beats
1) Premature atrial contraction (PAC)
2) Premature Junctional Contraction (PJC)
3) Premature Ventricular contraction (PVC)
- these are 1-2 beats, not rhythms
Premature atrial contraction (PAC)
- causes
- treatement
- normal.
- decrease caffeine intake
Premature Junctional Contraction (PJC)
- causes
- treatment
- Digoxin toxicity
- HOLD the digoxin
Premature Ventricular contraction (PVC)
- causes
- treatment
- heart disease, hypokalemia, hypoxia
- give AMIODARONE (anti-arrhythmic)
PAC wave differences
- p wave
- QRS
P wave present
normal QRS
PJC wave differences
- p wave
- QRS
- p wave inverted or absent
- normal QRS
PVC wave differences
- p wave
- QRS
- NO p wave
- wide QRS
Junctional Arrhythmias
1) Junctional rhythm
2) Accelerated Junctional Rhythm
3) Premature Junctional Contraction PJC
where does the Junctional arrhythmia originate
the AV node (backup pacemaker)
Junctional Rhythm
- p wave
- QRS
- rate
- absent, inverted, or after QRS
- normal QRS
- 40-60 bpm
Accelerated Jinctional rhythm
- p wave
- QRS
- rate
- absent, inverted, after QRS
- normal QRS
- 61-100
Causes of Junctional arrhythmias
DIGOXIN TOXICITY
- SA node ischemia
- myocarditis
- valvular heart disease
- MI
Treatement of Junctional arrhythmias
Hold the DIG
- if symptomatic from bradycardia:
- - give atropine
Bundle branch block
- cause
- change seen in strip
- result of heart disease
- QRS >0.10 sec
- always an underlying rhythm
Bundle Branch block treatment
NO treatment
1st degree AV block
-pathophysiology
prolonged conduction delay in the AV node or Bundle of His
- always an underlying rhythm
1st degree AV block
-PR interval
> 0.20 seconds
1st degree AV block
-causes
- AV node ischemia
- age related changes in heart
- digoxin toxicity
- side effects from BB or CCB
1st degree AV block
-S/S
patients are NOT symptomatic
1st degree AV block
-treatement
treat underlying cause if possible
2nd and 3rd degree AV block
- rhythm
- p waves
- **NO UNDERLYING RHYTHM
- ** MORE P waves than QRS complexes
2nd Degree AV Block Type 1:
- also known as
- pathophys
Mobits 1 or Wenckeback
- each atrial impulse ecounters a longer and longer delay in the AV node until one impulse (usually the 3rd or the 4th) fails to make it through the AV node
2nd Degree AV Block Type 1:
-change from NRS
- PR interval lengthens until p wave not followed by a QRS
* * Rhythm always IRREGULAR
2nd Degree Block type 2:
-pathophys
condunction is all or nothing (no prolonged PR interval)
-blocks typically occur in the Bundle of His
2nd Degree Block type 2:
-change from NSR
P wave NOT followed by QRS
PR interval always constant
rhythm regular or irregular
3rd Degree AV block
-pathophys
there is a complete block of conduction in the AV node, so the atria and ventricles form impulses independently of each other
-without the impulses from the atria, the ventricles’ own intrinsic pacemaker kicks in around 30-45 bpm
3rd Degree AV block
-change from NSR
- p waves completely blocked
- no relationship between QRS and p waves
Interpreting AV blocks:
what does it mean if there a p waves “kissing” without a QRS inbetween them?
it is a 2nd or 3rd degree block!
Can P’s Kiss?
-STEP 1
measure PR intervals for the entire strip
1) constant: 2nd degree block type 2
2) variable: need to go to step 2
Can P’s Kiss?
-STEP 2
check regularity of the rhythm from R-R complexes
1) Regular: third degree block
2) Irregular: 2nd degree block type 2
Idioventricular Rhythm
- originates where
- rate
- rhythm
- P waves
- QRS
- in the ventricles
- 20-40
- regular
- NO P WAVES
- WIDE AND BIZARRE QRS
Idioventricular Rhythm
- cause
- treatment
-massive cardiac damage or hypoxia
-bradycardia treatment
-
Accelerated Idioventricular Rhythm
- originates
- rate
- rhythm
- P waves
- QRS
-ventricles with a HR faster than ventricular rate
-41-100
regular rhythm
-NP P WAVES
-WIDE AND BIZZARE QRS
Accelerated dioventricular Rhythm
- cause
- treatment
- massive cardiac damage or hypoxia
- bradycardia treatment
Ventricle cell problems
1) PVC
cells fire occassionaly from 1 or more foci
Ventricle cell problems
2) Ventricualr fibrillation
cells fire continuously from multiple foci
Ventricle cell problems
3) Ventricular tachycardia
fire continuously due to a looping re-enternt circuit
Ventricular tachycardia
- rate
- rhythm
- p wave
- qrs
- > 100
- regular
- NO P WAVES
- WIDE QRS
Ventricular tachycardia
-cause
myocardial irritability
- HF
- MI
- Electrolyte imbalance
- rewarming during hypothermia
Ventricualar tachycardia
-treatment WITH A PULSE
Amiodarone 150 mg over 10 min
or synchronized cardioversion
Ventricular tachycardia
-treatment WITHOUT A PULSE
- CPR
- defibrillation (200 J)
- Epi 1 mg during CPR
- Amiodarone
- Epi or vasopressors
Whats the first thing you should do when you see a pt with V-tachy
check for a pulse!
Torsades de Pointes
- what is it
- rate
- rhythm
- P waves
- QRS
- form of V-tachycardia
- > 200
- regular or irregular
- NO P waves
- WIDE QRS
treatment for Torsades de Pointes
usually caused by low Magnesium, so treat it with 1-2 gram IV Magnesium
Torsades de Pointes:
-treatment for UNCONSCIOUS PT
ONLY rhythm that you can use DEFIBRILLATION WITH A PULSE
Ventricular Fibrillation
-patho
ventricles wiggle instead of contract
Ventricular Fibrillation
- rate
- rhythm
- p waves
- QRS
- cant determine rate, rhythm
no p waves
no QRS- just wavey, spiked baseline
Ventricular Fibrillation
-cause
caused by the same as V-tach: myocardial irritability -HF -MI -Electrolyte imbalance -rewarming during hypothermia
Also near drowning, drug overdose, accidental shock
Does V-fib ever have a pulse?
NO!
Treatment for V-fib
- CPR
- Defib
- Epi or vasopressin
- defib
- amiodarone 300 mg
- epi
- amiodarone 150 mg
Asystole
-pathophys
ALL pacemakers of the heart have failed!
absense of electrical activity
Asystole
-causes:
H’s and T’s
H’s
-hypovolemia hypoxia hydrogen ion (acidosis) hyp/hyperkalemia hypothermia
T’s
Tension pneumothorax
- tamponade
- toxins
- thrombosis
Asystole
-treatment
Reverse the H & Ts
cardiac arrest guidelines
Pulseless Electricle Activity (PEA)
-pathophys
there is electrical activity but NO MECHANICAL activity
PEA
- rhythm
- pulse
- cause
- tx
- any rhythm
- NO PULSE
- caused by H & T
- tx same as asystole
Immediate Post Cardiac Arrest Care
1) Oxygenation/intubation
2) treat hypotension
Hypothermic protocol
-rational
only txt that improves neurological functioning
Hypothermic protocol
-effect on body
stops metabolic demand
stunts inflammatory process
methods for inducing hypothermia
-invasive
foley catheter
NG
central line
methods for inducing hypothermia
-non- invasive
ice packs
cooling blanket
environmental temp
what must you give when inducing hypothermia
PARALYTIC
SEDATION
PAIN MED
Paced rhythm:
1) atrial paced rhythm
Spike BEFORE p wave
Paced rhythm:
2) Venticular paced rhythm
spike BEFORE QRS
paced rhythm:
3) atrial and ventricular
spike BEFORE p and QRS
paced rhtyhm:
- failure to capture
- tx
pacer spikes NOT followed by a P wave or QRS
- increase output setting
paced rhythm
- failure to sense
- tx
pacemaker spikes too closely behind QRS complex
- not sensing the heart beat
- increase sensitivity
