Dysrhythmias Flashcards
Pacemaker of the heart
SA node
Atrial depolarization
SA node to AV node
Contraction of atrium
Ventricular depolarization
AV node to Bundle of His to Purkinje fibers
Contraction of ventricles
Calculate heart rate on EKG strip
Between R to R waves in 6 seconds (FULL cycle) and multiply by 10
Small box
0.04 seconds
Big box
0.20 seconds
PR interval
0.12-0.20 seconds
QRS interval
<0.12 seconds
QT interval
0.34-0.43 seconds
Straight line on EKG
isoelectric line
What does the isoelectric line mean?
NO electrical conduction
Above isoelectric line
Positive deflection
Below isoelectric line
Negative deflection
What does the PR interval represent?
Atrial depolarization
SA node to AV node
What does QRS interval respresent?
Ventricle depolarization
AV node to Bundle of His to Pukinje fibers
What does T wave represent?
Ventricular repolarization
Normal sinus rhythm
60-100 bpm
Sinus Bradycardia
<60 bpm
Bradycardia is normal in people who are….
aerobically trained athletes and sleeping
Bradycardia =
decreased cardiac output
S/S bradycardia
- hypotension
- pale, cool skin
- weakness
- angina
- dizziness
- confusion
- SOB
Sinus tachycardia
101-200 bpm
If unable to measure something, document as…
non discernible or unable to assess (UTA)
Treatment for bradycardia
Atropine
Normal causes of tachycardia
- exercise
- pain
- hypovolemia
- fever
Bad causes of tachycardia
- MI
- Heart failure
sawtooth-shaped waves on EKG
atrial flutter
Single ectopic focus =
irritable
What is used to stop or rest irritable behavior in atrial flutter?
synchronized cardioversion
What does a single ectopic focus represent?
Atrial flutter
True or False:
EKG will show P wave during atrial flutter
FALSE
EKG will NOT show P wave during atrial flutter
Treatments for atrial flutter
- synchronized cardioversion
- calcium channel blockers or beta blockers
- antidysrhythmias (amiodarone)
- coumadin
What effect does calcium channel blockers or beta blockers have on the heart?
decrease heart rate
What is the most common dysrhythmia?
Atrial fibrilation
True or False
Atrial fibrilation has just 2 ectopic focus spots
False.
Atrial fibrilation has mutiple ecoptic focus spots.
What does atrial fibrilation look like on an EKG?
bunch of squiggly lines
If pt has been in a fib for >48 hours, warfarin is recommended for ___ _____ before cardioversion and for ___ _____ after successful cardioversion.
3-4 weeks
4-6 weeks
Treatment for atrial fibrilation
- synchronized cardioversion (depending on when a fib started)
- Dig, beta blockers, calcium channel blockers
- Coumadin
What is a premature ventricular contraction (PVC)?
- contraction in ectopic focus of ventricle
- early and wide QRS complex
What should you do FIRST with a PVC?
Check vital signs
Multifocal PVC
different spots
Unifocal PVC
one spot
Ventricular bigeminy
every other
Ventricular trigeminy
every 2
Couplet
2 in a row
Ventricular tachycardia
3 or more in a row
Low potassium (K) =
irritability to heart, especially ventricles
R on T
the heart isn’t fully relaxing during T wave on EKG strip.
What can R on T lead to?
lethal dysrhythmias
Treatment for PVCs
(based on cause)
- O2
- electrolyte replacement
- beta blockers, antidysrhythmias, lidocaine
Monomorphic ventricular tachycardia
1 focal point, same shape
Polymorphic ventricular tachycardia
Different shape
2 types of ventricular tachycardia
stable-with pulse
unstable-no pulse