Arrhythmias Flashcards
What is a PAC
premature atrial contraction
Where does a PAC originate
Either atrial tissue or AV node
If a PAC originates in the AV node, what is it known as
Junctional
What are causes of PAC
idiopathic
Toxins
ACS
COPD
Atrial myopathy
What are PVCs
Premature ventricular contractions
Where do PVCs originate
Ventricular myocardium
What are some causes of PVCs
Reentry from cardiac scarring
Ischemia
Catecholamine surge
Electrolyte abnormality
What is it called when there are multiple PVCs occurring but from different areas of the myocardium
multiform PVC
What is Bigeminy
Every 2 beats there is a PVC
What is trigemini
2 normal beats and then a PVC
What are the subtypes of PVCs
Bigeminy
Trigeminy
Quadreminy
How are PVCs classified
Morphology
Frequency
Symptomatic vs. asymptomatic
exertional or not
What is a block
Delay in conduction along the ventricular pathway
What is a first degree AV block
a delay in transmission from atria to ventricles
What will first degree block look like on EKG
Prolonged PR interval
What can cause first degree AV block
increased vagal tone
Fibrosis / scarring
Idiopathic
Familial disease
What is second degree AV block
Intermittent Av conduction
What are the two subtypes of second degree AV block
Mobitz type 1
Mobitz type 2
What is mobitz type 1
Wenckebach
*Progressive prolongation until beat drop
-First PR is normal
What is Mobitz type 2
PR is maintained but will occasionally not conduct through the ventricles
What is the cause of second degree AV block
MI near the conducting system
cardiomyopathy
myocarditis
endocarditis (abscess)
what is third degree Av block
complete heart block, no atrial impulses reach the ventricle
- atria and ventricles firing separately
What is the cause of third degree AV heart block
Myocardial ischemia
cardiomyopathy
myocarditis
myxedema
iatrogenic
hypervagotonia
How may a patient present with third degree heart block
lightheadedness
palpitations
syncope
weakness
fatigue
chest pain (diminished O2)
What is a bundle branch block
disruption of electrical conduction down one of the bundle branches coming off the bundle of his
What is a right bundle branch block associated with
increased RV hypertrophy
PE
MI
inflammation
iatrogenic
What is a left bundle branch block associated with
endocarditis
post surgical changes
What will be seen on and EKG if someone has a LBBB
Wide QRS
What will you see on an EKG with someone who has a RBBB
Bunny ears
What are examples of narrow / regular tachyarrythmias
sinus tachy
SVT
Atrial flutter
What are examples of narrow/irregular tachyarrythmias
Multifocal atrial tachycardia
hyperkalemia
What are examples of wide regular tachyarrhythmias
polymorphic ventricular tachycardia
Vfib
What are tachyarrhythmias generally associated with
increased automaticity
increased triggering
re-entry circuit
What are the 4 questions to ask first when looking at an EKG
Regular or irregular
fast or slow
wide or narrow
P waves
What is the most common tachyarrythmia
sinus tachy
What causes sinus tachy
Norepi and epi increase automaticity in the SA node
What is paroxysmal SVT
sustained re-entry loop within the AV node
Who is PSVT most commonly seen in
Women
early 20s
no CV disease
How can you tell the difference between PSVT and sinus tachy
SVT will NOT have fluctuations
SVT has no PR interval
What is the most commonly treated dysrhythmia
Afib
What will afib look like on an EKG
irregularly irregular rhythm with a narrow QRS complex
What is the most common source of afib
pulmonary veins
What determines your heart rate
ventricles
What is the cause of afib
**typically a secondary disease process
-ischemic heart disease
-valvular heart disease
-HTN
-congestive cardiomyopathy
What are causes of new onset afib
pulmonary disease (COPD/PE)
Ischemia (ACS)
Mitral stenosis
Anemia
Thyrotoxicosis
Endocarditis
sepsis
What are the 3 types of afib
paroxysmal
persistent
permanent
What is paroxysmal afib
lasts less that 7 days with spontaneous conversion
What is persistent afib
over 7 days long or requires cardio version
What is permanent afib
long standing - will always be there
What lead is best to look at for afib
V1
What symptoms are associated with afib
SOB
Palpitations
Chest pain
nausea
lightheadedness
fatigue
What is atrial flutter
atrial tachycardia with a single reentrant circuit
What will atrial flutter look like on an EKG
sawtooth pattern
*single morphology P waves
where in the heart does aflutter typically occur
above the tricuspid valve and inferior to the vena cava orifice
What is vtach often associated with
previous MI
What is the number 1 reason for vtach and sudden cardiac death
prolonged QT
What are some causes of vtach
channelopathies
cardiomyopathy
myocarditis
CAD
valvular disease
What is Torsades de pointes
Polymorphic VT
What is the cause of torsades
Electrolyte abnormality
* decreased magnesium
How do you treat someone with torsades
IV infusion of magnesium
What is vfib
chaotic depolarization of the ventricular myocardium
*no cardiac output
What can put someone at higher risk for vfib
scar tissue or infarcted area will have increased automaticity
high heart rate can induce
what causes bradyarrhythmias
vagus nerve stimulation
-endurance athletes
-inferior wall MI
Medications that slow AV conduction
Metabolic changes
Electrolye abnormality
Brain herniation
What is Cushings triad
bradycardia
respiratory change
increase bp
What is another name for tachybrady syndrome
sick sinus dysfunction
What is sick sinus syndrome
dysfunction with the SA node
What is the pathophys of sick sinus syndrome
fibrosis of SA node
medications
familial disease (channelopathy)
How can you treat sick sinus syndrome
pacemaker
medications
