Arrhythmias Flashcards
Bradycardia
<60 HR
w/ Cardiopulmonary Compromise
What is Cardiac Compromise
Cardiopulmonary Compromise = hypotension, AMS, DLOC, Shock
Primary Bradycardia
Result of congenital heart condition
Primary Bradycardia examples
Myocarditis
Cardiomyopathy
Surgical injury to the pacemaker
Congenital abnormality
Secondary Bradycardia
Result of noncardiac conditions
Secondary Bradycardia examples
Hypoxia Acidosis Hypotension Hypothermia Drug Effects
STUDY AV BLOCKS
STUDY AV BLOCKS
Narrow QRS
<0.09 seconds
Wide QRS
> 0.09 seconds
Narrow Complex Tachycardia
Sinus taachy
Supraventricular tachy
Atrial flutter
Wide Complex Tachycardia
Ventricular tachycardia
SVT
Etopic atrial focus
abnormal pacemaker sites within the heart
normally suppressed by SA node
occur in atria or ventricles
HR in ST
Infants <220 min
Chldren <180 min
ST Hx
Gradual Onset
Fever, pain, dehydration, hemorrhage
ST PE
Crackles, fever, hypovolmeia, anemia
HR in SVT
Infants >220
Children >180
SVT Hx
Abrupt onset
Infant: CHF
Child: Palpitations
SVT PE
CHF
Rales, hepatomegaly, edema
Ventricular Tachycardia
Wide QRS complex
2 Forms of VT
Monomorphic Polymorphic (Torsades de pointes)
Atropine dosage
0.02 mg/kg - May repeat dose ONCE
Minimum dose 0.1 mg
Max single dose 0.5 mg
<60 HR w/ cardiopulmonary compromise?
CPR
<60 Hr w/ cardiopulmonary compromise persisting with CPR…
Epi
Atropine
Transthoracic/Transvenous Pacing
What is increased vagal tone
Vagal Nerve
Activates parasympathetic nervous tone
Your body relaxes faster after stress
What is atropine used for
increased vagal tone
AV block
Cholinergic drug toxicity
(epi can cause ventricular arrhythmias during these circumstances)
Epi has both
alpha and beta adrenergic activity
What does Beta adrenergic do
Increases HR & cardiac contractility
What does Alpha adrenergic do
Causes vasoconstriction
The effects of epi and other catecholamines can be reduced by
acidosis and hypoxia
What is a parasympatholytic
Reduces the activity of the parasympathetic nervous system
Atropine what type of drug
parasmypatholytic (anticholinergic)
How does atropine work on the body
It accelerates sinus or atrial pacemakers and enhances AV conduction
What does cholinergic do?
Mimics acetylcholine
What is acetylcholine
Primary transmitter of nerve impulses in the parasympathetic nervous system
What can be used for tx of Mobitz I & II, and third-degree AV block?
Atropine
Atropine dose in ET
0.04 to 0.06 mg/kg
What do cholinesterase inhibitors do
Prevent the breakdown of acetylcholine or butyrylcholine
Vagal maneuvers to terminate SVT
Ice on the face for 15 to 20 seconds
Blow through a straw
Carotid sinus massage in older children
Do not apply ocular pressure - retinal injury
When are unsynchronized shocks used
For defibrillation because the cardiac arrest rhythms have no QRS
synchronized shocks are used
from SVT and VT
When does the synchronized shock hit
R wave
What happens if you don’t hit the synchronized shock
it could lead to VF because you could hit the vulnerable period of the T wave
Cardioversion dosage
Start w/ 0.5 to 1 J/Kg
inc 2 J/kg
0.5 - 1 - 2
Drug choice for tx f SVT
Adenosine
What is Adenosine dosage
RAPID IV BOLUS
- 1 mg/kg (max first 6mg)
- 2 mg/kg (max second 12mg)
Decrease the dose of Adenosine for those w/
transplanted hearts
Adenosine MOA
Blocks conduction through the AV node temporarily
Atrioventricular node reentry
Causes the heart to beat prematurely
Amiodarone Dosage
5 mg/kg loading dose over 20 - 60 minutes
Max single dose 300mg
Max 15 mg/kg a day
(Not exceed adult dose of 2.2g over 24 hours)
Why is a slower rate of Amio advised?
Because it can cause hypotension and decreased cardiac contractility
Drug that can terminate SVT that is resistant to other drugs
Procainamide
How does procainamide work?
Blocks the sodium channel
Prolongs the effective refractory period of the atria and ventricles
Procainamide dose
Infuse a loading dose of 15mg/kg over 30 - 60 mins
What drug should you not use in infants for SVT
Verapmil - CCB
Has caused refractory hypotension and cardiac arrest
