arrhythmias Flashcards
What are some sinus node disturbances
Sinus Brady
Sinus node dysfunction
Junctional Brady cardia
sinus arrest
sinus tachy
What drugs can cause bradycardia
beta blockers
calcium channel blockers
What is chronotropic incompetence
SA is not responding to stress placed on it
What is the cause of sinus exit block
an issue with transition cells
What is sinus arrest
Long pauses in between regular beats
*if longer than 3 seconds-> need a pacemaker
What is junctional bradycardia
AV node fires faster than the SA node
P waves are hidden within or after QRS
Narrow QRS
**because its originating in the AV node, it will be slow
What does an escape beat look like on an EKG
A beat that comes later than expected
What is asystole
complete absence of demonstrable electrical and mechanical cardiac activity
What is sick sinus syndrome
Sinus node dysfunction
What causes sick sinus dysfunction
fibrosis of the SA node
Medication suppression
Chronotropic incompetence
cardiorespiratory conditioning
How do you manage someone with sick sinus syndrome
Atropine (better for SA node vs junctional rhythm)
temporary pacing wire
possible pacer
What is a sinus arrhythmia
A normal cardiac cycle where you see and increase of HR on inspiration and a decrease on expiration
What causes sinus tachycardia
stimulation of the sinus node
*adrenergic response (fight or flight)
What is one of the most sensitive findings of a PE
sinus tachy
What is the first line treatment of sinus tachycardia
treat reversible causes
then consider beta blockers
What are atrial rhythm disturbances
Atrial fibrillation
atrial flutter
wandering atrial pacemaker
SVT
What is the mechanism of Aflutter
circuit of re-entrant activation (cavotricuspid isthmus)
Where does afib generally originate
transition tissue of the pulmonary vein
What is the mechanism of afib
wavelets of re-entrant activation
What is the management of afib/flutter
anticoagulate
rate control (beta blocker)
rhythm control (Na+ / K+ blocker)
What is a WAP rhythm
Wandering atrial pacemaker
rate <100bpm
polymorphic P waves
What is a MAT rhythm
Multifocal atrial tachycardia
Rate >100
Polymorphic P waves
Which patient population are at higher risk of developing MAT / WAP
Those with pulmonary disease
-COPD
What is the mechanism behind WAP / MAT
multiple atrial ectopic foci
How do you treat MAT / WAP
Oxygen levels
treat underlying causes
What are the two kinds of SVT
AVNRT (most common)
AVRT
How will someone with SVT present
Palpitations
lightheadedness
heart racing
pre syncope / syncope
If someone complains that their heart feels funny when they bend forward, what is their most likely dx
AVNRT until proven otherwise
How do you manage SVT acutely
Vagal maneuvers
Adenosine
Cardioversion
Why do vagal maneuvers help with SVT
b/c vagus nerve innervates the AV node and will slow it down
Why does Adenosine help treat SVT acutely
Adenosine blocks the AV node so the rate can get back to a regular rhythm
Which patients do you NOT want to use adenosine on
Afib and WPW
*use procainamide instead
How do you control chronic SVT
Rate control
antiarrythmics (flecainide)
ablation
What will an EKG in someone with WPW look like
There will be no PR interval
Will see a delta wave
What are the A-V junctional rhythm disturbances (heart block)
First degree
Second degree (mobitz 1&2)
Third degree
What is second degree heart block known as
Wenckebach
Which second degree heart block is more unstable
type 2
What occurs in third degree heart block
complete atrial ventricular dissociation
What causes junctional rhythm disturbances
Disease of the AV node
-lyme carditis
-congenital
-fibrosis (m/c)
-iatrogenic (TAVR)
How will someone with a junctional rhythm present
SOB
Lightheadedness
syncope
How do you manage junctional arrhythmias
Acute (HD unstable)
-Atropine / dobutamine
-temp pacer wire
Chronic
-pacer
What causes ventricular dysrhythmias
VT
torsades
VF
What is brugada’s sign
time from onset of R wave to lowest point of S wave >100ms
What is Josephson’s sign
notching near the lowest point of the S wave
What are the mechanisms of ventricular tachyarrythmias
Ischemia / infarct
drugs
toxicity
metabolic derangement
prolonged QT
How will patients present with ventricular tachyarrythmias
unconscious / pulseless
SOB
Lightheadedness
palpitations
How do you manage tachyarrythmias
Amioderone
Lidocaine
Cardioversion (if regular)
Defib (if irregular)
TdP: Mag, Mag, more Mag
What is seen on both RBBB and LBBB EKGs
wide QRS complex
What will be seen on an EKG with RBBB
Wide QRS
ST segment depression
T wave inversion
**rabbit ears in V1 or V2
**broad S wave in V6
What will be seen on an EKG in someone with a LBBB
Wide QRS
RR in V6
Dominant S wave in V1
When is Sgarbossas criteria used
A new LBBB w/ question of ACS
What generally causes BBB
Fibrosis
Ischemia / infarct
Drugs / toxicity
