Atrial Flutter Flashcards
What is atrial flutter?
Atria contract at high rates ~ 300 bpm but sometimes as high as 400 bpm
The muscle contraction flowing through atria is a wave and looks like its fluttering
What is the mechanism of atrial flutter?
There is a re-entrant rhythm that starts in L/R atrium (signals in the atria that loop back on themselves), overriding the SA node and sending a constant signal that causes the atria to contract repeatedly at fast rates
What is a type 1 atrial flutter?
Typical atrial flutter - more common
Moves around the ring of the tricuspid valve (RA)
Counterclockwise direction when looking up at atrium through valve
What is type 2 flutter?
Atypical atrial flutter
Reentrant signal in R OR L atrium
Exact location less defined
Wave of depolarisation hits a bit of tissue that causes a loop of depolarisation going round and round
What can cause atrial flutter?
Underlying disease (ischameia) irritates heart cells -> altering some of their properties e.g. refactory period -> reentrant circuits develop
Or reentrant circuits can develop from a premature atrial contraction (cause of PCA unknown)
Why are the ventricles not beating as fast/at the same time as the atria flutter?
The AV node has a long refactory period meaning it has a limit to how many times it can depolarise
This means the AV node has to wait a min or 333ms to depolarise again = ventricles max ~180bpm
If atrium bpm > 180, a ratio between the No. of contraction of the atria and ventricles per min is created e.g 3:1
What does atrial flutter look like on ECG
Flutter waves instead of p wave (sawtooth shaped)
QRS complex
What is supraventricualr tachycardia?
Ventricles bpm >100 and signal originates ABOVE the ventricles
- atrial fibrillation
- atrial flutter
- ectopic (premature ventricular complexes PVCs) atrial tachyardia
What can atrial flutter lead to and why?
HEART FAILURE from prolonged tachycardia where the ventricles begin to compensate
STROKE as atria are not contracting effectively the blood stagnates forming CLOTS -> embolism in brain
Treatment for atrial flutter and why?
Anticoagulants: reduce clot formation from ineffective atria
Beta blockers and CCBs: for prolonged tachycardia
Cardio version: to let atria depolarise all at once and SA node take control again
Depending on type: radio frequency catheter ablation, tissue in isthmus destroyed so no signals can propagate from it
What symptoms can arise form faster ventricular contraction (supraventricular tachycardia)?
SOB
Chest pain
Dizziness
Nausea
