Cardiology AVRT / AVNRT & VT Flashcards
What are some quick important terms to be familiar with in AVRT & AVNRT
Electrophysiology recap: what is Race?
R efreactory
A utomaticity
C onductivity
E excitbility
What is our Physiology of our AV node
Our AV node has two pathways in which our action potentials can travel down
They are our Fast and Slow pathway
How do these pathways link to AVRT & AVNRT
The fast pathway has a much faster-conducting rate. However, it also has a greater refractory period than the slow pathway.
The slow pathway take longer to conduct the signal and then has a relative shorter refractory period
What is a broad over view of SVT
IMPORTANT: What are the three physiological criteria for developing AVNRTs
- You MUST have a circut with ATLEAST 2 pathways (fast & slow)
- You have to have an area of impulse slowing or temporary blockage (slow pathway with longer refractory)
- You have to have an Ectopic beat
How does an AVNRT occur
This is because of a premature (ectopic beat) traveling down the fast pathway and the slow pathway. eventually it travels up the fast pathway and creates a circular motion (re-enterent)
What is the difference between AVRT & AVNRT
AVRT is associated with an accessory pathway. An accessory pathway is where conductive fibers can continue to propagate impulses, often by bypassing the AV node
What is the difference between Polymorphic and monomorphic VT
Monomorphic - Single shaped ‘typical VT’ Considered Vt when it is present and sustained for longer than 30 secs
Polymorphic - Multiple shapes. This can look like a mix between VT & VF The typical Polymorphic VT is Torsade’s de point.
Often associated with Long QT syndrome
The difference between Congenital long QT syndrome and Acquired Long QT syndrome
What is wolf parkinson white syndrom and how do you reconigse it
This is where you have an accessory pathway called the bundle ok kent. This bundle then can trigger earlier depolerization of the ventrilces
What is Lown-Ganong-Levine Syndrome
This is where there are more conductive fibres (james firbers) that skip the AV node
