AVRT / FLUTTER / SVT

Question 1

What are the 4 types of bypass tract in AVRT

Answer 1

1 - AV Bypass Tract
2 - Compact AVN
3 - Atrium to BB - AKA Mahaim
4 - His Purkinje

Question 2

What is the orthodromic VA conduction time of AVRT

Answer 2

> 80ms

Question 3

Give 5 differential diagnosis of SVT

Answer 3

1 - AVRT
2 - AVNRT
3 - A Flutter
4 - Ectopic A-Tachy
5 - Junctional / His Tachy
6 - Sinus Node Re-entrant Tachy

Question 4

Is AVRT micro or macro re-entry

Answer 4

MACRO

AVNRT is micro

Question 5

If conduction occurs in both directions, whats it called

Answer 5

Overt / Manifest

Question 6

If conduction is VA only, whats is called

Answer 6

Concealed

Question 7

Whats the incidence of WPW

Answer 7

3/2000

Question 8

What is an ECG hallmark of WPW during antegrade conduction

Answer 8

Delta wave

Question 9

What is a delta wave

Answer 9

Slowed conduction through myocadial tissue which attach to the accessory pathway.

Once normal conduction catches up, the QRS narrows

Question 10

What does a latent pathway possess

Answer 10

Slow conduction properties

Question 11

How does a latent pathway appear on ECG

Answer 11

Looks normal on ECG

Question 12

What percentages of WPW are Right and Left

Answer 12

60-70% are Left sided

20% are Right sided

Question 13

If the delta wave is + in V1 and V2, which side is the AP

Answer 13

+ in both = Left sided

Question 14

If the delta wave is - in V1 and V2, which side is the AP

Answer 14

• in both = Right sided

Question 15

If the delta wave is - in V1 and + in V2, which side is the AP

Answer 15

• in V1 and + in V2 = Septal

Question 16

Do pathways have decremental conduction proporties

Answer 16

No - they’re all or nothing

Question 17

What does the HV interval look like in WPW

Answer 17

Abnormally short

Question 18

What does the AV interval look like in WPW

Answer 18

Normal but very early

Question 19

Is orthodromic clockwise or anticlockwise

Answer 19

ANTIclockwise

Question 20

Is Antidromic clockwise or anticlockwise

Answer 20

CLOCKWISE

Question 21

Which is more common Orthodromic or Antidromic AVRT

Answer 21

Orthodromic is common / Antidromic is rare

Question 22

Which direction of AVRT give narrow complex QRS

Answer 22

Orthodromic (Anticlockwise) gives narrow QRS

Question 23

Which direction of AVRT gives broad complex QRS

Answer 23

Antidromic (Clockwise) gives broad QRS

Question 24

When ablating an Accessory pathway, what signal do you look for

Answer 24

Earliest V signal, pre-delta wave

Question 25

Should you ablate during tachy? Why?

Answer 25

No - Sudden termination of tachy dislodges the catheter and may result in damage to the surrounding tissue

Question 26

Does VA time change during ablation? What happens and why?

Answer 26

Yes - It slowly lengthens until it blocks completely. Lengthening is a good sign for ablation as it signifies local tissue damage

Question 27

Why is AF a problem in WPW

Answer 27

Due to a lack of decremental properties - the AF will be conducted 1:1. Such a quick V rate can lead to VF

Question 28

AF with WPW is called

Answer 28

Pre-excited AF

Question 29

Why is AF without WPW not as big of a problem

Answer 29

The AV node decrements and acts like a gatekeeper for fast rhythms - Thus V rate remains low and stable.

Question 30

Is Flutter a micro or macro re-entry tachycardia

Answer 30

Macro around the RA

Question 31

Flutter in an anticlockwise direction is

Answer 31

Typical

Question 32

Typical flutter accounts for what percentage of all Flutter

Answer 32

90%

Question 33

Reverse typical flutter flows in which direction

Answer 33

Clockwise

Question 34

Which direction of flutter is Isthmus dependant

Answer 34

Typical

Question 35

Reverse typical flutter flows around which structure

Answer 35

Tricuspid valve annulus

Question 36

What rate is flutter

Answer 36

300bpm (240-350bpm)

Question 37

P-waves are negative in INF leads / Positive in V1 - what direction is this?

Answer 37

Typical

Question 38

P-waves are positive in INF leads / Negative in V1 - what direction is this

Answer 38

Reverse Typical