WPW

Question 1

What does it mean in terms of accessory pathways to have WPW?

Answer 1

when the accessory pathway can also conduct in the direction of atria to ventricles

Question 2

what are the features of the accessory pathway?

Answer 2

bypasses AV node, pre-exciting the ventricular myocardium
-pathway is capable of conducting anterograde (from atria to ventricles)

Question 3

how does WPW present on ECG?

Answer 3

-short PR
-delta wave
-paroxysmal tachycardia

Question 4

what can result from WPW?

Answer 4

AVRT and AF

Question 5

how is the accessory pathway created?

Answer 5

Usually in fetal development, atria becomes electrically isolated from the ventricles.
Incomplete separation leads to accessory pathway

Question 6

where is the common site for the accessory pathway?

Answer 6

Left free wall of heart

Question 7

who is WPW more common in?

Answer 7

younger people. with age, fibrosis can develop in AV groove and block accessory pathway

Question 8

what is suggested when tachycardia doesn’t occur?

Answer 8

it is termed ventricular pre-excitation, not WPW

Question 9

what causes the short PR in WPW?

Answer 9

ventricular activation is solely due to accessory pathway conduction which is fast (in SR, it is also due to AV conduction which is slower)

Question 10

what causes the broad ventricular complex and delta wave?

Answer 10

accessory pathway isnt connected to His- Purkinje system and so the rate of early ventricular activation is slow

Question 11

how is WPW divided into type A and type B?

Answer 11

depending on polarity of ventricular complex in V1

Question 12

what determines type A?

Answer 12

positive complex in V1

Question 13

what determines type B?

Answer 13

negative complex in V1

Question 14

what is type A caused by?

Answer 14

left sided accessory pathway (positive delta wave in V1)

Question 15

what is type B caused by?

Answer 15

not necessarily right sided

Question 16

what are the features of a posteroseptal pathway?

Answer 16

negative delta wave in II and aVF and positive in V2 and 3

Question 17

what are the features of a free wall pathway?

Answer 17

positive wave in II and III and negative in V1

Question 18

how does WPW lead to AF?

Answer 18

provided an extra pathway to conduct to ventricles, some impulses go down this pathway but some will be normal via AV node

Question 19

what does the AF ECG look like from WPW?

Answer 19

totally irregular ventricular response characteristic of AF (some normal complexes, some delta)

Question 20

what are the consequences of AF from WPW?

Answer 20

heart failure or shock

Question 21

what kind of accessory pathway results in lower risk of sudden cardiac death?

Answer 21

Intermittent accessory pathway conduction

Question 22

what is the treatment for symptomatic WPW?

Answer 22

Radiofrequency ablation if drugs are ineffective or cant be tolerated

Question 23

what is the treatment for asymptomatic WPW?

Answer 23

ablation considered for those that would result for employment or insurance difficulties

Question 24

treatment for AF in WPW?

Answer 24

drugs such as digoxin and verapamil

Question 25

danger with digoxin and verapamil?

Answer 25

can accelerate arrhythmia

Question 26

drugs that slow down conduction in accessory pathway?

Answer 26

sotalol, flecainide, disopyramide, amiodarone

Question 27

what is 'T wave memory'?

Answer 27

T wave continues in same direction as QRS in lead that occurred as pre-excited beats

Question 28

what is seen with T wave memory?

Answer 28

Deep T wave inversions in inferior leads of non pr-excited beats