Conduction Blocks Flashcards Preview

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Flashcards in Conduction Blocks Deck (28):
1

What is a conduction block?

Any obstruction or delay of the normal pathways of electrical conduction.

2

3 types of Conduction Blocks:

Sinus node block

AV block

Bundle branch block
 

3

What type of block:

Sinus node fires normally, but wave of depolarization is blocked and not transmitted to atrial tissue.

Sinus node block

4

What type of block:

Any conduction block between the sinus node and Purkinje fibers (including AV node & His bundle).

AV block

5

What type of block:

Conduction block in one or both of the ventricular bundle branches.

Bundle branch block

6

What is a type of bundle branch block where only part of one of the bundle branches is blocked?

Fascicular block

7

What are the 3 types of AV blocks?

First Degree
Second Degree
Third Degree

8

What type of block:

 

Q image thumb

1º AV Block

9

What type of block:

 

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2º AV Block Mobitz II

10

What type of AV block is characterized by a suddenly dropped QRS?

2º AV Block Mobitz II

11

What type of block:

Q image thumb

3º AV Block

12

What type of block:

Q image thumb

1º AV Block 

13

What type of block:

 

Q image thumb

2º AV Block

14

What type of block:

 

Q image thumb

2º AV Block Mobitz II

15

What type of block:

Q image thumb

3º AV Block

16

What are the steps to identify a RBBB? (2)

Look in V1 and V2 for a R1R1 wave (basically 2 R waves)

Look in V5, V6, and Lead I for a "slurred S" wave

A image thumb
17

What type of block:

Q image thumb

RBBB

Notice 2 R waves in V1 and V2.

Notice "slurred S" wave in V5, V6, and I.

18

What are the steps to identify a LBBB? (2)

Look in V5, V6, or Lead I for a blunted positive QRS and t-wave is inverted

Look in V1-V3 for a predominantly negative QRS

19

What type of block:

 

Q image thumb

LBBB

20

What type of block:

 

Q image thumb

RBBB

21

What type of block:

 

Q image thumb

LBBB

22

What type of block:

Q image thumb

RBBB

23

What major effect does a hemiblock have on the EKG? 

axis deviation

24

What type of block:

Conduction down the left anterior fascicle is blocked and current rushes down the left posterior fascicle to the inferior surface of the heart. 

Depolarization goes from inferior to superior and right to left in direction.

Left Anterior Hemiblock

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25

What type of block:

Tall R wave in left lateral leads

Deep S waves inferiorly

Left Anterior Hemiblock

26

What type of block:

 

Q image thumb

Left Anterior Hemiblock

27

What type of block:

All of the current rushes down the left anterior fascicle and ventricle myocardial depolarization ensues superior to inferior and left to right in direction.


The axis of depolarization is down and to the right (RAD), tall R waves in inferior leads and deep S waves in left lateral leads.

Left Posterior Hemiblock

28

What type of block:

 

Q image thumb

Left Posterior Hemiblock