Third Degree AV Block

Question 1

What is the rhythm of a third degree AV block

Answer 1

1. Atrial regular
2. ventricular regular

Question 2

What is the rate of a third degree AV block

Answer 2

1. Atrial: underlying rhythm
2. 20-40 or less (ventricular pacing), 40-60 (paced by junction)

Question 3

What are the P-Wave characteristics of a third degree AV block

Answer 3

1. Sinus P waves no consistent relation to the QRS complexes
2. P waves may be hidden in the QRS complexes or T waves

Question 4

What is the PR duration of a third degree AV block

Answer 4

Varies

Question 5

What is the QRS duration of a third degree AV block

Answer 5

1. Block at AV node or bundle of His (normal)
2. Block at level of bundle branches (wide)

Question 6

What is the common cause of a 3 degree heart block?

Answer 6

1. Coronary ischemia and MI

Question 7

What are the temporary causes of 3 degree heart block?

Answer 7

1. Hyperkalemia
2. Inferior wall MI
3. Ischemic heart disease

Question 8

What is the treatment for a 3 degree Av block?

Answer 8

1. Transcutaneous pacing

Question 9

What is associated with a 3 degree heart block?

Answer 9

1. Stokes- Adams Attacks
   *fainting spells associated