EKG conduction blocks pt 1 highlights

Question 1

List 3 types of conduction blocks

Answer 1

1) Sinus nodal block
2) AV blocks
3) BBB or hemiblocks

Question 2

Define each of the following:
1) Sinus nodal exit block
2) AV blocks/ delay
3) Bundle branch blocks (BBB)/ delay

Answer 2

1) SA node fires but electrical impulse blocked from entering atrial tissue; appears on EKG as a pause (sinus arrest)
2) Block/delay between SA node and Purkinje fibers
3) Block in right and/or left bundle branches

Question 3

How are AV node blocks diagnosed?

Answer 3

By examining PR interval & relationship of P waves to the QRS

Question 4

What is characterized by a regular rhythm (PtoP & RtoR are regular) and a narrow QRS?

Answer 4

First Degree AV Block/delay

Question 5

Second Degree AV Block: Not every P wave makes it thru AV/His to cause a QRS; therefore _____________ rhythm

Answer 5

irregular

Question 6

What are 2 important points abt Mobitz type 1 (Wenckebach block = “wide PR”) 2nd degree AV blocks?

Answer 6

1) PR interval gradually prolongs (“widens”)
2) Transient and benign, rarely progresses to 3rd degree block

Question 7

What are 2 important points abt Mobitz type 2 second degree AV blocks?

Answer 7

1) Dropped beat without progressive lengthening of the PR interval
2) More serious although less common than type 1; may progress to 3rd degree heart block and a pacemaker is indicated for these patients – be ready for complete block

Question 8

Third Degree AV Block (AKA Complete Heart Block):
1) What occurs?
2) What is the Tx?

Answer 8

1) Ventricular escape beats… Regular rhythm at Ventricular pacer rate
2) Pacemaker