AV Heart Blocks

Question 0

2˚ Heart Block Type I (Wenckbach)

Answer 0

Intrinsic Rate- Usually normal to slow
Regularity- Irregular
P Wave- Present (married except at dropped QRS (every 3rd beat)
P:QRS ratio- N:N (2:1,3:2,4:3 sec.)
PR Interval- Widening (example 0.16, 0.24 , 0.28sec.)
QRS Width- Normal to Wide

Question 1

1˚ Heart Block

Answer 1

Intrinsic Rate- Usually normal to slow 
Regularity- Regular
P Wave- Present
P:QRS ratio- 1:1
PR Interval- >0.20 Sec.
QRS Width- Normal or wide

Question 2

2˚ Heart Block Type II

Answer 2

Intrinsic Rate- Usually normal to slow
Regularity- Irregular
P Wave- Present
P:QRS ratio- Variable (can drop more than 1 QRS complex)
PR Interval- Normal or Wide when conducting (same & consistant)
QRS Width- Normal or wide

Question 3

3˚ Heart Block

Answer 3

Intrinsic Rate- A) Normal V) Normal to slow
Regularity- Regular
P Wave- Present
P:QRS ratio- Not associated
PR Interval- None - Non associated (gets narrower)
QRS Width- Normal or wide (origin dependent)