BBB

Question 1

General criteria for BBB? (2)

Answer 1

1) QRS always wide

2) 2° ST/T ∆s (opp direction of QRS)

Question 2

What leads will show blocks?

Answer 2

I, V1, V6

Question 3

LBBB seen in what leads?

Answer 3

I and V1-6

Question 4

LBBB criteria: Lead I? (3)

V1-2? (3)

V3-5? (1)

V6? (2)

Answer 4

Lead I:

1) Wide, slurred R (no acute angles)
2) ST depression
3) Absent Q

V1-2:

1) Wide, negative rS or QS
2) ST seg elevation
3) Upright T

V3-5:
Loss of R-wave progression (stays - or flips + in 5)

V6:

1) Totally positive (only lead upright)
2) Absent Q

Question 5

RBBB seen in what leads?

Answer 5

I, V6, (P) V1-2

Question 6

RBBB criteria: Lead I? (3)

V1-2? (1)

V6? (1)

Answer 6

Lead I:

1) Small Q
2) Narrow R
3) Wide, slurred S

V1-2:
Positive rSR or QR if septum involved

V6:
Positive qRS