Question 1

LBBB can be caused by anterior wall MI; hypertensive heart disease; aortic stenosis; degenerative changes of the conduction system; or thickened, stiffened, or weakened heart muscle (cardiomyopathy).

Accepted Answer

A) True 
 B)False

Question 2

The QRS complex is normally ______ seconds in duration and the mean QRS axis lies between __________.

Accepted Answer

A)  greater than 0.12, +90 $\degree$ and +180 $\degree$ 
B)  0.10 or less, 0 $\degree$ and +90 $\degree$ 
C)  less than 0.10, 0 $\degree$ and +30 $\degree$ 
D)  between 0.12 and 0.20, 0 $\degree$and +90 $\degree$

Question 3

In RBBB, the right ventricle is depolarized via the:

Accepted Answer

A)  right bundle branch. 
B)  ventricular apex. 
C)  left ventricle across the septum. 
D)  left posterior fascicle.

Question 4

To diagnose left bundle branch block check for wide, tall, slurred R waves in leads:

Accepted Answer

A)  V1 or V2. 
B)  V5 or V6. 
C)  V2 or V3. 
D)  V4 or V5.

Question 5

RBBB occurs when conduction through the:

Accepted Answer

A)  left bundle branch is blocked, cause depolarization of the right ventricle to be delayed. 
B)  right bundle branch is blocked, cause depolarization of the left ventricle to be delayed. 
C)  right bundle branch is blocked, cause depolarization of the right ventricle to be delayed. 
D)  left posterior fascicle is blocked, cause depolarization of the right ventricle to be delayed.

Question 6

When we see two R waves, we name them in sequential order, the:

Accepted Answer

A)  R' and R 
B)  R and R' 
C)  R' and R" 
D)  R" and R'

Question 7

In bundle branch block, QRS complexes having two peaks occur because:

Accepted Answer

A)  right and left ventricular depolarization are out of synch with one another. 
B)  the ventricles are depolarized twice with the same impulse. 
C)  the ventricles are depolarized via an accessory pathway. 
D)  septal depolarization is delayed.

Question 8

Deep S waves in V1, V2 and tall R waves during depolarization of the left ventricle represent the electrical dominance of the:

Accepted Answer

A)  septum 
B)  left ventricle 
C)  right ventricle 
D)  left atrium

Exam 19: Bundle Branch Block