Deck 19: Bundle Branch Block

Question 1

Activation of the septum produces:

A) small R waves in leads V1 and V2
B) large Q waves in V1 andV2
C) small Q waves in leads V5 and V6
D) a and c

Answer 1

a and c

Question 2

As the impulse moves through the left ventricle it produces:

A) small S waves is leads V1 and V2
B) large Q waves in V1 andV2
C) tall R waves is leads V5 and V6
D) All of these

Answer 2

tall R waves is leads V5 and V6

Question 3

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

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

Answer 3

left atrium

Question 4

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

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 5

Bundle branch block:

A) is a disorder that leads to one or both of the bundle branches conducting impulses in an accelerated manner.
B) produces a widened QRS complex and the R, R' configuration in the limb leads.
C) leads to a delay in the depolarization of the ventricle it supplies.
D) leads to right axis deviation.

Question 6

The most telling sign of bundle branch block is

A) a wide QRS complex, at least 0.12 seconds or more in duration.
B) notching of the QRS complexes.
C) more P waves than QRS complexes.
D) T waves that take an opposite direction to the R waves.

Question 7

Bundle branch block occurs only in:

A) ventricular rhythms
B) supraventricular rhythms
C) AV heart block
D) Atrial rhythms

Question 8

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

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 9

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

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

Question 10

The R' is referred to as ________ and represents delayed depolarization of the blocked ventricle.

A) R prime
B) rabbit ears
C) M shaped
D) delta wave

Question 11

Possible sites of bundle branch block include:

A) right bundle branch.
B) left anterior fascicle.
C) left posterior fascicle.
D) All of these

Question 12

RBBB occurs when conduction through the:

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 13

In RBBB, the right ventricle is depolarized via the:

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

Question 14

One indicator of RBBB is an R, R' in leads:

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

Question 15

Another indicator of RBBB is/are:

A) reciprocal late broad S waves in I, aVL , V5, and V6
B) a T wave that deflects opposite of the QRS complex in most leads
C) tall, wide, slurred R waves in I, aVL,V5, and V6
D) a & b

Question 16

LBBB occurs when conduction through the:

A) left bundle branch is blocked, cause depolarization of the left 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 17

In LBBB, the right ventricle is depolarized via the:

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

Question 18

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

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

Question 19

Incomplete bundle branch block occurs when:

A) one of the fascicles is blocked.
B) both bundle branches are blocked.
C) heart beat ceases.
D) the bundle branch conducts the impulse more slowly but it is not totally blocked.

Question 20

Indicators of incomplete bundle branch block include:

A) reciprocal late broad S waves in I, aVL , V5, and V6
B) tall, wide, slurred R waves in I, aVL,V5, and V6
C) QRS complexes having a similar appearance to bundle branch block but are no greater than 0.11 seconds in duration.
D) ST segment depression and T-wave depression.

Question 21

Hemiblocks cause:

A) axis deviation.
B) wide, notched QRS complexes.
C) biphasic QRS complexes in V1 and V2
D) very short R waves with much larger S waves in leads V5 and V6

Question 22

RBBB occurs with anterior wall MI, coronary artery disease, hypertension, scar tissue that develops after heart surgery, viral or bacterial infection of the heart muscle, and pulmonary embolism. It may also be caused by drug toxicity.

Question 23

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).

Question 24

Repolarization abnormalities are uncommon in RBBB and LBBB.

Question 25

Left anterior hemiblock results in right axis deviation.

Question 26

Bundle branch block is diagnosed by first analyzing the width of the QRS complexes.

Question 27

Bifascicular block is a conduction disturbance in which two of the three main fascicles of the His/Purkinje system are blocked.

Question 28

LBBB usually indicates underlying cardiac pathology.