Question 1

In 2:1 AV block,_____.
A) the atrial rhythm (P-P interval)is regular
B) the ventricular rhythm (R-R interval)is irregular
C) the PR interval lengthens until a P wave appears with no QRS complex
D) there is no PR interval because the atria and ventricles beat independently of each other

Accepted Answer

Second-degree 2:1 AV block is characterized by P waves that are normal in size and shape,but every other P wave is not followed by a QRS.The atrial rate is twice the ventricular rate.

Question 2

Complete the following ECG criteria for third-degree AV block:
 Rhythm__________________________
Rate___________________________________
P waves__________________________
PR interval_________________________________
QRS duration______________________________

Accepted Answer

\(\begin{array}{|l|l|}
\hline \text { Rhythm } & \begin{array}{l}
\text { Ventricular regular; atrial regular (Ps plot through); no relationship } \
\text { between the atrial and ventricular rhythms (i.e., AV dissociation is } \
\text { present). }
\end{array} \
\hline \text { Rate } & \begin{array}{l}
\text { The ventricular rate is determined by the origin of the escape rhythm; } \
\text { the atrial rate is greater than (and independent of) the ventricular rate; } \
\text { ventricular rate is determined by the origin of the escape rhythm. }
\end{array} \
\hline \text { P waves } & \begin{array}{l}
\text { Normal in size and shape; some P waves are not followed by a QRS } \
\text { complex (i.e., more Ps than QRSs). }
\end{array} \
\hline \text { PR interval } & \begin{array}{l}
\text { None. The atria and the ventricles beat independently of each other; } \
\text { therefore there is no true PR interval. }
\end{array} \
\hline \text { QRS duration } & \begin{array}{l}
\text { Narrow or wide, depending on the location of the escape pacemaker } \
\text { and the condition of the intraventricular conduction system. }
\end{array} \
\hline
\end{array}\)

Question 3

Second-degree AV block type I is characterized by _____ intervals.
A) irregular P to P
B) regular R to R
C) regular P to P intervals and irregular R to R
D) irregular P to P intervals and irregular R to R

Accepted Answer

Second-degree AV block type I is characterized by an irregular ventricular rhythm (i.e.,irregular R to R intervals),more P waves than QRS complexes,and P waves that occur regularly (i.e.,regular P to P intervals).

Question 4

Second-degree AV block type II is characterized by _____ intervals.
A) irregular P to P
B) irregular R to R
C) regular P to P intervals and regular R to R
D) irregular P to P intervals and irregular R to R

Accepted Answer

With second-degree AV block type II the ventricular rhythm is irregular.There are more P waves than QRS complexes and the P-P interval is regular.P waves are normal in size and shape,but some P waves are not followed by a QRS complex.The PR interval may be within normal limits or prolonged,but it is constant for the conducted beats; the PR intervals before and after a blocked P wave are constant.

Question 5

In second-degree AV block type I,the PR interval _____.
A) shortens
B) is absent
C) is inconstant
D) remains constant

Accepted Answer

In second-degree AV block type I,the PR interval is inconstant and the PR interval after a nonconducted P wave is shorter than the interval preceding the nonconducted beat.
Although progressive lengthening is a phrase that was used for many years to describe the behavior of the PR intervals associated with second-degree AV block type I,use of this terminology is no longer recommended; rather,the term inconstant or generally progressive PR intervals is recommended.Use of the term inconstant or generally progressive PR intervals is important because many type I AV blocks are atypical,missing one or more of the features of the classic Wenckebach phenomenon.For example,the second conducted PR interval after a blocked impulse may fail to show the greatest increase in length; instead,the PR interval may actually shorten and then lengthen in the middle of a grouped beating pattern.Alternately,the duration of the PR intervals may show no obvious change in the middle or for a few beats just before the end of a group.

Question 6

The ventricular rhythm is regular in second-degree AV block type I.

Accepted Answer

With second-degree AV block type I,the ventricular rhythm is irregular.The atrial rate is regular (i.e.,Ps plot through on time).Grouped beating may be present.

Question 7

Complete the following ECG criteria for second-degree AV block type I:
 Rhythm__________________________
Rate___________________________________
P waves__________________________
PR interval_________________________________
QRS duration______________________________

Accepted Answer

The answer of Complete the following ECG criteria for second-degree...

Question 8

A 2:1 AV block is characterized by _____ intervals.
A) irregular P to P
B) irregular R to R
C) regular P to P intervals and regular R to R
D) irregular P to P intervals and regular R to R

Accepted Answer

Second-degree 2:1 AV block is characterized by regular P-P and R-R intervals.P waves are normal in size and shape,but every other P wave is not followed by a QRS.The atrial rate is twice the ventricular rate.

Question 9

Indicate the ECG criteria for the following dysrhythmias:
 
$\begin{array}{lccc}
 & \text {  Third-Degree AV Block } & \text {  2:1 AV Block } \
 \text { Ventricular  }  \
 \text {  Rhythm } & ----------& ---------- \
 \text { PR interval  } & ----------& ---------- \
 \text {  QRS width } & ----------& ---------- \
\end{array}$

Accepted Answer

The answer of Indicate the ECG criteria for the following...

Question 10

An ECG rhythm strip shows a regular ventricular rhythm at a rate of 30 beats/min,more P waves than QRS complexes (the P waves occur regularly),a variable PR interval,and a QRS duration of 0.14 seconds.This rhythm is _____.
A) 2:1 AV block
B) third-degree AV block
C) second-degree AV block type I
D) second-degree AV block type II

Accepted Answer

With a third-degree block,the ventricular and atrial rhythms are regular; however,AV dissociation is present.The ventricular rate is determined by the origin of the escape rhythm.Based on the description provided (i.e.,a QRS duration of 0.14 seconds and a ventricular rate of 30 beats/min),the escape pacemaker is probably ventricular in origin.P waves are normal in size and shape,but some P waves are not followed by a QRS complex.There is no true PR interval because the atria and the ventricles beat independently of each other.The QRS may be narrow or wide,depending on the location of the escape pacemaker and the condition of the intraventricular conduction system.

Question 11

In third-degree AV block,_____.
A) the atrial rhythm (P-P interval)is irregular
B) the ventricular rhythm (R-R interval)is irregular
C) there is no PR interval because the atria and ventricles beat independently of each other
D) the PR interval after a nonconducted P wave is shorter than the interval preceding the nonconducted beat

Accepted Answer

In third-degree atrioventricular (AV)block,both the atrial and ventricular rhythms are regular,but the atria and ventricles beat independently; therefore the P waves that are present are unrelated to the QRS complexes (i.e.,AV dissociation exists).

Question 12

A _____ bundle branch block produces a RSR pattern in lead V?.

Accepted Answer

The answer of A _____ bundle branch block produces a...

Question 13

In 2:1 AV block,the PR interval _____.
A) shortens
B) lengthens
C) is absent
D) remains constant

Accepted Answer

Second-degree 2:1 AV block is characterized by P waves that are normal in size and shape,but every other P wave is not followed by a QRS.The atrial rate is twice the ventricular rate.The PR interval for the conducted beats is constant.

Question 14

Most of the bundle branch tissue is supplied by the _____ coronary artery.
A) right
B) left

Accepted Answer

Most of the bundle branch tissue is supplied by a branch of the left coronary artery.

Question 15

In second-degree and third-degree AV blocks,_____.
A) P waves occur regularly
B) every other P wave is dropped
C) P waves are periodically dropped
D) there are more QRS complexes than P waves

Accepted Answer

In second-degree and third-degree AV blocks,there are more P waves than QRS complexes and the P waves occur regularly.

Question 16

A _____ bundle branch block produces a QS pattern in lead V?.

Accepted Answer

The answer of A _____ bundle branch block produces a...

Question 17

The QRS complex associated with a third-degree AV block is always wide.

Accepted Answer

The site of block in a third-degree AV block may be the AV node or,more commonly,the bundle of His or the bundle branches.A secondary pacemaker (either junctional or ventricular)stimulates the ventricles; therefore the QRS may be narrow or wide,depending on the location of the escape pacemaker and the condition of the intraventricular conduction system.

Question 18

Complete the following ECG criteria for 2:1 AV block:
 Rhythm__________________________
Rate___________________________________
P waves__________________________
PR interval_________________________________
QRS duration______________________________

Accepted Answer

The answer of Complete the following ECG criteria for 2:1...

Question 19

The PR interval of a first-degree AV block _____.
A) is constant and less than 0.12 seconds in duration
B) is constant and more than 0.20 seconds in duration
C) is generally progressive until a P wave appears without a QRS complex
D) gradually decreases in duration until a P wave appears without a QRS complex

Accepted Answer

A first-degree AV block is present when there is a 1:1 relationship between P waves and QRS complexes and the PR interval is prolonged (i.e.,more than 0.20 seconds)and constant.

Question 20

Complete the following ECG criteria for second-degree AV block type II:
 Rhythm__________________________
Rate___________________________________
P waves__________________________
PR interval_________________________________
QRS duration______________________________

Accepted Answer

The answer of Complete the following ECG criteria for second-degree...

Quiz 7: Heart Blocks

In 2:1 AV block,_____.

Complete the following ECG criteria for third-degree AV block: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

Second-degree AV block type I is characterized by _____ intervals.

Second-degree AV block type II is characterized by _____ intervals.

In second-degree AV block type I,the PR interval _____.

The ventricular rhythm is regular in second-degree AV block type I.

Complete the following ECG criteria for second-degree AV block type I: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

A 2:1 AV block is characterized by _____ intervals.

An ECG rhythm strip shows a regular ventricular rhythm at a rate of 30 beats/min,more P waves than QRS complexes (the P waves occur regularly) ,a variable PR interval,and a QRS duration of 0.14 seconds.This rhythm is _____.

In third-degree AV block,_____.

A _____ bundle branch block produces a RSR pattern in lead V?.

In 2:1 AV block,the PR interval _____.

Most of the bundle branch tissue is supplied by the _____ coronary artery.

In second-degree and third-degree AV blocks,_____.

A _____ bundle branch block produces a QS pattern in lead V?.

The QRS complex associated with a third-degree AV block is always wide.

Complete the following ECG criteria for 2:1 AV block: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

The PR interval of a first-degree AV block _____.

Complete the following ECG criteria for second-degree AV block type II: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

Quiz 7: Heart Blocks

In 2:1 AV block,_____.

Complete the following ECG criteria for third-degree AV block: Rhythm__________________________ Rate___________________________________ P waves__________________________ PR interval_________________________________ QRS duration______________________________

Second-degree AV block type I is characterized by _____ intervals.

Second-degree AV block type II is characterized by _____ intervals.

In second-degree AV block type I,the PR interval _____.

The ventricular rhythm is regular in second-degree AV block type I.

Complete the following ECG criteria for second-degree AV block type I: Rhythm__________________________ Rate___________________________________ P waves__________________________ PR interval_________________________________ QRS duration______________________________

A 2:1 AV block is characterized by _____ intervals.

An ECG rhythm strip shows a regular ventricular rhythm at a rate of 30 beats/min,more P waves than QRS complexes (the P waves occur regularly) ,a variable PR interval,and a QRS duration of 0.14 seconds.This rhythm is _____.

In third-degree AV block,_____.

A _____ bundle branch block produces a RSR pattern in lead V?.

In 2:1 AV block,the PR interval _____.

Most of the bundle branch tissue is supplied by the _____ coronary artery.

In second-degree and third-degree AV blocks,_____.

A _____ bundle branch block produces a QS pattern in lead V?.

The QRS complex associated with a third-degree AV block is always wide.

Complete the following ECG criteria for 2:1 AV block: Rhythm__________________________ Rate___________________________________ P waves__________________________ PR interval_________________________________ QRS duration______________________________

The PR interval of a first-degree AV block _____.

Complete the following ECG criteria for second-degree AV block type II: Rhythm__________________________ Rate___________________________________ P waves__________________________ PR interval_________________________________ QRS duration______________________________

Complete the following ECG criteria for third-degree AV block: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

Complete the following ECG criteria for second-degree AV block type I: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

Complete the following ECG criteria for 2:1 AV block: Rhythm________ Rate_ P waves PR interval_ QRS duration____________

Complete the following ECG criteria for second-degree AV block type II: Rhythm________ Rate_ P waves PR interval_ QRS duration____________