Question 1

With atrial fibrillation the PR intervals are:

Accepted Answer

A)  absent. 
B)  shorter than normal. 
C)  prolonged. 
D)  progressively longer in duration. A

Question 2

The PR intervals are not measurable in:

Accepted Answer

A)  wandering atrial pacemaker. 
B)  atrial flutter. 
C)  2nd - degree AV heart block, Type I. 
D)  premature atrial complexes. B

Question 3

The most common cause of longer than normal PR intervals is:

Accepted Answer

A)  1st-degree AV heart block. 
B)  Premature junctional complexes. 
C)  Idioventricular rhythm. 
D)  2nd-degree AV heart block. A

Question 4

With 2nd-degree AV heart block, Type II, the PR intervals associated with the P waves which are followed by a QRS complex will be:

Accepted Answer

A)  shorter than normal. 
B)  constant. 
C)  variable. 
D)  constantly changing.

Question 5

With 3rd-degree AV heart block the PR intervals are:

Accepted Answer

A)  prolonged. 
B)  shorter than normal. 
C)  absent. 
D)  progressively longer in duration.

Question 6

1st-degree AV heart block can occur with any rhythm originating in the SA node, such as sinus rhythm, bradycardia, or tachycardia.

Accepted Answer

A) True 
 B)False

Question 7

With atrial tachycardia the P'R interval can be shorter than normal if the ectopic site is closer to the AV node.

Accepted Answer

A) True 
 B)False

Question 8

The PR interval is the distance from the beginning of the ________ to the beginning of the__________.

Accepted Answer

A)  P wave, Q wave 
B)  P wave, S wave 
C)  R wave, T wave. 
D)  PR segment, Q wave.

Question 9

Shorter than normal PR intervals may be seen in:

Accepted Answer

A)  sinus dysrhythmia. 
B)  premature atrial complexes that arise in the upper or middle right atrium. 
C)  junctional escape rhythm. 
D)  sinus tachycardia.

Question 10

The P'R intervals may vary from beat to beat in:

Accepted Answer

A)  sinus dysrhythmia. 
B)  junctional escape. 
C)  wandering atrial pacemaker. 
D)  3rd - degree AV block.

Question 11

PR intervals are considered normal if they are:

Accepted Answer

A)  shorter than 0.12 seconds. 
B)  consistently the same duration. 
C)  vary in duration. 
D)  longer than 0.20 seconds.

Question 12

When a P' follows the QRS complex the PR interval is referred to as the:

Accepted Answer

A)  P'R interval 
B)  P double R' interval 
C)  RP' interval 
D)  PR' interval

Question 13

A PR interval of greater than 0.20 seconds indicates:

Accepted Answer

A)  an intermittent blocking of the impulse as it passes through the AV node. 
B)  an increased rate of impulse discharge from the AV junction. 
C)  a pacemaker site which is either in or close to the AV junction. 
D)  a delay in conduction of the impulse between the SA node and the ventricles.

Question 14

The PR intervals get progressively longer in:

Accepted Answer

A)  sinus dysrhythmia. 
B)  2nd - degree AV heart block, Type I. 
C)  1st - degree AV heart block. 
D)  3rd - degree AV heart block.

Question 15

A PR interval of less than 0.12 seconds indicates:

Accepted Answer

A)  an intermittent blocking of the impulse as it passes through the AV node. 
B)  an increased rate of impulse discharge from the SA node. 
C)  a pacemaker site which is either in or close to the AV junction. 
D)  a delay in conduction of the impulse between the SA node and the ventricles.

Question 16

Preexcitation:

Accepted Answer

A)  leads to a delayed depolarization of the ventricles. 
B)  occurs when an impulse arises from a supraventricular site and travels through the AV node to the ventricles more quickly than normal. 
C)  leads to a longer than normal PR interval. 
D)  produces a characteristically abnormal slurring at the onset of the QRS complex and a short PR interval.

Question 17

You have determined the heart rate and regularity and examined the P waves and QRS complexes. The next logical step of analyzing an ECG rhythm is to:

Accepted Answer

A)  determine the QT interval. 
B)  evaluate the PR intervals. 
C)  examine the T waves. 
D)  examine the ST segments.

Question 18

The PR interval is normally ____ to ____ seconds in duration.

Accepted Answer

A)  0.06, 0.12 
B)  0.10, 0.12 
C)  0.12, 0.16 
D)  0.12, 0.20

Question 19

The PR interval denotes depolarization of the heart from the SA node through the atria, AV node, and His-Purkinje system.

Accepted Answer

A) True 
 B)False

Question 20

A normal PR interval:

Accepted Answer

A)  is usually present with all sinus and junctional dysrhythmias. 
B)  indicates the impulse originated from the AV junction (or close to it) and traveled through the atria and AV node in a regular and unobstructed course. 
C)  consists of the P wave and a flat line. 
D)  is seen with wandering atrial pacemaker and multifocal atrial tachycardia.

Exam 8: PR Intervals

With atrial fibrillation the PR intervals are:

The PR intervals are not measurable in:

The most common cause of longer than normal PR intervals is:

With 2nd-degree AV heart block, Type II, the PR intervals associated with the P waves which are followed by a QRS complex will be:

With 3rd-degree AV heart block the PR intervals are:

1st-degree AV heart block can occur with any rhythm originating in the SA node, such as sinus rhythm, bradycardia, or tachycardia.

With atrial tachycardia the P'R interval can be shorter than normal if the ectopic site is closer to the AV node.

The PR interval is the distance from the beginning of the to the beginning of the__.

Shorter than normal PR intervals may be seen in:

The P'R intervals may vary from beat to beat in:

PR intervals are considered normal if they are:

When a P' follows the QRS complex the PR interval is referred to as the:

A PR interval of greater than 0.20 seconds indicates:

The PR intervals get progressively longer in:

A PR interval of less than 0.12 seconds indicates:

Preexcitation:

You have determined the heart rate and regularity and examined the P waves and QRS complexes. The next logical step of analyzing an ECG rhythm is to:

The PR interval is normally to seconds in duration.

The PR interval denotes depolarization of the heart from the SA node through the atria, AV node, and His-Purkinje system.

A normal PR interval: