Deck 6: P-Waves

Question 1

The third step of analyzing an ECG rhythm should be to:

A) examine the U waves.
B) evaluate the ST segments.
C) determine QT interval.
D) examine the P waves.

Answer 1

examine the P waves.

Question 2

Characteristics of normal P waves include:

A) there is one P wave preceding each QRS complex.
B) they have an amplitude of 0.12 to 3.5 mm.
C) they are usually rounded and biphasic.
D) they have a duration of 0.12 to 0.20 seconds.

Answer 2

there is one P wave preceding each QRS complex.

Question 3

In lead II, the deflection of the P wave is characteristically:

A) negative.
B) biphasic.
C) upright.
D) negative or biphasic.

Answer 3

upright.

Question 4

Normal P waves are those that:

A) look different.
B) are inverted.
C) follow the QRS complex.
D) are rounded and upright.

Question 5

Tall and symmetrically peaked P waves may be seen with:

A) increased right atrial pressure and right atrial dilation.
B) increased left atrial pressure and left atrial dilation.
C) a delay in the movement of the electrical impulse between the right and left atria.
D) impulses that originate outside the SA node.

Question 6

Impulses that arise from outside the SA node:

A) produce P waves that look the same as the sinus P waves
B) are called P prime or P' waves.
C) are typically inverted.
D) depolarize the atria in a retrograde direction.

Question 7

If the ectopic impulse arises from the middle of the right atrium the P' wave is:

A) absent.
B) inverted.
C) less positive than one that originates from the upper-right atrium.
D) biphasic or inverted.

Question 8

Premature beats that arise from the atria or internodal pathways produce P' waves that:

A) appear the same as the other normal beats.
B) look peaked, notched, or larger than normal.
C) are tall and symmetrically peaked.
D) may be obscured or buried in the T wave of the preceding beat.

Question 9

The P' waves in tachycardia arising from the atria:

A) have a different morphology than normal P waves.
B) are buried in the T wave of the preceding beat.
C) look the same as those seen in sinus tachycardia.
D) are indiscernible.

Question 10

P' waves that continuously change in appearance indicate that the:

A) impulses are originating from one site.
B) atria are firing at a rate of between 250 and 350 beats per minute.
C) impulses are arising from different locations in the atria.
D) atria are firing in a rapid, chaotic manner.

Question 11

When the atrial waveforms appear in a saw-toothed pattern it reflects that the:

A) impulses are arising from different locations in the atria.
B) atria are firing at a rate of between 250 and 350 beats per minute.
C) a delay in the movement of the electrical impulse between the right and left atria.
D) impulse is being blocked as it travels through the bundle of His.

Question 12

When the atria fire faster than 350 beats per minute:

A) it produces a chaotic-looking baseline with no discernable P waves.
B) "F" waveforms are seen.
C) the P' waves continuously change in appearance.
D) there are more upright and round P waves than there are QRS complexes.

Question 13

Inverted P' waves occur when the:

A) atria are firing at a rate of between 250 and 350 beats per minute.
B) impulses arise from the middle of the right atrium.
C) atria are firing in a rapid, chaotic manner stimulating all parts of the atria at the same time.
D) electrical impulse originates in or near the AV junction and travels upward into the atria causing retrograde depolarization.

Question 14

P' that occur with impulses arising from or near the AV junction:

A) are round and upright.
B) are biphasic.
C) may precede, be buried in or follow the QRS complex.
D) are not followed by a QRS complex.

Question 15

When there are more P waves than QRS complexes it indicates that:

A) impulses are arising from the lower-right atrium near the AV node or in the left atrium.
B) the atria are firing so fast that not all the impulses can pass through the AV node and some are blocked.
C) impulses are initiated in the SA node or other ectopic sites in the atria but are blocked and do not reach the ventricles.
D) impulses are arising from many different locations in the atria.

Question 16

When the P waves seem to "march through" the QRS complexes it indicates:

A) a complete blockage of the AV node.
B) the atria are firing at a much faster rate than the ventricles.
C) the impulses are arising from the middle of the left atrium.
D) the atria are firing chaotically at a rate of greater than 350 beats per minute.

Question 17

Your 85 year old patient has a heart rate of 70 BPM. Analysis of the ECG reveals a slightly irregular rhythm with one P wave preceding each narrow QRS complex. The appearance of the P waves appears to change as often as from beat to beat. This is likely the result of:

A) early beats arising from the atria.
B) AV heart block.
C) an enlarged left atrium.
D) a changing pacemaker site.

Question 18

Your 72 year old patient has a heart rate of 82 BPM. Analysis of the ECG reveals a totally irregular rhythm with a chaotic appearing baseline preceding each narrow QRS complex. This is likely the result of:

A) early beats arising from the atria.
B) the atria firing at a rate in excess of 350 BPM.
C) an enlarged left atrium.
D) a changing pacemaker site.

Question 19

Your 33 year old patient has a heart rate of 150 BPM. Analysis of the ECG reveals a regular rhythm with a tall upright P wave preceding each narrow QRS complex. The P waves are partially buried in the T wave of the preceding beat. This is likely the result of:

A) early beats arising from the atria.
B) a tachycardia arising from the SA node .
C) an enlarged left atrium.
D) a changing pacemaker site.

Question 20

Your 44 year old patient has a heart rate of 94 BPM. Analysis of the ECG reveals a regular rhythm with sawtooth appearing waves preceding each narrow QRS complex. This is likely the result of:

A) early beats arising from the atria.
B) the atrial firing at a rate of between 250 and 350 BPM.
C) a changing pacemaker site.
D) AV heart block.

Question 21

In faster sinus tachycardias, the P wave can sometimes be buried in the T wave of the preceding beat.

Question 22

The P wave appears different only when the pacemaker site originates from a site other than the SA node.

Question 23

The P' wave looks the same no matter where it originates or the direction the electrical impulse travels through the atria.

Question 24

The P- wave is absent with a blocked early beat that arises from the atria.

Question 25

P waves that originate in the SA node but conduct abnormally through altered, damaged atria should look normal.

Question 26

The P wave is the first deflection from the baseline at the beginning of the cardiac cycle.

Question 27

Notched or wide (enlarged) P waves may be seen with increased left atrial pressure and right atrial enlargement.

Question 28

Biphasic P waves are normal in lead V1.

Question 29

The atrial-to-ventricular conduction ratio of impulses is always 1 to 1.

Question 30

The waveforms seen when the atria fire in excess of 350 BPM are referred to as f waves.