Chapter 6

Question 1

What are atrial dysrhythmias caused by?

Answer 1

Ectopic impulses in either atria which affects the SA node and increases the heart rate

Question 2

Ectopic impulses

Answer 2

Referes to an electrical impulse that comes from outside of the normal pacemaker site or electrical conduction pathway.

Question 3

What dysrhythmias are caused by ectopic impulses?

Answer 3

Premature atrial complexes, atrial tachycardia, atrial flutter, and atrial fibrillation

Question 4

Atrial dysrhythmias occur from conditions such as

Answer 4

Damage to the atria from MI, valvular problems, ot neurological influences

Question 5

Which wave form is affected by the change in electrical activity within the atria?

Answer 5

P waves

Question 6

What are premature atrial complexes (PAC)

Answer 6

Electrical impulses that originate in the atria and initiate an early impulse that interrupts the inherent regular rhythm. The atria do not achieve the maximum lood capacity prior to contraction, lack of blood causes low cardiac output and less volume in the ventricles prior to ventricular contraction.

Question 7

PAC criteria for classification

Answer 7

A PAC is a cardiac complex that occurs too soon. It has a positively deflected P wave. Other than being “early”, this complex does not possess nay abnormal features

Question 8

Biphasic

Answer 8

The waveform that has two phases; an equally positive (upward) and negative (downward) deflection on the ECG tracing

Question 9

Trigeminy

Answer 9

Refers to a pattern in wich every third complex is a premature beat

Question 10

How to determine a PAC

Answer 10

Determine the underlying rhythm of NSR, S.Brady, S.Tachy or S.Dys followed by a description of the PAC (ex: sinus rhythm with trigeminal PACs

Question 11

Signs and sx’s

Answer 11

Those of low cardiac output, palpitations , depend on frequency of PACs

Question 12

Wandering Atrial Pacemaker (WAP)

Answer 12

Rhythm in which the pacemaker site shifts between the SA node, atria, and/or the AV junction. P wave configuration changes in the same lead

Question 13

When is WAP a normal finding?

Answer 13

WAP is a normal finding in children, older adults, and well-conditioned athletes

Question 14

Signs and sx’s of WAP

Answer 14

None. May be related to some types of organic heart disease and drug toxicity

Question 15

WAP criteria and classification

Answer 15

Has a changing P wave configuration with at least three variations in one lead. The rhythm may be irregular

Question 16

Multifocal Atrial Tachycardia (MAT)

Answer 16

Has a P wave that changes from beat to beat and a heart rate of 101 to 150. It has the same characteristics as wandering atrial pacemaker (WAP), with the only difference being that the rate is in excess of 100.

Question 17

MAT criteria and classification

Answer 17

MAT has a clearly changing P wave and a heart rate of 101 to 150 beats per minute

Question 18

Atrial flutter

Answer 18

Occurs when rapid impulse originates in the atrial tissue. Has several F waves. Will lead to more serious dysrhythmias if not treated.

Question 19

Ectopic focus origin in atrial flutter

Answer 19

From ischemic areas of the heart with enhanced automaticity of from a reentry pathway (sawtooth shape)

Question 20

What is a reentry pathway

Answer 20

An extra pathway that has developed where a group of cells will generate an impulse faster than the SA node (similar to finding a shortcut to school or work and bypassing traffic)

Question 21

How is atrial flutter described

Answer 21

The ratio of F waves to QRS complexes. Ex: atrial flutter 3:1

Question 22

Atrial flutter rate

Answer 22

Atrial rate will be between 250 and 350 bpm

Question 23

Atrial flutter criteria and classification

Answer 23

“sawtooth” atrial pattern between the QRS complexes, no identifiable P waves exist, PR interval cannot be measured. All other measures are noted as WNL

Question 24

What is loss of atrial flick

Answer 24

Occurs when blood is ejected into the ventricles by the atrial immediately prior to ventricular systole, sp atrial do not contract completely

Question 25

Signs and sx's of atrial flutter

Answer 25

None if the heart rate remains between 60-100, if it increases there will be sx's of low cardiac output

Question 26

Tx for atrial flutter

Answer 26

Oxygen therapy to ensure adequate supply to the vital organs and constant monitoring of rhythms so that it does not advance to atrial fibrillation

Question 27

Atrial fibrillation

Answer 27

Occurs when electrical impulses come from area of reentry pathways or multiple ectopic foci. Each electrical impulse depolorizes only a small area of the atria resulting in the failure fo the whole atria to contract as a whole, causing a quiver, blood is not pumped properly.

Question 28

What is the cardiac output in atrial fibrillation

Answer 28

Up to 30%

Question 29

What is the appearance of atrial fibrillation?

Answer 29

Fine scribbles, no P wave, chaotic

Question 30

Atrial rate in atrial fibrillation

Answer 30

375-700 bpm

Question 31

Atrial fibrillation criteria for classification

Answer 31

Shows chaotic atrial electrical activity with irregular R-R intervals. There is chaotic F waves

Question 32

Signs and sx's of atrial fibrillation

Answer 32

Those of decreased cardiac output. Loss of atrial kick. New onset Afib may present with dizziness, nausea, etc.

Question 33

Tx of atrial fibrillation

Answer 33

Use of medications first, then cardioversion if necessary to stabilize the pt's hr

Question 34

Possible conditions due to atrial fibrillation

Answer 34

Blood accumulated in the atria due to incomplete contraction of the atria which can allow the opportunity for a clot or thrombus to form. Increased risk of embolism. They may also be at risk to develop cerebral vascular accident (CVA), MI, PE, renal infarction or an embolism

Question 35

What are the similarities between atrial dysrhythmias

Answer 35

They are caused by an ectopic impulse in either of the atria

Question 36

PAC

Answer 36

Premature atrial complexes which are impulses that originate in the atria and initiate an early impulse that interrupts the inherent regular rhythm

Question 37

Identify wandering atrial pacemaker using the criteria for classification and explain how the rhythm may affect the pt, including basic pt care and tx

Answer 37

WAP is a rhythm in which the pacemaker site shifts between the SA node, atria, and/or the AV junction. The P wave configuration changes in appearance during the pacemaker shift

Question 38

Identify multifocal atrial tachycardia using the criteria for classification and explain how the rhythm may affect the pt, including basic pt care and tx

Answer 38

MAT has a P wave that changes form beat to beat and heart rate of 101 to 150 bpm

Question 39

Identify atrial flutter using the criteria for classification and explain how the rhythm may affect the pt, including basic pt care and tx

Answer 39

A flutter occurs when a rapid impulse originates in the atrial tissue. This dysrhythmia presents with a classic sawtooth or picket fence appearance known as flutter or F waves

Question 40

Identify atrial fibrillation using the criteria for classification and explain how the rhythm may affect the pt, including basic pt care and tx

Answer 40

A fib occurs when electrical impulses come from areas of reentry pathways or multiple ectopic foci. Each electrical impulse results in depolarization of only a small group of atrial cells rather than the whole attrai. This dysrhythmia presents with classic chaotic "f" waves between the irregular R-R intervals