Arrythmias Flashcards Preview

AU 15 - Pharmacology Exam 3 > Arrythmias > Flashcards

Flashcards in Arrythmias Deck (52):
1

Rhythm

Movement or procedure with uniform or patterned recurrence of a beat, accent, or the like

2

Cardiac Arrhythmia

Heartbeat is irregular, too fast, or too slow

3

What does the P wave represent?

Atrial depolarizaiton

4

What does the QRS complex represent?

Ventricular depolarization

5

What does the T wave represent?

Ventricular repolarization

6

Contraction of the atria does what?

Moves blood into the ventricles

7

Contraction of the right ventricle does what?

Sends O2 depleted blood to the lungs

8

Contraction of the left ventricle does what?

Sends O2 rich blood to the body

9

What coordinates cardiac muscle contraction?

Electrical signals

10

Trace the circulation of blood through the heart

Vena cava --> R atrium --> R ventricle --> Pulmonary artery --> Lungs --> L atrium --> L ventricle --> Aorta --> rest of the body

11

Trace the electrical current through through the conducting system through the heart

SA node --> AV node (signal pauses) --> AV bundle branches --> Purkinje fibers

12

Where is the signaling velocity slowest in the heart?

AV node

13

Where is the signaling velocity fastest in the heart?

Purkinje fibers

14

What creates the EKG?

The sum total of action potentials traveling through the heart

15

What does the PR interval describe?

The time it takes for the impulse to travel from the Sinus node through the AV node

16

What does the ST segment represent?

The time the ventricles are depolarized

17

What does the U wave represent?

Repolarization of the intraventricular septum

18

What is the QT interval?

The speed of the heart beat

19

What are the four main types of arrhythmias?

Extra beats
Supreaventricular tachycardias
Ventricular arrhythmias
Bardyarrhythmias

20

Extra beat arrhythmia types

Premature atrial contraction
Premature ventricular contractions

21

Supraventricular tachycardia types

Atrial fibrilation
Atrial flutter
Paroxysmal supraventricular tachycardia

22

Ventricular arrhythmia types

Ventricular fibrilation
Ventricular tachycardia

23

Bradyarrhythmias

Slow heartbeat

24

What are the classifications of arrhythmias by site of origin?

Atrial
Ventricular
Juncitonal
AV Heart Blocks

25

Atrioventricular Blocks

Conduction between the atria and ventricles is blocked or slowed
Can be primary, secondary, tertiary

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Primary AV Block

PR interval is lengthened beyond 0.2 seconds

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Secondary AV block

Disturbance, delay, or interruption of atrial impulse conduction through the AV node to the ventricles

28

Tertiary AV block

aka Complete heart block
Impulse generated in SA node does not propagate to the ventricles

29

How will a primary AV block look on an EKG

PR interval is lengthened

30

How will a secondary AV block look on an EKG

There will be QRS complexes dropped

31

How will a tertiary AV block look on an EKG?

None of the p waves conduct to ventricles - P-P and QRS-QRS are independent

32

What are the causes of arrhythmias?

Cardiac ischemia
Excessive discharge or sensitivity to autonomic neurotransmitters
Exposure to toxic substances (smoking, alcohol, Rx meds, caffeine, nicotine)
Unknown etiology

33

What occurs in phase 0 of cardiac action potential

Na goes into the cell (depolarization)

34

What occurs in phase 1 of cardiac action potential?

K and Cl leave the cell

35

What occurs in phase 2 of cardiac action potential?

Ca goes into the cell
K goes out of the cell
Plateau phase

36

What occurs in phase 3 of the cardiac action potential?

K goes out of the cell
Repolarization

37

What are the classes of Anti-Arrhythmic Drugs?

Class I
Class II
Class III
Class IV

38

Class I Anti-arrhythmic drugs

Block Na channels

39

What are the different classes of Class I anti-arrhythmic drugs and when are they used?

Ia
Ib
Ic

40

Class II Anti-arrhythmic drugs

B-adrenoceptor antagonists
Diminish phase 4 depolarization - depressing automaticity, prolonging AV conduction, decreasing HR and contractility
Can diminish both Na and Ca currents

41

Class III Anti-arrhythmic drugs

K channel blockers
Delay the ventricular AP (specifically repolarization)
Prolong refractory period

42

Class IV Anti-arrhythmic drugs

Ca channel antagonists
Decrease Ca inward current, decreasing phase 4 spontaneous depolarization
Slow conduction and increase the refractory period

43

Ia Na channel blockers

Lengthen the duration of the AP
Bind more selectively to the open state of the channel
Dissociates from the channel with intermediate kinetics (1-10 seconds)

44

Ib Na channel blockers

Shorten the duration of the AP
Bind primarily to inactivated state of the channel
Dissociates from the channel with rapid kinetics (

45

Ic Na channel blockers

Minimal effect on the duration of the action potential
Bind more selectively to the open state of the channel
Dissociate from the channel with slow kinetics (>10 seconds)

46

What are Class II Anti-arrhythmias used to treat?

Useful in treating tachyarrhythmias caused by increased sympathetic activity
Also used for atrial flutter and fibrillation

47

T/F - Class II and Class III compound, but Class I and Class III do not

True

48

What are Class III Anti-arrhythmias used to treat?

Ventricular arrhythmias - especially ventricular fibrillation or tachycardia

49

What phase of the Ventricular AP do Class I Anti-arrhythmic drugs effect?

Phase 0

50

What phase of the Ventricular AP do Class II Anti-arrhythmic drugs effect?

Phase 4

51

What phase of the Ventricular AP do Class III Anti-arrhythmic drugs effect?

Phase 3

52

What phase of the Ventricular AP do Class IV Anti-arrhythmic drugs effect?

Phase 2