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Flashcards in Arrhythmia meds Deck (71):
1

Major problems w/ A-Fib

Atrial thrombi
Right atrium: PE
Left atrium: cerebral emboli (stroke)

2

How much greater risk are a-fib pts of stroke than pts w/o afib

2xs

3

What percent of people who could use prophylactic anticoagulation therapy recieve treatment?

15-44%

4

AF treatment strategy

See slide 17

5

How do you treat a pt who is not compromised and >48 hours (or dont know how long) pt is in a-fib?

With rate control anticoagulation
*conversion to an sinus rhythm might dislodge a thrombus*

6

Oral anticoagulation-warfarin therapeutic INR

See slide 21 for graph

7

What is the safest antiarrythmic?

Amiodarone

8

What is the IV loading dose of amiodarone?

150 mg over 10 minutes

9

Can you give amiodarone if you have an iodine allergy?

Yes

10

Side effects of amidarone

Hypothyroid
Hyperthyroid
Pulmonary fibrosis
Lenticular opacities
Blue skin discolorations

11

What is the rate of conversion rate w/ amiodarone?

60%

12

What do we use Dronedarone (amiodarone "lite") for?

For a-fib/flutter who have converted

13

Is dronedarone affected by iodine?

Yes; no iodine to limit toxicity

14

What is the black box warning for dronedarone?

Dronedarone is contraindicated in NYHA class IV HF or NYHA class II-III HF w/ recent decomepnsation
(increased HF deaths in clinical trials)

15

What is the MOA of sotalol?

Blocks beta 1 and beta 2 receptors

16

What is sotalol used for?

Used to maintain sinus rhythm after conversion

17

How is sotalol eliminated? Does it need an adjustment?

Renally
Yes, dose needs to be adjusted for impairment

18

When is sotalol contraindicated for A-Fib?

If CrCl < 40 mL/min

19

What is the dose adjustment for ventricular arrhythmia with a CrCL<10?

Individualize it based on pt presentation

20

What is propafenone indicated for?

Atrial fibrillation/flutter

21

What is Diltiazem?

A rate controlling calcium channel blocker (CCB)

22

How is diltiazem dosed?

IV and PO

23

What form of diltiazem do you use when giving PO?

CD form

24

What beta blockers can you use for rate control?

Metoprolol
Carvedilol

25

What populations does Digoxin work better with?

Pts w/ EF <40%
Pts w/ low BP
Pts w/ positive inotrope

26

What does a positive inotrope indicate

Increases force myocardial contraction

27

How is digoxin dosed?

Micrograms

28

Is the half-life of digoxin long or short? Give time

Long
36-48 hours

29

How do you dose IV digoxin for atrial fibrillation

500 mcg IVP x1; then 250 mcg q 6 hours x2 doses

30

How do you dose oral digoxin for a-fib?

0.5 mg once daily x2 days

31

What is the dosing of digoxin for supraventricular tachycardia?

Total dizitizing dose (TDD) = 10-15 mcg/kg

32

What is included in the CHADS2 index and how many points do you get for each thing?

1 point for each:
CHF, recent
HTN
Age >= 75
DM
Stroke (hx or TIA)

33

Stroke risk w/ non-valvular AF-CHADS2 index

see slide 44

34

Conclusions from study

none of the postulated benefits of a rhythm – control strategy were confirmed. The rate – control strategy eliminated the need for rerpeated cardioversion and reduced rates of hospitalization

Rate control should be considered a primary approach for patients with atrial fibrillation and congestive heart failure

35

Do you want to pursue or avoid anti-arrhythmic drugs?

Avoid

36

Is there a mortality benefit for rhythm control?

No

37

Is rate control the primary approach?

Yes

38

Can you abandon rhythm control?

Yes, early, if not satisfactory

39

Is pharmacological conversion as efficacious as electrical?

No, but it is simpler

40

Is there a risk of toxicity of antiarrhythmic drugs?

Yes, there is a major risk

41

When is pharmacologic conversion most effective?

If performed <= 7 days of onset of AF

42

When is pharmacological conversion less effective?

If AF started > 7 days ago

43

What risk do electrical and pharmacological conversion methods carry if AF > 48 hours?

Thromboembolism

44

What is the difference in thromboembolism risk between pharmacological and electrical conversion methods?

Not much, similar risk

45

What drugs are commonly used for AF conversion?

Amiodarone (IV/po)
Ibutilide (IV)
Dofetilide (PO)

46

What is the most preventable cardiac arrhythmia?

Atrial fibrillation

47

How much more at risk are pts w/ afib of having a stroke

>5xs increased stroke risk

48

What anticoagulant has shown to reduce ischemic stroke risk?

Warfarin

49

What RFs are associated with intracranial hemorrhage?

Age, INR

50

What is ventricular tachycardia often precipitated by?

Electrolyte disturbances
Hypoxemia
Digitalis toxicity
Acute MI or ischemia (MC)

51

What is the drug of choice for ventricular arrhythmias (VA)?

Amiodarone!

52

What IV load of amiodarone do you give for VA

300 mg IV load

53

What are the risks of drugs used for v-tach?

All cause ventricular arrhythmias
All are potentially dangerous

54

What is adenosine?

An anti-arrhythmic and a diagnostic agent

55

How long is the half life of adenosine?

Short -> seconds

56

What is the MOA of adenosine?

Slows conduction through AV node -> Interrupts re-entrant pathways -> restores sinus rhythm

57

What is a negative SE of adenosine?

Prolonged sinus pauses

58

What is a rare risk of adenosine

Prolonged asystole

59

Does adenosine convert AF/flutter to sinus rhythm?

No

60

When is adenosine used diagnostically?

When the underlying rhythm is not apparent

61

How is adenosine delivered?

Over 1-2 seconds via a peripheral line

62

What do you follow each adenosine bolus with?

20 mL normal saline

63

Where do you want to administer adenosine?

As close to the trunk as possible

64

Where can you not deliver adenosine through?

Hand
Lower arm
Lower extremity

65

When is adenosine contraindicated

2nd or 3rd degree heart block
Sick sinus syndrome
Symptomatic bradycardia (except w/ functioning PM)
AF/flutter w/ underlying WPW syndrome
Asthma

66

Why do you want to avoid anti-arrhythmic drugs?

Most are pro-arrhythmic, especially when used long term

67

How do you classify antiarrhythmic drugs?

By the Vaughan Williams classification

68

What is the MOA of class 1 VW antiarrhythmics?

Sodium channel blockage

69

What is the MOA of class 2 VW antiarrhythmic drugs?

Beta adrenoceptor antagonists

70

What is the MOA of class 3 VW antiarrhythmic drugs?

Prolong action potential and refractory period

71

What is the MOA of class 4 VW antiarrhythmic drugs?

Calcium channel antagonists