Arrhythmia meds

Question 1

Major problems w/ A-Fib

Answer 1

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

Question 2

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

Answer 2

2xs

Question 3

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

Answer 3

15-44%

Question 4

AF treatment strategy

Answer 4

See slide 17

Question 5

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

Answer 5

With rate control anticoagulation

conversion to an sinus rhythm might dislodge a thrombus

Question 6

Oral anticoagulation-warfarin therapeutic INR

Answer 6

See slide 21 for graph

Question 7

What is the safest antiarrythmic?

Answer 7

Amiodarone

Question 8

What is the IV loading dose of amiodarone?

Answer 8

150 mg over 10 minutes

Question 9

Can you give amiodarone if you have an iodine allergy?

Answer 9

Yes

Question 10

Side effects of amidarone

Answer 10

Hypothyroid
Hyperthyroid
Pulmonary fibrosis
Lenticular opacities
Blue skin discolorations

Question 11

What is the rate of conversion rate w/ amiodarone?

Answer 11

60%

Question 12

What do we use Dronedarone (amiodarone “lite”) for?

Answer 12

For a-fib/flutter who have converted

Question 13

Is dronedarone affected by iodine?

Answer 13

Yes; no iodine to limit toxicity

Question 14

What is the black box warning for dronedarone?

Answer 14

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

Question 15

What is the MOA of sotalol?

Answer 15

Blocks beta 1 and beta 2 receptors

Question 16

What is sotalol used for?

Answer 16

Used to maintain sinus rhythm after conversion

Question 17

How is sotalol eliminated? Does it need an adjustment?

Answer 17

Renally

Yes, dose needs to be adjusted for impairment

Question 18

When is sotalol contraindicated for A-Fib?

Answer 18

If CrCl < 40 mL/min

Question 19

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

Answer 19

Individualize it based on pt presentation

Question 20

What is propafenone indicated for?

Answer 20

Atrial fibrillation/flutter

Question 21

What is Diltiazem?

Answer 21

A rate controlling calcium channel blocker (CCB)

Question 22

How is diltiazem dosed?

Answer 22

IV and PO

Question 23

What form of diltiazem do you use when giving PO?

Answer 23

CD form

Question 24

What beta blockers can you use for rate control?

Answer 24

Metoprolol

Carvedilol

Question 25

What populations does Digoxin work better with?

Answer 25

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

Question 26

What does a positive inotrope indicate

Answer 26

Increases force myocardial contraction

Question 27

How is digoxin dosed?

Answer 27

Micrograms

Question 28

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

Answer 28

Long | 36-48 hours

Question 29

How do you dose IV digoxin for atrial fibrillation

Answer 29

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

Question 30

How do you dose oral digoxin for a-fib?

Answer 30

0.5 mg once daily x2 days

Question 31

What is the dosing of digoxin for supraventricular tachycardia?

Answer 31

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

Question 32

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

Answer 32

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

Question 33

Stroke risk w/ non-valvular AF-CHADS2 index

Answer 33

see slide 44

Question 34

Conclusions from study

Answer 34

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

Question 35

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

Answer 35

Avoid

Question 36

Is there a mortality benefit for rhythm control?

Answer 36

No

Question 37

Is rate control the primary approach?

Answer 37

Yes

Question 38

Can you abandon rhythm control?

Answer 38

Yes, early, if not satisfactory

Question 39

Is pharmacological conversion as efficacious as electrical?

Answer 39

No, but it is simpler

Question 40

Is there a risk of toxicity of antiarrhythmic drugs?

Answer 40

Yes, there is a major risk

Question 41

When is pharmacologic conversion most effective?

Answer 41

If performed <= 7 days of onset of AF

Question 42

When is pharmacological conversion less effective?

Answer 42

If AF started > 7 days ago

Question 43

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

Answer 43

Thromboembolism

Question 44

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

Answer 44

Not much, similar risk

Question 45

What drugs are commonly used for AF conversion?

Answer 45

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

Question 46

What is the most preventable cardiac arrhythmia?

Answer 46

Atrial fibrillation

Question 47

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

Answer 47

>5xs increased stroke risk

Question 48

What anticoagulant has shown to reduce ischemic stroke risk?

Answer 48

Warfarin

Question 49

What RFs are associated with intracranial hemorrhage?

Answer 49

Age, INR

Question 50

What is ventricular tachycardia often precipitated by?

Answer 50

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

Question 51

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

Answer 51

Amiodarone!

Question 52

What IV load of amiodarone do you give for VA

Answer 52

300 mg IV load

Question 53

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

Answer 53

All cause ventricular arrhythmias | All are potentially dangerous

Question 54

What is adenosine?

Answer 54

An anti-arrhythmic and a diagnostic agent

Question 55

How long is the half life of adenosine?

Answer 55

Short -> seconds

Question 56

What is the MOA of adenosine?

Answer 56

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

Question 57

What is a negative SE of adenosine?

Answer 57

Prolonged sinus pauses

Question 58

What is a rare risk of adenosine

Answer 58

Prolonged asystole

Question 59

Does adenosine convert AF/flutter to sinus rhythm?

Answer 59

No

Question 60

When is adenosine used diagnostically?

Answer 60

When the underlying rhythm is not apparent

Question 61

How is adenosine delivered?

Answer 61

Over 1-2 seconds via a peripheral line

Question 62

What do you follow each adenosine bolus with?

Answer 62

20 mL normal saline

Question 63

Where do you want to administer adenosine?

Answer 63

As close to the trunk as possible

Question 64

Where can you not deliver adenosine through?

Answer 64

Hand Lower arm Lower extremity

Question 65

When is adenosine contraindicated

Answer 65

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

Question 66

Why do you want to avoid anti-arrhythmic drugs?

Answer 66

Most are pro-arrhythmic, especially when used long term

Question 67

How do you classify antiarrhythmic drugs?

Answer 67

By the Vaughan Williams classification

Question 68

What is the MOA of class 1 VW antiarrhythmics?

Answer 68

Sodium channel blockage

Question 69

What is the MOA of class 2 VW antiarrhythmic drugs?

Answer 69

Beta adrenoceptor antagonists

Question 70

What is the MOA of class 3 VW antiarrhythmic drugs?

Answer 70

Prolong action potential and refractory period

Question 71

What is the MOA of class 4 VW antiarrhythmic drugs?

Answer 71

Calcium channel antagonists