CV & Renal: Antiarrhythmics

Question 1

What is a serious risk of all anti-arrhythmic drugs?

Answer 1

can precipitate lethal arrhythmia

Question 2

Which three populations should be especially worried for arrhythmia development?

Answer 2

80% of MI

50% anesthetized patients

25% digoxin patients

Question 3

What four factors can lead to decreased conduction?

Answer 3

Increased Threshold Potential: > -40

Decreased Maximum Diastolic Potential (Hyperpolarization): < -65

Decreased Slope of Phase 4 (Slower funny current)

Increased AP duration

Question 4

What is the major mechanism for arrhythmia?

Answer 4

unidirectional block and reentry

Question 5

What are the two main goals for arrhythmia therapy?

Answer 5

↓ Pacemaker Activity

Modify conduction/AP to disable reentry

Question 6

What are Class IA arrhythmics, and what type of channels do they work on?

Answer 6

Quinidine, procainamide

open, active sodium channels

Question 7

Quinidine and procainamide can block what two channel types?

Answer 7

open, active sodium channels (decrease phase 0 slope)

potassium channels (prolong AP, ERP)

Question 8

Blockage of potassium channels by quinidine or procainamide has what effect?

Answer 8

prolonged ADP and ERP

Question 9

Blocking open and active sodium channels by quinidine and procainamide has what effect?

Answer 9

“State dependent” blockade

Normal cells: slowing max rise of action potential

Damaged cells: no depolarization

Question 10

What are three major adverse effects of quinidine?

Answer 10

Torsades

Widened QRS/QT and quinidine syncope/death

Chinconism

Question 11

Slow acetylators can have what adverse effect with procainamide?

Answer 11

SLE

Question 12

Which Class IA drug is a HIP drug?

Answer 12

procainamide

Question 13

This drug blocks inactivated sodium channels, therefore blocking window current leading to shortened APD (increased phase 0 slope)

Answer 13

Lidocaine

Question 14

Lidocaine has preference for (healthy/damaged) tissue

Answer 14

damaged

Question 15

lidocaine is only effective where?

Answer 15

purkinje/ventricles

Question 16

What is the DOC for acute ventricular arrythmia?

Answer 16

lidocaine

Question 17

What is quinidine and procainamide used for?

Answer 17

acute/chronic tx of SV and ventricular arrhythmia

Question 18

Which drug is a class IC antiarrhythmic?

Answer 18

flecainide (tambocor)

Question 19

This drug has strong blockage of all sodium channel states and is slow to dissociate from binding. (big decrease in phase 0 slope)

It has no effect on ERP

Answer 19

Flecainide (tambocor)

Question 20

This drug is used in the following situations:

SV Arrhythmias

Life threatening ventricular arrhythmia

Drug of last resort

Answer 20

flecainide (tambocor)

Question 21

This drug is strongly pro-arrhythmic

Answer 21

flecainide (tambocor)

Question 22

What three drugs are class II antiarrhythmics?

Answer 22

propranolol, metoprolol, esmolol

Question 23

Which class II beta blocker has the following characteristics?

Short t1/2
IV admin
2nd line for acute PSVTs

Answer 23

esmolol

Question 24

What two drugs are Class III antiarrhythmics?

Answer 24

amiodarone, sotalol

Question 25

This class III antiarrhythmic is the "jack of all antiarrhythmics"

Answer 25

amiodarone

Question 26

This drug has the following mechanisms: Primary: block K+ Channels (Class III effect) ``` Others: Block Na+ Channels (Class I) Beta Blocker (Class II) Some Ca2+ channel blocking (Class IV) Alpha Blocker ```

Answer 26

Amiodarone

Question 27

Which drug is DOC for Ventricular Arrhythmia (used in ACLS protocols)

Answer 27

amiodarone

Question 28

A patient presents with yellowish cornea, bluish gray skin. what drug likely caused this?

Answer 28

amiodarone

Question 29

Why does amiodarone cause thyroid dysfunction?

Answer 29

it contains iodine

Question 30

What drug hast he following adverse effects? ↓ Sinus Rate, ↓ Conduction ↑ QT w/out Torsades Pulmonary Fibrosis Photodermatitis

Answer 30

amiodaraone

Question 31

describe the half-life and route of admin for amiodarone?

Answer 31

PO admin half life: 13-103 days

Question 32

Amiodarone and sotalol are/aren't able to treat both ventricular and SV arrhythmias

Answer 32

are

Question 33

This Class III drug has the following mechanism... K+ Block → APD Non-specific Beta Blocker

Answer 33

sotalol

Question 34

Does amiodarone cause torsades?

Answer 34

no

Question 35

Which Class III drug causes torsades?

Answer 35

sotalol

Question 36

These drugs only works in the atria, and therefore is useful in the below arrhythmias: Reentrant SVT PSVT A. Fib/flutter

Answer 36

Verapamil, Diltiazem (Class IV)

Question 37

What are two adverse effects of Class IV drugs (verapamil, diltiazem)

Answer 37

negative inotropic can't be used with beta blockers

Question 38

Which drug has the following mechanism? ↑ K+ Conductance & ↓ cAMP-induced Ca2+ influx → hyperpolarization → heart reset

Answer 38

Adenosine

Question 39

this is the DOC for acute PSVT and WPW syndrome. It is only useful for reentry arrhythmias

Answer 39

Adenosine

Question 40

What are the 5 adverse effects of Adenosine?

Answer 40

``` Flushing SOB CP Hypotension HA ```

Question 41

this is the DOC for torsades

Answer 41

Magnesium

Question 42

Magnesium has what 4 indications?

Answer 42

DOC for Torsade Antiarrhythmic effects in patients w/ normal Mg levels Digitalis induced arrhythmia Seizer mgmt

Question 43

What is the route of admin for magnesium?

Answer 43

IV

Question 44

This drug causes increased potassium permeability and therefore hyperpolarization

Answer 44

Potassium

Question 45

Potassium administration decreases what four things?

Answer 45

↓ APD, Conduction, Pacemaker Rate, Pacemaker Arrythmogenesis

Question 46

Preferred treatment order for acute PSVT...

Answer 46

Adenosine > Esmolol > IV CCBs

Question 47

Preferred treatment order for Chronic PSVT?

Answer 47

Beta Blockers > CCBs

Question 48

Which two drug classes can't treat both SV and ventricular arrhythmia?

Answer 48

Class IV (SV only) Class IB (ventricular only)

Question 49

Which antiarrhythmic prolongs QT without torsades?

Answer 49

amiodarone

Question 50

Arrhythmic prophylaxis can be achieved with what two drugs?

Answer 50

beta blockers CCBs