Cardiovascular Drugs: Antidysrhythmics

Question 1

What is happening during the P wave

Answer 1

atrial depolarization

Question 2

What is happening during the PR interval

Answer 2

impulse pauses at AV node

Question 3

What is happening during the QRS complex?

Answer 3

ventricles depolarize

Question 4

What is happening during ST interval?

Answer 4

ventricles pause before repolarization

Question 5

What is happening during T wave?

Answer 5

ventricles repolarize

Question 6

Where in the EKG do the atria repolarize?

Answer 6

Hidden within the QRS complex

Question 7

What ions are involved with electrophysiology of myocyte?

Answer 7

Na+, K+, Cl-, Ca++

Question 8

Which ion rushes into the myocyte to elicit contraction?

Answer 8

Na+

Question 9

Which ion leaves the myocyte to allow for repolarization?

Answer 9

K+

Question 10

Which ion prolongs repolarization in the myocyte?

Answer 10

Ca++

Question 11

Which ion initiates depolarization of the SA node?

Answer 11

Na+ (funny current)

Question 12

Which ion rushes in and elicits depolarization of SA node?

Answer 12

Ca++

Question 13

Efflux of which ion results in SA node repolarization?

Answer 13

K+

Question 14

List supraventricular arrhythmias

Answer 14

atrial fibrillation
atrial flutter
atrial tachycardia (like SVT)

Question 15

List ventricular arrhythmias

Answer 15

ventricular fibrillation (vfib)
ventricular tachycardia (vtach)
PVCs
torsades

Question 16

Two bradycardic arrhythmias

Answer 16

heart block
sick sinus syndrome

Question 17

What ion do Class I antidysrhythmics inhibit?

Answer 17

Na+

Question 18

What do class II antidysrhythmics inhibit?

Answer 18

B1 receptors

Question 19

What ion do class III antidysrhythmics inhibit?

Answer 19

K+

Question 20

What ion do class IV antidysrhythmics inhibit?

Answer 20

Ca++

Question 21

List some class I antidysrhythmics

Answer 21

quinidine
procainamide
lidocaine
flecainide
propafenone

Question 22

How do the class subtypes of class I antidysrhythmics differ?

Answer 22

IA = increase AP, ERP, QT interval
IB = decrease AP, ERP
IC = increase ERP in AV node only

Question 23

which subtype of beta blockers are used as class II antidysrhythmics?

Answer 23

cardioselective usually

Question 24

results of beta 1 antagonism

Answer 24

decreased HR
decreased contractility
decreased conduction through AV node

Question 25

adverse effects of beta antagonism

Answer 25

bradycardia hypotension

Question 26

name a class III antidysrhythmic

Answer 26

amiodarone

Question 27

What is amiodarone used for

Answer 27

ventricular dysrhythmias

Question 28

how long is amiodarone's half life?

Answer 28

25-60 days

Question 29

adverse effects of amiodarone

Answer 29

pulmonary fibrosis hypothyroidism hepatotoxicity *pro-dysrhythmic: torsades, bradycardia, AV block

Question 30

What is a dihydropyridine

Answer 30

ca++ channel blocker that only impacts the vasculature (results in arteriole vasodilation)

Question 31

What is a nondihydropyridine

Answer 31

ca++ channel blocker that works on the arteries (arterial vasodilation) AND on the heart (decreased contractility, HR, AV node conduction)

Question 32

Which type of Ca++ blocker is used in treatment of dysrhythmias

Answer 32

nondihydropyridines

Question 33

List some dihydropyridines

Answer 33

amlodipine nifedipine nicardipine

Question 34

list some nondihydropyridines

Answer 34

diltiazem verapamil

Question 35

Which two classes of antidysrhythmics are contraindicated together?

Answer 35

Class II & Class IV (beta blockers and Ca++ channel blockers)

Question 36

What does adenosine do?

Answer 36

hyperpolarize cardiac membranes = no AP can occur (kinda stops the heart for a sec!)

Question 37

half life of adenosine

Answer 37

10 seconds

Question 38

How to administer adenosine

Answer 38

rapid IV push followed immediately by rapid saline flush

Question 39

adverse effects of adenosine

Answer 39

flushing transient hypotension transient flat line transient chest pain

Question 40

mechanism of action of digoxin

Answer 40

Na+/K+ ATPase inhibition = increased Na+ and therefore increased Ca++ = increased contractility

Question 41

drug class of digoxin

Answer 41

cardiac glycoside

Question 42

does digoxin cause tachycardia or bradycardia?

Answer 42

bradycardia potentially

Question 43

adverse effect of digoxin

Answer 43

arrhythmias AV block toxicity

Question 44

contraindications of digoxin

Answer 44

heart block hypokalemia (can lead to drug toxicity) WPW advanced CKD

Question 45

What class of medication is atropine

Answer 45

anticholinergic (or muscarinic antagonist)

Question 46

Cardiac effects of atropine

Answer 46

increased HR

Question 47

uses for atropine as an antidysrhythmic

Answer 47

symptomatic bradycardia (1mg Q3-5mins)

Question 48

adverse effects of atropine

Answer 48

decreased GI/GU dry mouth mydriasis