Section 3: Pharmacology

Question 1

Vaughn Williams Classification

Answer 1

SoBePoCa

Question 2

Class I

Answer 2

Sodium Channel Blockers

Question 3

Do Class I increase or decrease the speed of depolarization?

Answer 3

Decrease speed of depolarization

Question 4

Class I Action Potential Trend

Answer 4

1a- shift
1b- shorter
1c- tilt

Question 5

Class Ia

Answer 5

moderate Na channel blocking, prolongs refractory, dec conduction velocity

Question 6

class 1b

Answer 6

weak Na channel blocking, dec action potential, shorten refractory

Question 7

class 1c

Answer 7

strong na channel blocker, dec conduction velocity, little effect on refractory

Question 8

class II

Answer 8

beta blocking

Question 9

what effect do class II have on sympathetic tone

Answer 9

dec sympathetic tone

Question 10

class III

Answer 10

potassium channel blocking

Question 11

what do class III drugs do

Answer 11

inc action potential duration

Question 12

class IV drugs

Answer 12

calcium channel blockers

Question 13

what do calcium channel blockers do/affect

Answer 13

affect SA and AV nodes, slow automaticity, and conduction time

Question 14

what do class V drugs do

Answer 14

increase parasympathetic effects via unknown/various methods

Question 15

Class Ia Drug Examples

Answer 15

Double Quarter Pounder

- Disopyramide, Quinidine, and Procainamide

Question 16

Background on 1a drugs

Answer 16

1A (a)- does it All
effective in A and V
moderately effective for most tachyarrythmias
severe side effects
can cause torsades- monitor QRS width and QT prolongation
procainamide - affects pathways
can enhance av conduction

Question 17

Class 1b drug examples

Answer 17

Lettuce, Pickle, Tomato, Mustard

-lidocaine, phenytoin, tocainide, mexiletine

Question 18

background on 1b drugs

Answer 18

less likely than 1a to be proarrythmic
used and ok at treating v
CNS side effects
lidocaine used for short term IV therapy

Question 19

class 1 c drug examples

Answer 19

Enjoy More Fries Please

- Encainide (bad), muncizine, flecainide, propafenone

Question 20

background on 1c drugs

Answer 20

similar effects on a and v
not commonly used
proarrythmic for SHD and ischemic patients
can be used for A and life threatening V
not for patients with structural heart disease

Question 21

Class II drug examples

Answer 21

(the -olols)

- atenolol, cavedilol, metopropolol, labetalol, nadolol, timolol

Question 22

class II drugs background

Answer 22

dec automaticity in sa node causing slower hr
less effective at suppressing arrythmia
NOT good for COPD or asthma

Question 23

class III drug examples

Answer 23

(A Big Dog Is Scary)

Amiodarone, Bretylium, Dofetilide, Ibutilide, Sotalol

Question 24

Sotalol

Answer 24

decrease DFT, inc pacing threshold

• defib threshold, how much energy it takes to shock out of VT/VF

Question 25

Amiodarone

Answer 25

Inc DFT, 45 day half life requires long loading period, requires frequent tests

Question 26

Ibutilide

Answer 26

Used acutely for cardioversion (IV)

Question 27

DFT

Answer 27

Defib threshold, how much energy it takes to shock out of VF/VT

Question 28

sotalol and tikosyn

Answer 28

excreted by the kidney, AF and AFL, 3 day hospital admission at initiation

Question 29

Class IV Examples

Answer 29

Diltiazem, Verapamil

Question 30

Class IV drugs function

Answer 30

depress automaticity, slow conduction, dec refractoriness, used for SVT, various degrees of heart block can occur

Question 31

Class V examples

Answer 31

digoxin, digitoxin, adenosine

Question 32

class V uses

Answer 32

affects SA and AV nodes, inc vagal tone, parasympathetic action

Question 33

digoxin

Answer 33

inc contractile force and used for HF therapy

Question 34

adenosine

Answer 34

terminate SVT, very short half life (30 s)

Question 35

Least Invasive Drugs for pregnancy

Answer 35

acute SVT- vagal maneuver, adenosine, DCCV, metoprolol, propranolol, verapamil
prophylaxis- digoxin, metoprolol after 1st trimester

Question 36

ACLS (advanced cardiac life support)- what is the first line with any rhythm?

Answer 36

oxygen