ALS Lecture 13 - The Pharmacology of Rhythm Control DONE

Question 1

2 types of heart cells

Answer 1

pacemaker, myocyte

Question 2

Type 1 heart cells, pacemaker (4)

Answer 2

depolarise without stimulation, SA node, AV node, conduction tissue

Question 3

Type 2 heart cells, myocytes (3)

Answer 3

fire when stimulated, atria, ventricles

Question 4

muscle cells in diastole (phase 4) remain at

Answer 4

resting membrane potential of -90mv till stimulated

Question 5

3 properties of cardiac cells

Answer 5

automaticity, excitability, refractoriness

Question 6

automaticity

Answer 6

spontaneous depolarisation till threshold potential reached when cell fires (phase 0)

Question 7

spread of excitation sequence (8 steps)

Answer 7

1. SA node
2. atria
3. AV node
4. bundle of His
5. bundle branches
6. Purkinje fibres
7. endocardium to epicardium
8. apex to base

Question 8

label the diagram of the phases of excitation (A)

Answer 8

done

Question 9

phase 0 of cardiac action potential

Answer 9

rapid depolarisation, fast Na+ inflow

Question 10

phase 1 of cardiac action potential

Answer 10

initial rapid repolarisation due to Na+ closure, Cl- influx, outflow of K+

Question 11

phase 2 of cardiac action potential

Answer 11

plateau, delayed repolarisation by slow inward Ca+ and outflow of K+

Question 12

phase 3 of cardiac action potential

Answer 12

2nd period of repolarisation, continual K+ outflow and Ca2+ inflow

Question 13

what class is digoxin?

Answer 13

5

Question 14

what effect does digoxin do? (5)

Answer 14

slow HR, reduced AV conduction, increased contraction force, rhythm disturbance, increased ectopic pacemaker

Question 15

digoxin MOA (4 steps)

Answer 15

1. inhibits Na+K+ATPase pump
2. increased Na+, decreased K+
3. Na+/Ca2+ transported gets rid of Na+, bringing in Ca2+
4. strengthens ventricular contraction so more blood each beat

Question 16

Vaughan Williams classification, Class 1 agents interfere with

Answer 16

sodium channel

Question 17

Vaughan Williams classification, Class 1a agents

Answer 17

lengthen action potential

Question 18

Vaughan Williams classification, Class 1b agents

Answer 18

shorten action potential

Question 19

Vaughan Williams classification, Class 1c agents

Answer 19

no significant effect on action potential

Question 20

Vaughan Williams classification, Class 2 agents inhibit

Answer 20

sympathetic nervous system

Question 21

Vaughan Williams classification, Class 2 agents are mostly

Answer 21

beta-blockers

Question 22

Vaughan Williams classification, Class 3 agents inhibit

Answer 22

potassium channel

Question 23

Vaughan Williams classification, Class 4 agents inhibit (2)

Answer 23

calcium channels, AV node

Question 24

Vaughan Williams classification, Class 5 agents work by (2)

Answer 24

other, unknown

Question 25

fill in the table of different Vaughan Williams classification drugs (B)

Answer 25

done

Question 26

look at the diagrams of class 1a - 2 Vaughan Williams classification drugs (C)

Answer 26

done

Question 27

problems with Vaughan Williams classification drugs (2)

Answer 27

some have multiple effects, does not include important anti-arrhythmics

Question 28

fill in the table of Vaughan Williams classification class 5 drugs (D)

Answer 28

done

Question 29

label the diagram of drugs affecting cardiac action potential (E)

Answer 29

done

Question 30

3 disadvantages of using drugs in comparison with DC shock

Answer 30

may take days, side effects, useful adjunct

Question 31

3 disadvantages of using DC shock in comparison with drugs

Answer 31

doesn't always work, needs GA

Question 32

label the diagram of the heart and the nodes (F)

Answer 32

done

Question 33

lignocaine MOA (3)

Answer 33

1. sodium channel blocker 2. raises depolarisation threshold 3. heart less likely to initiate APs that may cause arrhythmia

Question 34

beta blockers examples (5)

Answer 34

bisoprolol, metoprolol, atenolol, carvedilol, nebivolol

Question 35

beta blockers are used in (5)

Answer 35

HTN, angina, post MI, arrhythmias, stable heart failure

Question 36

beta blockers MOA (4)

Answer 36

1. beta adrenergic receptor antagonists 2. inhibits sympathetic stimulation 3. reduces heart rate, contractility, blood pressure 4. reduces excitability and arrhythmia

Question 37

beta blockers contraindications (4)

Answer 37

asthma, cardiogenic shock, hypotension, AV block

Question 38

beta blocker side effects (5)

Answer 38

fatigue, cold extremities, bronchospasm, nightmares, impotence

Question 39

amiodarone MOA (3)

Answer 39

1. K+ channel blocker 2. extends action potential, delays repolarisation 3. blocks abnormal signals, arrhythmia

Question 40

amiodarone is first line use for (2)

Answer 40

SVT, VT

Question 41

amiodarone is given

Answer 41

IV

Question 42

calcium channel blockers are used in (3)

Answer 42

HTN, angina, arrhythmia

Question 43

calcium channel blockers MOA (2)

Answer 43

1. slows movement of calcium | 2. reduces HR, Lv contraction, BP

Question 44

calcium channel blockers contraindications (4)

Answer 44

pregnancy, cardiogenic shock, bradycardia, heart failure

Question 45

calcium channel blockers side effects (5)

Answer 45

low bp, slow HR, drowsiness, flushing, ankle oedema