ELM13: Acute coronary syndromes

Question 1

What are ACS?

Answer 1

Disorders with chest pain that radiates
Not relived by rest
Caused by coronary artery thrombosis Involve cardiac ischaemia

Question 2

What are the three main categories of ACS?

Answer 2

Unstable angina
NSTEMI
STEMI

Question 3

What is the pain treatment for ACS?

Answer 3

Opiods

Question 4

What is the treatment to reduce cardiac workload and improve blood supply in ACS?

Answer 4

Beta blocker
GTN

Question 5

What is the treatment to prevent further thrombosis in ACS?

Answer 5

Aspirin
Ticagrelor
Heparins

Question 6

What are the treatments for reperfusion in ACS?

Answer 6

PCI
CABG
Thrombolysis

Question 7

What is haemostasis?

Answer 7

Preventing blood loss after vessel damage
Coagulation platelet aggregation and vasoconstriction

Question 8

What is thombosis?

Answer 8

Pathological
DVT
Embolism
Stroke
Heart attack

Question 9

What is a thrombus?

Answer 9

A pathogenic blood clot attached to cell wall
Traps platelets and blood cells

Question 10

What has a major role in venous thrombosis?

Answer 10

Coagulation

Question 11

What has a major role in arterial thrombosis?

Answer 11

Platelet aggregation

Question 12

What is an embolus?

Answer 12

Complication of a thrombus
Part or whole detaches from wall and travels through vessels
Causes blockage

Question 13

What is the main aim of drugs treating thrombus?

Answer 13

Inhibit formation without preventing haemostasis

Question 14

What are the three main targets of modifying the thrombosis process?

Answer 14

Modify coagulation
Modify platelet aggregation
Modify clot thrombus breakdown

Question 15

What are heparins in relation to thrombosis?

Answer 15

Modify coagulation to prevent thrombosis

Question 16

Where are heparins found?

Answer 16

Liver
Lungs
Mast cells

Question 17

What is the role of heparins?

Answer 17

Inhibit action of thrombin and factors Xa and IXA
Increases rate of formation of antithrombin III thrombin complex

Question 18

What is required for heparins to work?

Answer 18

Antithrombin III
Factor IIA

Question 19

What are some other actions of heparins?

Answer 19

Reduce platelet aggregation
Reduces platelet numbers
Influences lipid metabolism

Question 20

What are some clinical uses of heparins?

Answer 20

Venous thrombosis and embolism
After heart attack or stroke
Reduce DVT risk after orthopaedic surgery

Question 21

What is thrombin?

Answer 21

Proteolytic enzyme
Converts fibrinogen to fibrin

Question 22

How is actin thrombin formed?

Answer 22

Cleavage of prothrombin by factor Xa

Question 23

What is fondaparinux?

Answer 23

Synthetic sulphated mucopentasaccharide
Similar action to LMW heparins with less side effects

Question 24

What are some issues with heparins?

Answer 24

Not absorbed orally
Allergic reactions
Individualised dose
Haemorrhage risk

Question 25

How is warfarin administered?

Answer 25

Orally

Question 26

What is warfarin usually used for?

Answer 26

Venous thrombo embolism Stroke prevention

Question 27

How does warfarin work?

Answer 27

Similar structure to vitamin K Antagonises its role in some clotting factors

Question 28

What are some problems with warfarin?

Answer 28

Slow onset Activity influenced by vitamin K Exists as R S isomers Haemorrhage risk Teratogenic

Question 29

What drug is a direct inhibitor of thrombin?

Answer 29

Dabigatran

Question 30

What drug is an inhibitor of factor Xa?

Answer 30

Rivaroxaban

Question 31

What are the benefits of using newer drugs like dabigatran and rivaroxaban as treatment?

Answer 31

Don't need monitoring 'Easier to use

Question 32

What are platelets?

Answer 32

Derived from megakaryocytes Fragments of cytoplasm with no nucleus

Question 33

What are some stimuli of platelet aggregation and activation?

Answer 33

ADP TxA2 Thrombin

Question 34

What is the role of TxA2 in platelet aggregation and adhesion?

Answer 34

1. Synthesised from arachidonic acid by cyclo-oxygenase 2. Activated platelets synthesise TxA2 3. Released from platelets and increases levels of IIb and IIa receptors

Question 35

What is the process of inhibition of aggregation?

Answer 35

Endothelium releases prostacyclin

Question 36

What is the first mechanism of antiplatelet drugs using aspirin?

Answer 36

1. Irreversibly blocks platelet COX enzyme 2. Reduces TxA2 synthesis

Question 37

W hat are some unwanted side effects of aspirin?

Answer 37

Extended bleeding time Indigestion Allergy Asthma attacks Reyes

Question 38

What is the second mechanism of antiplatelet drugs?

Answer 38

Modulating expression of glycoprotein IIb/a receptors

Question 39

What is an example of a drug using the second mechanism?

Answer 39

Clopidogrel Inhibits glycoprotein IIa/b expression on platelets Blocks ADP receptor irreversibly

Question 40

What was the PLATO trial?

Answer 40

Compared clopidogrel with ticagrelor Ticagrelor superior

Question 41

What are some unwanted side effects of clopidogrel and ticagrelor?

Answer 41

Extended bleeding time GI tract problems Headaches Gout T Breathless ness T

Question 42

What is the third mechanism of antiplatelet drugs?

Answer 42

Raise cAMP levels

Question 43

What is an example of a drug using the third mechanism?

Answer 43

Dipyridamole Phosphodiester inhibitor that prevents cAMP breakdown in platelets

Question 44

What are some side effects of dipyridamole?

Answer 44

GI tract problems Headaches Muscle pain Flushing

Question 45

What are some treatments causing reperfusion?

Answer 45

PCI CABG Thrombolysis

Question 46

What are some properties of PCI?

Answer 46

Rapid Safe Specialist centre

Question 47

What are some properties of thrombolysis?

Answer 47

Very rapid Risky Little equipment