ACS + AMI Therapy

Question 1

what is on the spectrum of acute coronary syndrome?

Answer 1

> unstable angina
non-ST elevated myocardial angina
ST-elevated myocardial angina
sudden cardiac death

Question 2

what is the gaol of therapy?

Answer 2

> increase myocardial oxygen supply

> decrease myocardial oxygen demand

Question 3

how is the myocardial oxygen supply increased?

Answer 3

through coronary vasodilation

Question 4

by what mechanisms is myocardial oxygen demand decreased?

Answer 4

> decrease in heart rate
decrease in blood pressure
decrease in preload or myocardial contractility

Question 5

how do thrombolytic agents work?

Answer 5

they are serine proteases that convert plasminogen to the natural fibrinolytic agent plasmin that lyses the clot by breaking down the fibrogen and fibrin .

Question 6

what two categories can fibrinolytics be divided into?

Answer 6

> fibrin specific agents

> non-fibrin specific agents

Question 7

name some fibrin specific agents

Answer 7

> alteplase
reteplase
tenecteplase

Question 8

name a non-fibrin specific agent and what does it catalyse?

Answer 8

streptokinase

systemic fibrinolysis

Question 9

give some contraindications for fibrinolysis

Answer 9

> prior intercranial haemorrhage
known structural cerebral vascular lesion
known malignant intracranial neoplasm
ischaemic stroke within 3 months
suspected aortic dissection
active bleeding/bleeding diathesis
significant closed-head trauma or facial trauma within three months

Question 10

what is the medical treatment protocol if there is no evidence of a STEMI?

Answer 10

> aspirin
> tigagrelor/clopidogrel
> fondaprinux/ light molecular weight heparin
> intravenous nitrate
> analgesia
> beta blocker

Question 11

what is the affect of statins on the athermatous plaque?

Answer 11

they stabilise it

Question 12

how does aspirin help reduce angina and MI?

Answer 12

it is a potent inhibitor of platelet thromboxane A2 production. thromboxane stimulates platelet aggregation and vasoconstriction. platelet aggregation is important to the development of angina and MI.

Question 13

what benefits can regular aspirin use have in acute MI?

Answer 13

> reduction of mortality by 23%

> in combination with thrombolysis reduce mortality by 42% and re-infarction by 52%

Question 14

what benefits can daily aspirin use have in unstable angina?

Answer 14

reduction in MI and death by 50%

Question 15

what are the secondary prevention effects of daily aspirin use?

Answer 15

reduction of re-infarction by 32% and combined vascular events by 25%

Question 16

what does clopidogrel inhibit?

Answer 16

> ADP receptor activated platelet aggregation

> irreversibly inhibits P2Y12 ADP receptor that is important in aggregation of platelets and cross-linking by fibrin

Question 17

what pathway does clopidogrel block?

Answer 17

the GP llb/llla pathway

Question 18

what is the llb/lla complex?

Answer 18

it is a receptor for fibrogen, fibronectin and von WF.

Question 19

what is the final common pathway for platelet aggregation and cross linkiung by fibrin?

Answer 19

activation of the llb/llla receptor complex

Question 20

what is clopidogrel used in combination with?

Answer 20

aspirin

Question 21

why are some people resistant to clopidogrel?

Answer 21

clopidogrel is activated by Cyp2C19. 14% of the population has low levels of Cyp2C19

Question 22

what does prasugrel inhibit?

Answer 22

ADP-induced platelet aggregation

Question 23

name four low molecular weight heparin drugs

Answer 23

> enoxaparin
dalteparin
tenzeparin
fondaparinux

Question 24

what is GPllb/llla?

Answer 24

it is an integrin complex found on platelets that is a receptor for fibrogen aids in platelet activation.

Question 25

what does platelet activation of gpllb/llla by ADP cause?

Answer 25

a conformational change in the receptor that induces the binding of fibrinogen.

Question 26

what is the major advesre affect of gllb/llla receptor blockers?

Answer 26

bleeding (minor and major). blood transfusion is required to terminate the bleeding and improve anaemia

Question 27

when are beta blocker used?

Answer 27

> treatment for acute MI

> secondary prevention in survivors of acute MI

Question 28

how do beta blockers reduce the myocardial oxygen consumption?

Answer 28

they competitively inhibit the myocardial effects of circulating catecholamine’s. this reduces the heart rate, blood pressure and myocardial contractility.