Acute MI

Question 1

How do platelets initiate the build up of atheromatous plaques?

Answer 1

They form a monolayer and initiate a cascade which causes platelet clumping to attract other platelets

Question 2

What do platelets release when they are activated?

Answer 2

ADP and thromboxane A2 through the cyclooxygenase system

Question 3

What is produced at the end of the clotting process?

Answer 3

A thrombus

Question 4

What is the first effect of the build-up of plaque?

Answer 4

Stable angina- a fixed stenosis which results in a demand led ischaemia that is usually predictable and safe

Question 5

Does pain from angina radiate?

Answer 5

Yes often down the left arm as well as other sites

Question 6

What is the second effect of the build-up of plaque?

Answer 6

Acute coronary syndrome- a dynamic stenosis with a supply led ischaemia which is unpredictable and dangerous

Question 7

What are important factors in determining the cause of a plaque rupture?

Answer 7

Thickness of the fibrous cap ad lipid content of plaque

Question 8

Are old or new plaques more likely to rupture?

Answer 8

New

Question 9

What other factors can increase the risk of a plaque rupture?

Answer 9

Bending of an artery or sudden change in intra-luminal pressure

Question 10

What occurs when a coronary artery is completely occluded?

Answer 10

STEMI

Question 11

What will a STEMI ultimately lead to?

Answer 11

Heart failure

Question 12

What are some symptoms of heart failure?

Answer 12

Breathless, cough, PND, orthopnoea,

Question 13

What is typical STEMI pain?

Answer 13

Central crushing chest pain radiating to arm and jaw, similar to angina but worse and not relieved by GTN

Question 14

What are some associated symptoms of a STTEMI?

Answer 14

Sweating, nausea and vomiting

Question 15

What are non-cardiac differentials of STEMI?

Answer 15

Pneumothorax (sudden), pleuritic pain of pneumonia, MSK pain or heartburn

Question 16

What is the first ECG change to occur in a STEMI?

Answer 16

ST elevation

Question 17

What ECG changes may show a bit later on a STEMI?

Answer 17

T wave inversion or Q waves

Question 18

What are Q waves?

Answer 18

Downward deflections between the p wave and QRS

Question 19

What are the rules with regards to ST elevation?

Answer 19

ST elevation must be 1cm or greater in 2 adjacent limb leads or 2cm or greater in 2 contiguous precordial leads (or new onset LBBB)

Question 20

What leads and artery are involved in an inferior MI?

Answer 20

II, III, aVF

Right coronary artery

Question 21

What leads and artery are involved in an anteroseptal MI?

Answer 21

V1-4

Left anterior descending artery

Question 22

What leads and artery are involved in an anterolateral MI?

Answer 22

I, aVL, V4-6

Left anterior descending or left circumflex

Question 23

What leads and artery are involved in an lateral MI?

Answer 23

I, aVL +/- V5-6

Left circumflex artery

Question 24

What does a posterior MI show and what artery is involved?

Answer 24

Tall r waves in V1-2

Left circumflex or right coronary artery

Question 25

What are further diagnostic tools used for STEMI?

Answer 25

Cardiac enzymes (troponin) and protein markers

Question 26

What is the downside of cardiac enzymes and protein markers?

Answer 26

Might take too long to wait for results

Question 27

What anti-platelet drugs are used for STEMI and how do they work?

Answer 27

Aspirin- switches off cyclooxygenase system to block thromboxane A2 Clopidogrel- blocks ADP receptors Ticagrelor or prasugrel can be used instead of clopidogrel

Question 28

How much aspirin and clopidogrel is given?

Answer 28

300mg

Question 29

When is clopidogrel given?

Answer 29

Once there are ECG changes or elevation of cardiac markers to back up your diagnosis

Question 30

How can patients be re-perfused?

Answer 30

Thrombolysis (streptokinase) or PCI (preferred)

Question 31

When should patients receive thrombolysis?

Answer 31

If PCI cannot be carried out within 90 mins of diagnosis

Question 32

What should happen to patients after receiving thrombolysis?

Answer 32

Coronary angiography or emergency angioplasty

Question 33

What is the step by step treatment of STEMI?

Answer 33

``` Analgesia (IV diamorphine) Anti-emetic (IV metoclopramide) Aspirin and clopidogrel GTN (if BP >90mmHg) Oxygen if hypoxic PCI or thrombolysis ```

Question 34

What medications should patients be put on following a STEMI?

Answer 34

Beta blocker, ACE inhibitor, statin and dual antiplatelet therapy (aspirin for life, other for less)

Question 35

Patients with heart failure can also be put on what drug long term?

Answer 35

Aldosterone antagonists- spironolactone

Question 36

What lifestyle advice should patients be given following a STEMI?

Answer 36

Stop smoking, cut down alcohol, advice better diet (lots of omega 3), exercise 20-30 mins a day

Question 37

What are the rules regarding sex after an MI?

Answer 37

Can resume after four weeks and will have no effect on future MIs

Question 38

What advice should be given about driving following MI?

Answer 38

4 weeks until you start again and no need to tell DVLA (car/bike) 6 weeks until you start again and do need to tell the DVLA (large vehicle)

Question 39

What is the main arrhythmic complication of a STEMI? How is it treated?

Answer 39

VF- defibrillation

Question 40

What are structural complications after a STEMI?

Answer 40

Cardiac rupture, VSD, mitral regurgitation with papillary muscle damage, left ventricular aneurysm, pericarditis/Dressler's syndrome

Question 41

Which STEMI complication would cause recurrent chest pain and shock, low BP and CO?

Answer 41

Ventricular septal defect

Question 42

What complication of a STEMI can present as pulmonary oedema?

Answer 42

Mitral regurgitation

Question 43

What complication of a STEMI will give persistent ST elevation and LV failure?

Answer 43

Left ventricular aneurysm

Question 44

What is Dressler's syndrome?

Answer 44

An autoimmune condition cause pericarditis 2-10 weeks post MI

Question 45

What complications could a new heart sound suggest?

Answer 45

VSD or mitral regurgitation

Question 46

What can all STEMI complications lead to?

Answer 46

Acute or chronic heart failure and possible cardiogenic shock

Question 47

What is the difference in pathogenesis of NSTEMI?

Answer 47

Artery is not completely occluded

Question 48

How is complete occlusion prevented in NSTEMI?

Answer 48

By our bodies own thrombolysis- plasmin

Question 49

What is the main feature of an NSTEMI?

Answer 49

Chest pain

Question 50

What is the most important thing to remember about an NSTEMI?

Answer 50

ECG may be normal

Question 51

What can an ECG of NSTEMI show?

Answer 51

ST depression or T wave inversion

Question 52

What is a type II MI?

Answer 52

Not caused by a rupture of a plaque but instead by an imbalance of oxygen supply and demand

Question 53

How is the coagulation cascade blocked in NSEMI?

Answer 53

LMWH

Question 54

What can be used to prevent progression of NSTEMI to STEMI?

Answer 54

2b3a inhibitors

Question 55

Patients who are at high risk with identifiable troponin should undergo what?

Answer 55

Coronary angiography and revascularisation

Question 56

What should long term therapy be for NSTEMI?

Answer 56

Aspirin (life) and clopidogrel (3 months)

Question 57

What should a patients target cholesterol and BP be following an NSTEMI?

Answer 57

<4mmol/l and <140/85