myocardial infarction

Question 1

what 3 things does acute coronary syndromes include

Answer 1

• STEMI
• NSTEMI
• unstable angina

Question 2

what is difference between MI and angina

Answer 2

in MI there is occluding thrombus which leads to myocardial necrosis and a rise in serum troponins or creatine kinase

Question 3

when does MI occur

Answer 3

when cardiac myocytes die due to myocardial ischaemia

Question 4

how can MI be diagnosed

Answer 4

• appropriate clinical history
• ECG
• elevated biochemical markers (troponin, CK)

Question 5

when should MI term be used

Answer 5

when there is evidence of myocardial necrosis in clinical setting

Question 6

how many types of MI are there

Answer 6

5

Question 7

what mechanism causes all ACS

Answer 7

rupture or erosion of the fibrous cap of a coronary artery plaque

Question 8

what does rupture of platelet plaque lead to

Answer 8

• platelet aggregation and adhesion
• localised thrombosis
• vasoconstriction
• distal thrombus embolisation

Question 9

what platelets cause vasoconstriction

Answer 9

• serotonin

- thromboxane A2

Question 10

why does ischaemia occur

Answer 10

reduction of coronary blood flow

Question 11

symptoms

Answer 11

• chest pain at rest
• indigestion
• pleuritic chest pain
• dyspnoea

Question 12

what does ECG show

Answer 12

• ST depression

- T wave inversion

Question 13

what does a complete occlusion of coronary vessel show on ECG

Answer 13

ST elevation

Question 14

where is troponin located

Answer 14

with tropomyosin on the thin actin filament

Question 15

what troponin attaches tropomyosin

Answer 15

T

Question 16

what does troponin C bind

Answer 16

calcium during excitation-contraction coupling

Question 17

what does troponin I inhibit

Answer 17

the myosin binding site on the actin

Question 18

what does increased troponin mean

Answer 18

higher mortality rate in ACS

Question 19

what is a standard marker for myocyte death

Answer 19

CK

Question 20

is CK accurate

Answer 20

no

Question 21

what is CK better at determining

Answer 21

re-infarction

Question 22

what becomes elevated very early in MI

Answer 22

myoglobin

Question 23

is myoglobin specific

Answer 23

no

Question 24

what does ECG show for NSTEMI

Answer 24

• ST depression

- dynamic ST changes

Question 25

what are risk factors for NSTEI

Answer 25

- age - prior MI - bypass surgery - diabetes - heart failure

Question 26

what is used to diagnose NSTEMI

Answer 26

- raised troponin | - ECG

Question 27

whats done first for NSTEMI

Answer 27

PCI (within 2 hours)

Question 28

what drugs are given for support (MI)

Answer 28

- aspirin - anti-plattelet - anti thrombotic (LMWH) - oxygen (if hypoxic)

Question 29

what is given to patient for sickness

Answer 29

opiates + GTN

Question 30

what does rupture of atheromatous plaque expose

Answer 30

the circulating platelets to ADP, thromboxane A2, adrenaline, thrombin and collagen tissue factor

Question 31

what does platelet activation stimulate

Answer 31

the expression of glycoprotein IIb/IIIa receptor on platelet surface

Question 32

what antiplatelet therapy should ACS patients be given

Answer 32

dual platelet therapy aspirin and an ADP-receptor antagonist (clopidogrel or prasugrel or tricagrelor)

Question 33

what else should be added to the antiplatelet therapy

Answer 33

antithrombin

Question 34

what drug is given to reduce myocardial ischaemia

Answer 34

beta blocker

Question 35

how do beta blocker reduce myocardial ischaemia

Answer 35

by blocking circulating catecholamines lower heart rate and blood pressure

Question 36

what drug blocks HMG CoA reductase

Answer 36

statins

Question 37

what additional 2 drugs are routinely administered

Answer 37

- statins | - ACE inhibitors

Question 38

what are single vessel lesions are treated with

Answer 38

PCI

Question 39

why does myocardial infarction occur

Answer 39

when cardiac myocytes die due to prolonged myocardial ischaemia

Question 40

how long does it take for myocardial necrosis to occur

Answer 40

15-30 minutes

Question 41

how long would chest pain last before you come concerned about MI

Answer 41

20 minutes

Question 42

does STEMI chest pain respond to sublingual glycerol trinitrate

Answer 42

no

Question 43

where can the pain radiate in STEMI

Answer 43

to the left arm, neck or jaw

Question 44

what are other symptoms that can occur in elderly

Answer 44

- dyspnoea - fatigue - pre-syncope - syncope

Question 45

what are other common symptoms of STEMI

Answer 45

- pale - clammy - marked sweating - thready pulse - hypotension - bradycardia/tachycardia

Question 46

what ECG leads are affected in STEMI

Answer 46

those facing the infarction

Question 47

what ECG changes are evident in STEMI

Answer 47

ST elevation (due to opening of K channels)

Question 48

what leads have ST elevation in anterior STEMI

Answer 48

II III AVF

Question 49

what leads have ST elevation in later STEMI

Answer 49

I AVL V5 V6

Question 50

what leads have ST elevation in poster STEMI

Answer 50

ST depression V1-V3 ST elevation in V5-V6

Question 51

ST elevation in V3-V4 is where

Answer 51

anterior

Question 52

ST elevation in V1-V3 is where

Answer 52

anteroseptal

Question 53

``` ST elevation in: V4-V6 AVL I is where ```

Answer 53

anterolateral

Question 54

ST elevation in I AVL is where

Answer 54

latteral

Question 55

``` ST elevation in: II III AVF is where ```

Answer 55

inferior

Question 56

ST elevation in: | V1-V2 is where

Answer 56

posterior

Question 57

what imaging can be helpful in STEMI

Answer 57

transthoracic echocardiography

Question 58

what has to be done quickly once patient diagnosed with STEMI

Answer 58

PCI or thrombolysis

Question 59

what is the initial medical therapy given for STEMI

Answer 59

- oxygen - morphine (opioids) - aspirin MONA + C

Question 60

what is the time frame for PCI

Answer 60

90 minutes

Question 61

what should patients undergoing primary PCI be given in STEMI

Answer 61

- dual antiplatelet - aspirin - ADP-receptor blocker (e.g. prasugrel or tricagrelor)

Question 62

what do fibrinolytics enhance

Answer 62

the breakdown of occlusive thromboses by the activation of plasminogen. to form plasmin

Question 63

what can be used if PCI unavailable in STEMI

Answer 63

fibrinolysis (thrombolysis) can prevent death

Question 64

when is cardiac artery bypass surgery usually done in STEMI

Answer 64

for complications of MI

Question 65

complications

Answer 65

- heart failure - mitral regurgitation - ventricular arrhythmia - heart block - rupture - dresslers syndrome

Question 66

what can heart failure caused by MI respond to

Answer 66

IV furosemide

Question 67

what is required for heart failure treatment

Answer 67

oxygen

Question 68

what is an early fatal event that can happen post MI

Answer 68

ventricle rupture

Question 69

how can you repair a minor rupture

Answer 69

pericardiocentesis followed by surgical repair

Question 70

what valvular disease can occur post MI

Answer 70

mitral regurgitation

Question 71

what does cardiac arrest require

Answer 71

defibrillation

Question 72

what should ventricular tachycardia post MI be treated with

Answer 72

beta blocker lidocaine or amiodarone

Question 73

treatment of post MI AF

Answer 73

beta blockers + digoxin

Question 74

what is treatment for heart blocks post MI

Answer 74

permanent pacing

Question 75

post-MI lifestyle modifications

Answer 75

- exercise programme - dietary recommendations (increase veggies, reduce salt) - reduce alcohol - stop smoking - maintain a healthy weight - reduce blood pressure (if high) - regulate patients with diabetes

Question 76

post MI drug therapy

Answer 76

- aspirin - ADP-receptor blocker - oral beta blocker (maintain heart rate) - ACE inhibitors / ARB - statins - aldosterone antagonist

Question 77

whats preferred PCI or thrombolysis

Answer 77

PCI