MI

Question 1

what is chronic stable angina?

Answer 1

fixed stenosis
demand led ischaemia
predictable
safe

Question 2

what to do in chronic stable angina?

Answer 2

stop
sit
spray

Question 3

what is an acute coronary syndrome?

Answer 3

any acute presentation of coronary artery disease

only a provisional diagnosis that covers a spectrum of conditions

Question 4

describe acute coronary syndrome

Answer 4

unstable angina
dynamic stenosis
supply led ischaemia 
unpredictable 
dangerous

Question 5

what are the factors affecting plaque rupture?

Answer 5

lipid content of plaque
thickness of fibrous cap
sudden changes in intraluminal pressure or tone
bending and twisting of an artery during each heart contraction
plaque shape
mechanical injury

Question 6

describe initiation of platelet cascade

Answer 6

vascular damage
- percutaneous coronary interventions 
exposed tissue elements
- subendothelial collagen 
- von willebrand factor

Question 7

describe adhesion during platelet cascade

Answer 7

platelet recruitment and adhesion at the site of injury forming a monolayer

Question 8

describe the release of activators during platelet cascade

Answer 8

ADP and other activators are released through degranulation

thromboxane A2 is generated via cycloxygenase

Question 9

what are the surface receptors during platelet cascade?

Answer 9

ADP receptors

Question 10

describe the amplification of platelet activation

Answer 10

platelet activation accelerates resulting in platelet aggregation

Question 11

what does the activation of the platelet cascade trigger?

Answer 11

an inflammatory cascade as activated platelets express adhesion receptors for leukocytes

Question 12

what is the pathway to platelet aggregation?

Answer 12

activator release
aggregation
inflammation
vascular blockage 
acute MI, stroke or death

Question 13

what is the history of someone with an MI?

Answer 13

severe crushing central chest pain
radiating to jaw and arms, especially the left
similar to angina but more severe, prolonged and not relieved by GTN
associated with sweating, nausea and often vomiting

Question 14

what are the ECG changes in STEMI?

Answer 14

ST elevation
T wave inversion
Q waves

Question 15

how to differentiate a STEMI?

Answer 15

> 1mm ST elevation in 2 adjacent limb leads
2mm ST elevation in at least 2 contiguous precordial leads
new onset bundle branch block

Question 16

what are the evolving ECG changes of a STEMI?

Answer 16

ST elevation- first few hours
Q wave formation and T wave inversion- first day
Old MI- Q waves and sometimes inverted T waves

Question 17

where to spot an inferior MI on an ECG?

Answer 17

II, III, AVF

Question 18

where to spot an anterior MI on an ECG?

Answer 18

V1-V6

Question 19

where to spot an anteroseptal MI on an ECG?

Answer 19

V1-V4

Question 20

where to spot an anterolateral MI on an ECG?

Answer 20

I, AVL, V1-V6

Question 21

what else can be used in the diagnosis of an MI?

Answer 21

cardiac enzymes and protein markers but they may be normal at presentation

Question 22

what is the enzyme that can be used in the diagnosis of an MI?

Answer 22

creatinine kinase

peaks in 24 hours

Question 23

what is the protein marker that can be used in the diagnosis of an MI?

Answer 23

troponin
highly specific for cardiac muscle damage
can detect tiny amounts of myocardial necrosis

Question 24

how do you treat a STEMI?

Answer 24

early 
analgesis- diamorphine IV
anti-emetic- IV
aspirin and clopidogrel
GTN if BP >90
oxygen if hypoxic 
primary angioplasty 
thrombolysis if angioplasty not available within 90 mins

Question 25

what are the indications for repurfusion therapy?

Answer 25

chest pain suggestive of acute myocardial infarction
ECG changes
no contraindications

Question 26

what is repurfusion therapy?

Answer 26

thrombolysis or PCI

Question 27

what is chest pain suggestive of acute myocardial infarction?

Answer 27

more than 20 mins

less than 12 hours

Question 28

what are the risks of thrombolytic therapy?

Answer 28

failure to re-perfuse
haemorrhage
hypersensitivity

Question 29

what are the complications of an MI?

Answer 29

death
arrythmic complications
structural complications
functional complications

Question 30

what is the usual arrythmic complication of an MI?

Answer 30

ventricular fibrillation

Question 31

what are the structural complications of an MI?

Answer 31

cardiac rupture 
ventricular septal defect 
mitral valve regurgitation
left ventricular aneurysm formation 
mural thrombus with or without systemic emboli 
inflammation 
acute pericarditis 
dressler's syndrome

Question 32

what are the functional complications of an MI?

Answer 32

acute ventricular failure
chronic cardiac failure
cardiogenic shock

Question 33

what system is used to classify in-hospital mortality?

Answer 33

killip classification

Question 34

what is I?

Answer 34

no signs of heart failure

6%

Question 35

what is II?

Answer 35

crepitations < 50% of lung fields

17%

Question 36

what is III?

Answer 36

crepitations > 50% of lung fields

38%

Question 37

what is IV?

Answer 37

cardiogenic shock

81%

Question 38

what are the ECG changes in an NSTEMI?

Answer 38

may be normal

Question 39

what can be used to diagnose an MI?

Answer 39

troponins

Question 40

what are the typical features of an NSTEMI?

Answer 40

less chest pain
minor ECG changes
tach/low BP/ illness
smaller more static trop

Question 41

what are the typical features of an NSTEMI?

Answer 41

less chest pain
minor ECG changes
tach/low BP/ illness
smaller more static trop