Myocardial Infarction

Question 1

High troponin can also indicate

Answer 1

kidney failure - check other renal function markers

Question 2

to rule out aortic dissection as a differential you should

Answer 2

check for radial/radial delay

check D-Dimer

Question 3

liver function tests in chest pain

Answer 3

cholangitis and pancreatitis can also cause chest pain

right sided heart failure can affect LFTs

Question 4

why do a Xray in chest pain

Answer 4

could show mediastinal enlargement (aortic dissection)

Question 5

questions to ask in suspected MI

Answer 5

pain (SOCRATES)
nausea
vomiting
SOB
sweating
palpitations
headaches
oedema
leg swelling (DVT)

Question 6

What does the term acute coronary syndrome mean?

Answer 6

umbrella term for spectrum of disease caused by ischaemia of myocardium

Question 7

what is the progression order of ACS?

Answer 7

Unstable angina -> NSTEMI -> STEMI

Question 8

what is unstable angina?

Answer 8

ischemia without infarction

Question 9

what is an NSTEMI?

Answer 9

non-ST elevation MI

Question 10

What is a STEMI?

Answer 10

ST elevation MI

Question 11

What are the non-modifiable risk factors of ACS?

Answer 11

age, male, HF of IHD (<55)

Question 12

what are the modifiable risk factors of ACS?

Answer 12

smoking, hypertension, diabetes, hyperlipidaemia, obesity, sedentary lifestyle

Question 13

what is the pathophysiology of ACS?

Answer 13

fibrous cap has an injury, thrombus forms on it, platelets adhere and cause clot

Question 14

What is the potential structural pathophysiology of the different ACS?

Answer 14

Unstable angina – unstable plaque
NSTEMI – not complete block (subendothelial infarct)
STEMI – complete block (transmural infarct)

Question 15

what further mechanism of injury di platelets cause?

Answer 15

• Platelets then release serotonin and thromboxane A2 and this causes vasoconstriction in the area resulting in reduced blood flow to the myocardium, and ischaemic injury.

Question 16

what are the clinical symptoms of ACS?

Answer 16

chest pain

Also sweating, breathless, syncope, tachycardia, reflux, vomiting and sinus bradycardia, distress, sudden death (VF)

Question 17

what are the features of chest pain in ACS?

Answer 17

radiates: inside left arm, neck and haw, epigastrium, back 
Cresendo pain
Central crushing chest pain 
lasts > 15 mins
exertional

Question 18

What are common symptoms of an atypical MI?

Answer 18

SOB, weakness, dizziness, syncope, pulmonary oedema, epigastric pain, vomiting, confusion, stroke, diabetic hyperglycaemia

Question 19

What are the suspicious symptoms of MI?

Answer 19

Pain lasting longer than 15mins in chest or other areas
Associated features (N+V, sweating, breathlessness)
Haemodynamic instability
New onset, or abrupt deterioration of stable angina

Question 20

What are the 3 key investigations for ACS?

Answer 20

• ECG
• Bloods: FBC, U&E, glucose, lipids
• Cardiac Enzymes: cardiac troponin, creatine kinase, myoglobin

Question 21

What are the diagnostic features of unstable angina?

Answer 21

o Troponin negative

o ECG – as for NSTEMI

Question 22

what are the diagnostic features of NSTEMI?

Answer 22

o A suggestive history
o Elevated troponin levels
o ECG changes

Question 23

What are the common ECG features of NSTEMI?

Answer 23

No ST elevation/normal
ST depression
Hyperacute T wave
T wave inversion
Non specific ST changes
absence of Q wave

Question 24

What are the diagnostic features of STEMI

Answer 24

o Raised Troponin

o ECG - ST elevation, LBBB, Q waves

Question 25

What are the criteria’s of ST elevations on ECG?

Answer 25

• ST elevation >1mm in 2 contiguous (consecutive) leads except V2 or V3
• ST elevation >2mm in V2 or V3 in men >45
• ST elevation >2.5mm in V2 or V3 in men <45
• ST elevation >1.5mm in V2 or V3 in women of any age

Question 26

What is the lifecycle of troponin during an MI?

Answer 26

Rise within 3-12hrs from onset of pain
Peak 24-48hrs
Return to baseline over 5-14 days

Question 27

Which leads show a lateral MI?

Answer 27

I, aVL, V5, V6

Question 28

Which leads show a inferior MI?

Answer 28

II, III, aVF

Question 29

Which leads show a Anterior MI?

Answer 29

V1, V2

Question 30

Which leads show a septal MI?

Answer 30

V3, V4

Question 31

What is the acute management of an MI?

Answer 31

MONA-T
o	Morphine – 5-10mg morphine + metoclopramide 10mg IV (antiemetic) 
o	Oxygen
o	Nitrates 
o	Aspirin 300mg aspirin
o	Ticagrelor

Question 32

What is the definitive management of STEMI?

Answer 32

PCI - balloon angioplasty or stenting
Thrombosis - streptokinase, recteplacse, or tenecteplase
B blocker
ACE inhibitor
consider Clopidogrel 200mg loading followed by 75mg/day for 30 days

Question 33

What is the definitive management of ACS without STEMI?

Answer 33

 B blocker
 Antithrombotic – fondaparinux (for 24hrs) or LMWH for 2-8 days
 Assess risk GRACE
 High Risk patients GPIIb/IIIa antagonist, or bivalidrium and angiography within 96hrs
 Clopidorgel in addition to aspirin for 12 months
 Low risk = clopidorgrel, discharge

Question 34

what are some post discharge life impacts for MI patients?

Answer 34

Discharged 5-7 days
return to work 2 months
Some professions no longer allowed 
Avoid sex 1 month
Avoid air travel 2 months

Question 35

What is the subsequent management of MI?

Answer 35

bed rest, thromboembolism prophylaxis, start a statin, cardiac rehabilitation, address modifiable risk factors

Question 36

What are the complications of ACS?

Answer 36

Cardiac arrest, bradycardia, heart block, tachyarrhythmias, LVF< RVF, pericarditis, DVT & PE, systemic embolus, cardiac tamponade, mitral regurg, ventricular septal defect, late malignant ventricular arrhythmias, Dressler’s syndrome, left ventricular aneurysm, mural thrombus, ventricular wall rupture, ventricular aneurysm, mitral valve imcomptence