Myocardial Infarction

Question 1

What the risk factors for MI?

Answer 1

CAD 
Smoking 
Obesity 
HTN 
DM

Question 2

What are the symptoms of MI?

Answer 2

Acute central crushing chest pain (can radiate) 
Nausea
Sweating 
SOB 
Palpitations

Question 3

What are the signs of MI?

Answer 3

anxiety (feeling of doom) 
Pallor 
Sweating 
Pansystolic murmur 
change in HR or BP 
4th heart sound

Question 4

What are the investigations for suspected MI?

Answer 4

• ECG
• FBC, U&E, Glucose, lipids
• Cardiac enzymes (tropinin mainly but CK and myoglobin are other options)
• CXR

Question 5

What could an ECG within a couple of hours of an MI?

Answer 5

hyperacute tall T waves

ST elevation

New LBBB

ST depression and T wave inversion are less common

Question 6

What can an ECG show in the hours/days following an MI?

Answer 6

T wave inversion

Pathological Q waves

Question 7

What is a silent MI?

Answer 7

An usual presentation of MI which can be seen in the elderly and diabetics

Its features can include syncope, pulmonary oedema, epigastric pain, vomiting, acute confusion and diabetic hyperglycaemic states

Question 8

What is the immediate management of an MI?

Answer 8

Aspirin 300mg and clopidogrel 300mg

Morphine 5-10mg IV with antiemetic such as metoclopramide 10mg IV or cyclizine 50mg IV given with the first dose of morphine

Oxygen if Sa02 <95%, patient breathless or in acute LVF

Nitrates - GTN spray or sublingual tabs

B-blocker such as atenolol 5mg IV unless contraindicated. if contraindicated then give verapimil 100mg PO

Now assess if STEMI or NSTEMI

Question 9

In what situation are B-blockers contraindicated?

Answer 9

Asthma, COPD, LVF or bradycardia

Question 10

A STEMI has been diagnosed. What are the next steps?

Answer 10

Primary PCI

• if symptom onset <12 hours ago and pt has ongoing symptoms and persistent ST elevation on ECG
• Must be delievered within 120 mins of diagnosis
• balloon stenting

Fibrinolysis

• symptom onset <2-3 hours ago and PCI cannot be delievered within 120 mins
• administer within 10 mins of STEMI diagnosis
• Tenecteplase or alteplase
• arrange angiography and PCI within 2-24 hours

Give ACEi

Question 11

What are the contraindications for fibrinolysis?

Answer 11

Hx of stroke or haemorrhage 
Ischaemic stroke in last 6 months 
CNS damage or neoplasm 
Major trauma in last 6 months 
GI bleeding in last month 
Bleeding disorder

Question 12

An NSTEMI is diagnosed. What are the next steps?

Answer 12

B-blocker, atenolol 5mg IV

Anticoagulation
- Heparin, enoxaparin or fondaparineux

Assess risk using GRACE SCORE

• high risk then GPIIb/IIIa antangonist such as tirofiban and then angiography within 96 hours
• low risk = clopidogrel

Question 13

What is the subsequent managament of MI?

Answer 13

Bed rest for 48 hours with telemetry

thromboprophylaxis

Aspirin 75mg

Cardiac rehab - smoking cessation, weight loss, exercise, lipid modification

B-blocker

ACEi

Statin