ACS

Question 1

Pathology of ACS

Answer 1

1. Irritant causes damage to endothelium of artery
2. LDL deposits
3. Monocytes > Macrophages that transform into foam cells
4. Plaque grows
5. Fibrous cap forms
6. Plaque ruptures
7. Blood clot forms

Question 2

Signs and symptoms of ACS

Answer 2

Collapse
Sweating
Pallor
Chest pain
Dyspnoea
Pulmonary oedema
Hypotensive
Brady/tachycardia
Nausea and vomiting
Pale and clammy

Question 3

Diagnosis of STEMI

Answer 3

History: Chest pain, Nausea and vomiting, Sweating
Occlusion: Complete thrombus occlusion causing severe cardiac damage
ECG: ST elevation
Troponin: High

Question 4

Diagnosis of Unstable angina

Answer 4

History: Angina at rest for more than 20 mins, increasing in frequency, no relief from GTN
Occlusion: Non occlusive thrombus
ECG: Normal
Troponin: Normal

Question 5

Diagnosis of NSTEMI

Answer 5

History: Angina at rest for more than 20 mins, increasing in frequency, no relief from GTN
Occlusion: Occluding thrombus sufficient enough to cause tissue damage and mild myocardial necrosis
ECG: Normal or ST depression and/or T inversion
Troponin: Slight elevation

Question 6

Troponin

Answer 6

It is a cardiac enzyme released during myocardial necrosis.

Question 7

Pre-hospital management

Answer 7

1. Pain (morphine 5-10mg iv)
2. May need anti-emetic (cyclizine or metoclopramide)
3. GTN sublingual
4. Aspirin 300mg chewed
5. 12 lead ECG
6. Assess oxygen and give oxygen is <94% (aim for 94-98%)

Question 8

Percutaneous coronary intervention

Answer 8

It is an emergency reperfusion to restore coronary flow and minimise myocardial injury - within 90 minutes of first medical contact.
Consists of placing a stent

Question 9

Secondary prevention of thrombosis in STEMI

Answer 9

Antiplatelets: Aspirin + Ticagrelor or Prasugrel (or clopidogrel)
Anticoagulants: Unfractionated heparin/LMWH/Bivalirudin

Question 10

STEMI fibrinolysis

Answer 10

Offered to patients within 12 hours of the onset of symptoms if PCI cannot be delivered within 120 minutes.
Antiplatelets: Aspirin + Clopidogrel (Ticagrelor and Pasugrel are not recommended)
Anticoagulant: LMWH

Question 11

NSTEMI/Unstable angina

Answer 11

> Single loading dose of 300mg Aspirin as soon as possible
Fondaparinux if angiography not likely within 24 hours of CrCl > 20mL/min
Unfractionated heparin if angiography likely within 24 hours, renal impairment

Question 12

Unfractionated heparin

Answer 12

Direct effect on thrombin
Monitor activated partial thromboplastin time
Renal function - <30mL/min

Question 13

LMWH

Answer 13

Titrated to body weight
Cause less thrombocytopenia
Contraindicated in poor renal function (<30mL/min)

Question 14

Long term-management

Answer 14

All patients who suffered acute MI require:
> Dual antiplatelet therapy (Aspirin + other)
> ACE inhibitor
> Beta blocker
> Statin

Question 15

ACE inhibitor/ARB

Answer 15

For:
> Cardiac remodelling
> Nephroprotection
> Treat and prevent heart failure

Question 16

Beta blocker

Answer 16

Alternative: calcium channel blocker (Diltiazem or verapamil)
Started as soon as possible as they decrease infarction size

Question 17

Statins

Answer 17

Atorvastatin 80mg
High doses for plaque stabilisation

Question 18

Gastroprotection

Answer 18

Lansoprazole 30mg for GI disturbances
Alternative: Ranitidine 300mg

Question 19

Hyperglycaemia

Answer 19

Upon hospital administration, should be kept 11mmol/L using a dose adjusted insulin.

Hyperglycaemia after ACS without known diabetes should be tested for HbA1c levels.

Question 20

Other notes

Answer 20

NSAIDs should be stopped