Acute coronary syndrome

Question 1

What is the pathophysiology of ACS?

Answer 1

A thrombus from an atherosclerotic plaque blocking a coronary artery

Question 2

What is a thrombus in a fast flowing artery usually made up of?

Answer 2

Platelets

This is why anti-platelet medication is the mainstay of ACS treatment - aspirin, clopidogrel and ticagrelor

Question 3

What are the ECG leads corresponding to the heart areas and coronary vessels?

Answer 3

LCA - anterolateral - I, aVL, V3-V6
Circumflex - lateral - I, aVL, V5-V6
LAD - anteroseptal - V1-V4
RCA - inferior - I, II & avF

Question 4

What heart areas does the RCA supply?

Answer 4

Right atrium
Right ventricle
Inferior aspect of left ventricle
Posterior septal

Question 5

Which heart areas does the LCA supply?

Answer 5

Left atrium
Posterior aspect of left ventricle
Anterior aspect of left ventricle
Anterior aspect of septum

Question 6

Which heart areas does the LAD supply?

Answer 6

Anterior aspect of the left ventricle

Anterior aspect of septum

Question 7

What is the first investigation to perform when a patient presents with symptoms of ACS i.e. chest pain?

Answer 7

ECG

Question 8

Which ECG changes suggest a STEMI?

Answer 8

ST elevation or

New left bundle branch block

Question 9

Which ECG changes associated with NSTEMI?

Answer 9

ST depression
Deep T wave inversion
Pathological Q waves - suggests deep infarct & late sign

Question 10

If there is no ST elevation on ECG what is the next investigation to perform?

Answer 10

Troponin blood test

Question 11

If troponin is raised with other ECG signs e.g. ST depression, T wave inversion or pathological Q waves, what is the diagnosis?

Answer 11

NSTEMI

Question 12

If troponin is normal and no ECG changes, what is the likely diagnosis?

Answer 12

Likely unstable angina or MSK related chest pain

Question 13

What are the symptoms in ACS?

Answer 13

Central constricting chest pain associated with:
Nausea, vomiting
Sweating / clamminess
Sense of impending doom
Shortness of breath
Palpitations
Pain radiating to jaw or arms

Question 14

WRT troponins, a diagnosis of ACS requires?

Answer 14

Serial troponins - baseline, 6 and 12 hours

Question 15

What is troponin a sign of?

Answer 15

Myocardial ischaemia

Troponin is a protein released from ischaemic myocardium

Question 16

What are the five alternative causes of elevated troponin

Answer 16

Chronic renal failure
Sepsis
Myocarditis
Aortic dissection
PE

Question 17

What investigations would you perform in ACS

Answer 17

Physical examination (heart sounds, signs of HF, BMI)
ECG
FBC - look for anaemia
U&Es - baseline prior to starting ACEi 
LFTs - baseline prior to starting statins 
Lipid profile 
TFTs
HbA1c and fasting glucose

Chest xray to look for other causes of chest pain and pulmonary oedema
CT coronary angiogram to look for coronary artery disease
Echocardiogram to assess functional damage

Question 18

Management of acute STEMI?

Answer 18

PCI (presentation within 2 hours) - insertion of catheter into brachial or femoral artery to the coronary arteries and stenting/ balloon expansion/ clot removal with other devices

Thrombolysis - if presentation after 2 hours - injection of fibrinolytic medication –> streptokinase, alteplase, tenecteplase

Question 19

Acute NSTEMI treatment?

Answer 19

BATMAN
B - beta blockers unless contraindicated
A - aspirin 300mg stat dose
T - ticagrelor 180mg
M - morphine titrated to pain
A - anticoagulant - fondaparinux unless high bleeding risk
N - nitrates e.g. GTN

Question 20

What is the GRACE score used for?

Answer 20

To assess the need for PCI in NSTEMI

The 6 month risk of death or repeat MI following NSTEMI

Question 21

What does a GRACE score of 10% indicate?

Answer 21

<5% low risk
5-10% intermediate risk
>10% high risk

Intermediate to high risk are considered for early PCI within 4 days of admission for tx of coronary artery disease

Question 22

What are the complications of MI?

Answer 22

Death Passing PRAED St

Death: VF, LVF, CVA 
Pump failure 
Pericarditis 
Rupture - myomalacia cordis
Arrhythmias/ aneurysm
Embolism 
Dressler's syndrome: pleuro-pericarditis

Question 23

What is the secondary prevention lifestyle management?

Answer 23

Stop smoking 
Exercise 
Mediterranean diet 
Cardiac rehabilitation
Optimise control of other comorbidities e.g. diabetes and hypertension

Question 24

What is the secondary prevention medical management?

Answer 24

6 As
Aspirin 75mg once daily
Another antiplatelet: e.g. clopidogrel or ticagrelor for up to 12 months
Atorvastatin 80mg once daily
ACE inhibitors (e.g. ramipril titrated as tolerated to 10mg once daily)
Atenolol (or other beta blocker titrated as high as tolerated)
Aldosterone antagonist for those with clinical heart failure (i.e. eplerenone titrated to 50mg once daily)

Dual antiplatelet duration will vary following PCI procedures depending on the type of stent that was inserted. This is due to a higher risk of thrombus formation in different stents.

Question 25

Types of MI

Answer 25

Type 1: Traditional MI due to an acute coronary event
Type 2: Ischaemia secondary to increased demand or reduced supply of oxygen (e.g. secondary to severe anaemia, tachycardia or hypotension)
Type 3: Sudden cardiac death or cardiac arrest suggestive of an ischaemic event
Type 4: MI associated with PCI / coronary stunting / CABG