Acute Coronary Syndrome

Question 1

Acute coronary syndrome?

Answer 1

Acute Coronary Syndrome is usually the result of a thrombus from an atherosclerotic plaque blocking a coronary artery

Question 2

Treatment acute coronary syndrome?

Why?

Answer 2

Anti-platelet medications such as aspirin, clopidogrel and ticagrelor are the mainstay of treatment

When a thrombus forms in a fast flowing artery it is made up mostly of platelets

Question 3

Name the coronary arteries?

Answer 3

Left coronary artery = becomes circumflex and LAD
RCA - supplies RA, RV, inferior LV, posterior septal area
Circumflex - supplies LA and posterior LV
LAD - supplies anterior LV and anterior septal area

Question 4

3 types of acute coronary syndrome?

Answer 4

Unstable Angina
ST Elevation Myocardial Infarction (STEMI)
Non-ST Elevation Myocardial Infarction (NSTEMI)

Question 5

When a patient presents with ACS symptoms (e.g. chest pain) what should you do?

Answer 5

When a patient presents with possible ACS symptoms (i.e. chest pain) perform an ECG:

If there is ST elevation or new left bundle branch block the diagnosis is STEMI.

If there is no ST elevation then perform troponin blood tests:

If there are raised troponin levels and/or other ECG changes (ST depression or T wave inversion or pathological Q waves) the diagnosis is NSTEMI

If troponin levels are normal and the ECG does not show pathological changes the diagnosis is either unstable angina or another cause such as musculoskeletal chest pain

Question 6

ACS symptoms?
How long should they last?
Exception?

Answer 6

Nausea and vomiting
Sweating and clamminess
Feeling of impending doom
Shortness of breath
Palpitations
Pain radiating to jaw or arms

Symptoms should continue at rest for more than 20 minutes.
If they settle with rest consider angina.

Diabetic patients may not experience typical chest pain during an acute coronary syndrome. This is often referred to as a “silent MI”.

Question 7

Which patients often experience a “silent MI”?

Answer 7

Diabetic patients

Question 8

ECG changes in STEMI?

Answer 8

ST segment elevation in leads consistent with an area of ischaemia
New Left Bundle Branch Block also diagnoses a “STEMI”

Question 9

ECG changes in NSTEMI?

Answer 9

ST segment depression in a region
Deep T Wave Inversion
Pathological Q Waves (suggesting a deep infarct – a late sign)

Question 10

Artery/heart area/ECG leads in ACS

Answer 10

Question 11

What are troponins?
Diagnosis?
Con?

Answer 11

Troponins are proteins found in cardiac muscle.

Diagnosis of ACS typically requires serial troponins (e.g. at baseline and 6 or 12 hours after onset of symptoms). A rise in troponin is consistent with myocardial ischaemia as the proteins are released from the ischaemic muscle

They are non-specific, meaning that a raised troponin does not automatically mean ACS.

Question 12

Other than MI, what can also cause a rise in troponins?

Answer 12

Chronic renal failure
Sepsis
Myocarditis
Aortic dissection
Pulmonary embolism

Question 13

Investigations for ACS?

Answer 13

Perform all investigations you would normally arrange for stable angina:-

ECG (+ troponins)
Physical exam (heart sounds, signs of heart failure, BMI)
FBC (check for anaemia)
U+Es (prior to ACEi and other meds)
LFTs (prior to statins)
Lipid profile
Thyroid function tests (check for hypo / hyper thyroid)
HbA1C and fasting glucose (for diabetes)

Plus:-

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

Question 14

Acute STEMI treatment?

Answer 14

Primary PCI (if available within 2 hours of presentation)
Thrombolysis (if PCI not available within 2 hours)

Question 15

What is PCI?

Thrombolysis?

Answer 15

Percutaneous Coronary Intervention (PCI) = putting a catheter into patient’s brachial or femoral artery, feeding it up to the coronary arteries under xray guidance and injecting contrast to identify the area of blockage. This can then be treated using balloons to widen the gap or devices to remove or aspirate the blockage. Usually a stent is put in to keep the artery open.

Thrombolysis = injecting a fibrinolytic medication (they break down fibrin) that rapidly dissolves clots. There is a significant risk of bleeding which can make it dangerous. Some examples of thrombolytic agents are streptokinase, alteplase and tenecteplase

Question 16

Acute NSTEMI treatment?

Answer 16

BATMAN

B - Beta blockers (unless contraindicated)
A – Aspirin 300mg stat dose
T – Ticagrelor 180mg stat dose (clopidogrel 300mg is an alternative if higher bleeding risk)
M – Morphine titrated to control pain
A – Anticoagulant: Fondaparinux (unless high bleeding risk)
N – Nitrates (e.g. GTN) to relieve coronary artery spasm

Give oxygen only if their oxygen saturations are dropping (i.e. <95%).

Question 17

What is used to assess need for PCI in NSTEMI?

Scores mean?

Answer 17

GRACE score

Gives a 6-month risk of death or repeat MI after having an NSTEMI:

<5% Low Risk
5-10% Medium Risk
>10% High Risk

If they are medium or high risk they are considered for early PCI (within 4 days of admission) to treat underlying coronary artery disease.

Question 18

Complications of MI?

Answer 18

DREAD

D – Death
R – Rupture of the heart septum or papillary muscles
E – “Edema” (Heart Failure)
A – Arrhythmia and Aneurysm
D – Dressler’s Syndrome

Question 19

What is Dressler’s syndrome?

Answer 19

Also called post-myocardial infarction syndrome - usually occurs around 2-3 weeks after an MI

It is caused by a localised immune response –> causes pericarditis (inflammation of the pericardium)

Question 20

Symptoms of Dressler’s syndrome?

Answer 20

Pleuritic chest pain
low grade fever
pericardial rub on auscultation

Question 21

Complications of Dressler’s syndrome?

Answer 21

It can cause a pericardial effusion and rarely a pericardial tamponade (where the fluid constricts the heart and prevents function)

Question 22

Diagnosis Dressler’s syndrome?

Answer 22

ECG (global ST elevation and T wave inversion)
Echocardiogram (pericardial effusion)
Raised inflammatory markers (CRP and ESR)

Question 23

Management Dressler’s syndrome?

Answer 23

Management is with NSAIDs (aspirin / ibuprofen)
and in more severe cases steroids (prednisolone)

May need pericardiocentesis to remove fluid from around the heart

Question 24

Secondary prevention MI?

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)

Also lifestyle changes - stop smoking, alcohol, Mediterranean diet, cardiac rehabilitation (specific exercise routine for patients post MI), optimise treatment of co-morbs e.g. diabetes