Acute Coronary Syndrome/ACS (1*)

Question 1

What is this?

What are its 3 types?

What are its non-modifiable risk factors?

What are its modifiable risk factors?

Answer 1

➊ Signs and symptoms resulting from impaired cardiac perfusion at rest

➋ • STEMI - full-thickness infarction (complete occlusion)
• NSTEMI - mid-thickness infarction (partial occlusion)
• Unstable Angina - no infarction (partial occlusion)

➌ Age, Gender, Family hx

➍ Smoking, HTN, DM, Hyperlipidaemia, Obesity, Sedentary lifestyle

Question 2

How does it present?

What are the atypical ways in which it can present?
→ Who is this more common in?

What are the other differentials for chest pain?

Answer 2

➊ • Central, crushing chest pain that radiates to jaw/neck/left arm
• Worsened by exercise/exertion and may be improved by GTN
• Associated symptoms - N+V, Sweating, Clamminess, SOB

➋ • Epigastric pain
• No pain (Silent MI)
→ Elderly and Diabetics

➌ • Cardiac - Angina, Aortic dissection, Myocarditis, Pericarditis
• Pulmonary - PE, Pneumonia, PTX (pleuritic pain)
• GI - Oesophagitis, GORD, Peptic ulcer, Pancreatitis, Cholecystitis
• MSK - Costochondritis, Rib fracture

Question 3

Investigations:
What’s the immediate investigation to do?
→ Why is this so important?

What else should be done?

What is Troponin?
→ When else would it be raised?

How is Unstable Angina diagnosed?

Answer 3

➊ ECG
→ • Defines immediate management
• If it shows STEMI, then troponin is essentially irrelevant and the patient will require immediate treatment

N.B. ST elevation is a sign of infarction, whereas ST depression is a sign of ischaemia

➋ • Troponin
• Bloods - FBC, U&Es, LFTs, Lipids, Glucose
• CXR - Check for pulmonary causes of chest pain
• Echo - Assess for functional damage
• CT Coronary Angiogram

N.B. Myoglobin is the first biomarker raised after an MI

N.B. If a pt, who has recently had a PCI w/stenting done, presents with new chest pain, you need to do a CK-MB as they’ve most likely re-stenosed the stent

➌ Protein released from damaged cardiac myocytes - Typically raised 3 hrs post-MI
→ Pericarditis, Myocarditis, Type A Aortic dissection, PE, CKD, Sepsis, Prolonged strenuous exercise

➍ Chest pain + abnormal/normal ECG + normal troponin

Question 4

ECG Changes:
Which area of the heart is affected if there’s STE in Leads II, III, aVF?
→ Which artery supplies this area?

Which area of the heart is affected if there’s STE in Leads I, aVL, V5-6?
→ Which artery supplies this area?

Which area of the heart is affected if there’s STE in Leads V1-4?
→ Which artery supplies this area?

What would be expected in a posterior STEMI?

Answer 4

➊ Inferior
→ Right CA

➋ Lateral
→ Left Circumflex CA

➌ Anteroseptal
→ LAD

➍ ST depression in reciprocal chest leads (V1-3)

Question 5

STEMI:
How is it diagnosed?
→ What does the STE have to be here?

What’s the first thing to do if suspected?

What is the mainstay of treatment?

How is it managed medically?

Answer 5

➊ Cardiac chest pain + ST-elevation/new LBBB (no need for a troponin in this case)
→ * 2mm in adjacent chest leads
* >1mm in adjacent limb leads

➋ Assess if the pt is eligible for reperfusion therapy (PCI or fibrinolysis)

➌ PCI if presenting < 12 hrs from symptom onset and can be given in under 120 mins

➍ * Loading dose of PO Aspirin 300mg
‣ If eligible for PCI, add Prasugrel (if not on anti-coags) or Clopidogrel (if on anti-coags)
‣ If not eligible for PCI, add Ticagrelor
* IV Morphine/diamorphine - in addition to pain relief, this causes vasodilation, therefore reducing preload
* IV GTN infusion - for symptomatic relief

N.B. When morphine is given IV, it acts as a strong emetic agent, therefore pts are commonly co-prescribed an anti-emetic

Question 6

NSTEMI:
How is it diagnosed?

What’s the first thing to do if suspected?
→ What does this indicate?

What is the mainstay of treatment?

How else is it managed?

What score is used here?
→ What does it indicate?

Answer 6

➊ Chest pain + abnormal/normal ECG (no STE) + raised troponin

N.B. ST-depression as part of an NSTEMI is generally poorly localised, whereas a posterior STEMI will produce localised ST-depression in the anterior leads (V1-V3).

➋ Calculate the GRACE score
→ 6-month mortality and risk of cardiovascular events

➌ Treatment dose LMWH or Fondaparinux

➍ * Loading dose of PO Aspirin 300mg
‣ Those with a higher GRACE score should be given Prasugrel or Ticagrelor instead
* Sublingual GTN spray - for symptom relief
* IV Morphine/diamorphine - in addition to pain relief, this causes vasodilation, therefore reducing preload

N.B. When morphine is given IV, it acts as a strong emetic agent, therefore pts are commonly co-prescribed an anti-emetic

N.B. Treatment for unstable angina is similar to this

Question 7

Post-MI Management:
What are the lifestyle changes to make?

What should all pts be started on?

What should be done on the pt? Why?

Answer 7

➊ • Smoking cessation
• Reducing alcohol
• Weight loss
• Diet
• Better diabetic/pressure control

➋ BAAD:
• B-blocker (usually Bisoprolol)
• ACEi (usually Ramipril)
• Atorvastatin 80mg
• Dual Antiplatelet therapy (Aspirin 75mg + Clopidogrel/Ticagrelor)

N.B. Use Simvastatin in those on ART.

➌ Echo to assess systolic function and for evidence of heart failure

Question 8

What are the complications that can occur?

Answer 8

• Cardiac Tamponade
‣ Due to rupture of ventricular free wall, presenting with cardiac arrest
• Acute Mitral Regurgitation
‣ Due to rupture of papillary muscles, presenting with a pan-systolic murmur and acute heart failure
• HF
• Arrhythmia
‣ More common with an Inferior MI as the artery supplies the SA
• 2nd, 3rd degree heart block
• Acute pericarditis
• Dressler’s Syndrome
‣ Pericarditis 2-3 wks post-MI, presenting with pleuritic chest pain and a fever
‣ Treated with high-dose NSAIDs