Acute Coronary Syndrome

Question 1

what is the definition of acute coronary syndrome?

Answer 1

Umbrella term including:

• ST elevation myocardial infarction
• Non-ST elevation myocardial infarction
• Unstable angina

Question 2

what is the epidemiology of acute coronary syndrome?

Answer 2

22.6 per 10000 per annum

Question 3

what are the risk factors for acute coronary syndrome?

Answer 3

• Age
• Male
• Family history of Ischaemic Heart Disease (IHD) - MI in first degree relative below 55
• Smoking
• Hypertension, diabetes mellitus, hyperlipidaemia
• Obesity & sedentary lifestyle

Question 4

what is the pathophysiology of acute coronary syndrome?

Answer 4

• Fatty streak → Fibrotic plaque → Atherosclerotic plaque → Plaque rupture/ fissure and thrombosis → MI or Ischaemic stroke or Critical leg ischaemia or Sudden CVS death
• In unstable angina the plaque has a necrotic centre and ulcerated cap and the thrombus results in PARTIAL OCCLUSION
• In myocardial infarction the plaque also has a necrotic centre but the thrombus results in TOTAL OCCLUSION

Question 5

what are the key presentations of acute coronary syndrome?

Answer 5

unstable angina - chest pain, new onset at rest with crescendo pattern
MI - chest pain, breathing difficulties

Question 6

what are the signs of acute coronary syndrome?

Answer 6

high pulse and reduced blood pressure

Question 7

what are the symptoms of acute coronary syndrome?

Answer 7

• Recent destabilisation of pre-existing angina with moderate or severe limitations of daily activities
• New onset angina
• Acute central chest pain, lasting more than 20 minutes, associated with:
  • Sweating
  • Nausea and vomiting
  • Dyspnoea
  • Fatigue
  • Shortness of breath
  • Palpitations
• May present without chest pain (silent infarct) e.g. in elderly or diabetics
• Distress and anxiety
• Pallor

Question 8

what are the first line investigations for acute coronary syndrome?

Answer 8

ECG - can be normal, or ST depression with t-wave inversion (NSTEMI), or ST elevation, tall t-waves, LBBB, pathological Q waves after MI (STEMI)

Question 9

what are the gold standard investigations for acute coronary syndrome?

Answer 9

• troponin I and T levels
• CK-MB levels
• Myoglobin levels
• Chest X-ray

Question 10

what are the differential diagnoses for acute coronary syndrome?

Answer 10

• Angina
• Pericarditis
• Myocarditis
• Aortic dissection
• Pulmonary embolism
• Oesophageal reflux/spasm

Question 11

how is acute coronary syndrome managed?

Answer 11

• pain relief e.g. GTN spray
• Oxygen
• Antiplatelets e.g. aspirin
• beta blockers
• statins
• ace inhibitors
• coronary revascularisation
• risk factor modifications

Question 12

what are the complications of acute coronary syndrome?

Answer 12

Disturbance of rate, rhythm and conduction
Cardiac rupture
Heart failure
Pericarditis
Ventricular septal defect
Ventricular aneurysm
Ruptured papillary muscles

Question 13

what is the prognosis of acute coronary syndrome?

Answer 13

High incidence of recurrence, 5-10% re-infarct