Acute Coronary Syndromes

Question 1

Describe the site, radiation, character, duration, exacerbating and relieving factors of ischaemic chest pain.

Answer 1

Central
Radiates to inner left arm, neck, abdomen
Crushing, band like, heavy
Remits in several mins with rest (if effort related)
Exercise, effort, stress, tachycardia
Rest, sublingual nitrate

Question 2

What is the difference between stable and unstable angina?

Answer 2

Stable - pain on exercise

Unstable - pain at rest/freq episodes of angina with less exertion

Question 3

What are the differential diagnosis of chest pain? i.e what can you confuse chest pain with?

Answer 3

MSK pain/Costochondritis
Reflux oesphagitis/GORD
Gastritis
Pericarditis
Mediastinitis

Question 4

What are the differences between unstable angina and NSTEMI?

Answer 4

Unstable angina: Pain at rest/minimal exertion, Sudden worsening of intensity or freq of episodes
NSTEMI: Evidence of myocardial damage without ST changes, may have non-specific ECG changes, history similar to UA or STEMI

Question 5

What are the complications of acute coronary syndrome? (ACS)

Answer 5

Hypotension
Cardiogenic shock
Acute Kidney Injury
Right ventricular infarction
Tachyarrhythmias
Bradyarrhythmias
Conduction defects
Papillary muscle rupture
Pericarditis
Ventricular aneurysm
Cardiac rupture
Recurrent ischaemia
Mural thrombosis
Post MI (Dressler’s) syndrome

Question 6

How can you distinguish between NSTEMI and Unstable angina? (Hint: investigation)

Answer 6

Blood test for troponin
Rise/fall - NSTEMI
Normal - Unstable angina

Question 7

How can you distinguish between unstable angina, STEMI and NSETMI based on thrombus, ECG, and cardiac enzymes?

Answer 7

Unable angina: non-occlusion thrombus, non-specific ECG, normal enzymes
NSTEMI: Thrombus enough to cause tissue damage and mild necrosis, ST dep +/- T wave inversion, inc troponin (by 6 hrs)
STEMI - complete occlusion, ST elevation, inc troponin (6 hrs), more severe symptoms

Question 8

If a patient has raised troponin levels but no ischaemic pain, are they experiencing an MI?

Answer 8

No - raised troponin levels can be due to renal failure as well

Question 9

What are the phases of myocardial infarction?

Answer 9

Ischaemic phase (lasts several minutes):
anaerobic metabolism
Infarction phase:
can't keep up with metabolic needs
irreversible damage
cell death

Question 10

How can an ECG change depending on ischaemia, injury and infarct/scar?

Answer 10

Ischemia: 
Inverted T waves
ST segment depression 
Injury:  
ST segment elevation 
Infarct/Scar:  
Pathological Q wave formation

Question 11

What is the primary or secondary prevention of ischaemic heart disease?

Answer 11

Statins, β blockade, ACE inhibitors, Aspirin, Clopidogrel, exercise, diet, smoking cessation.