Myocardial Infarction

Question 1

What anatomical structures are affected?

Answer 1

It affects
1) the left coronary artery and its branches (LAD)

2) right coronary artery - posterior descending artery

In an MI these arteries are stenosed which can cause a blood clot.

Question 2

How does this affect the heart?

Answer 2

1) ischaemia
2) heart can’t contract properly
3) abnormal electrical activity of heart cells

Question 3

What prior events cause an MI

Answer 3

More common in men and elderly 👴🏽

Family history tree 🌲

Smoking, high BP, high cholesterol, high blood sugar, diabetes, low exercise, obese

Question 4

Symptoms

Answer 4

Chest pain, can spread to arms.

Nausea/vomiting 🤢

Breathless

Pulmonary oedema - fluid in lungs

Question 5

Test results show?

Answer 5

ECG shows elevated ST segment if coronary artery is completely blocked.

High levels of troponin

Angiogram - shows an artery blocked by atheromstous stenosis and by thrombosis

Question 6

How to treat?

Answer 6

Pain relief with morphine, given with highflier oxygen.

Oral aspirin

Thrombolytic drugs

Primary percutaneous intervention(opens narrowed artery and a metal stent placed to hold artery open

Question 7

What are the key drugs used to treat an MI?

Answer 7

Aspirin - anti platelet

Clopidogrel - anti platelet

Beta blockers - lowers heart and blood pressure

Statins - hMG CoA reductase inhibiters lower cholesterol.

ACE-inhibitors - inhibit ACE, prevents angiotensin 2 being made which prevents vasoconstriction. Lowers BP