L2: Introduction to Cardiovascular Medicine

Question 1

What are the functions of the cardiovascular system?

Answer 1

• To distribute oxygenated blood around the body to the viscera
  
  • To maintain homeostasis - through the distribution of heat, hormones, nutrients etc.
  • Distribute white blood cells so that they can fight infection
  • Removal of waste products
  • Respond to changing demands such as exercise and temperature
    Stop bleeding and repair damage

Question 2

What are the risk factors for coronary heart disease?

Answer 2

Risk factors for coronary heart disease:
- Dyslipidaemia - having an abnormal level of lipids in the blood
- Smoking
- Diabetes
- Hypertension
- Gender - males have a higher chance than females
- Age - as we age, out chances increase
- Family history
Other factors include:
- Diet and exercise - leading a sedentary lifestyle increase chances
- Inflammatory disease such as rheumatoid arthritis
- Heritage - those of a South Asian ethnicity have a higher chance
- Socio-economic status - those of a lower socio-economic status have a higher chance of coronary heart disease
Birth weight - a lower birth rate increases chances

Question 3

What is atherosclerosis?

Answer 3

The narrowing of the airways.

Question 4

How does atherosclerosis occur?

Answer 4

1. Endothelial damage occurs. This leads to the expression of inflammatory molecules such as ICAM and selectins. They have an interaction with neutrophils to get them to slow down and stop at the endothelium. This causes the epithelium to release of inflammatory cytokines. There is also an increased permeability to inflammatory cells, lipids
   
   2. Monocytes differentiate into macrophages. There is T-cell action. Lipids accumulate which are presented as a fatty streak seen on microscopes. Cells become lipid laden.
      Lipid-ladenalveolar macrophages, also known as pulmonary foam cells, are cells found in bronchoalveolar lavage (BAL) specimens that consist of macrophages containing deposits oflipids(fats).
      Foam cells, which are cells that are full of so much fat they adopt a fluffy white appearance, under apoptosis. The lipid pools in subendothelial space. This leads to plaque development with a fibrous collagen cap developing.
   3. The plaque then becomes complex.
   4. The Plaque can rupture. This leads to thrombogenic core exposed to blood causing the clotting cascade to be activated. Platelets are recruited and a thrombus forms. This causes Vessel occlusion which can lead to ischaemia and infarction.
      The clot can also embolise. Distal vessel occlusion can therefore have arrhythmogenic potential.

Question 5

What are the two types of angina?

Answer 5

Stable angina: is chest pain or discomfort that most often occurs with activity or emotional stress.

Unstable angina: should be treated as an emergency. It is irregular and can occur when at rest.

Question 6

How do we differentiate between stable angina and unstable angina?

Answer 6

When diagnosing angina, you look at three features:

1. Constricting discomfort in the front of the chest, or in the neck, shoulders, jaw, or arms
2. Precipitated by physical exertion
3. Relieved by rest or GTN within about 5 minutes.

A score of:
Typical angina = 3/3
Atypical angina = 2/3
Non-anginal chest pain = 1 or 0/3

Question 7

When is chest pain unlikely to be angina?

Answer 7

Chest pain is unlikely to be angina is: 
	- It is continuous or very prolonged 
	- Unrelated to activity 
	- Can be brought on by breathing in 
Is associated with symptoms such as dizziness, palpitations, tingling or difficulty swallowing.