Cardiac Pathology

Question 1

Where does Atherosclerosis commonly occur?

Answer 1

Occurs throughout the vascular tree at Regions of blood vessels where you get turbulent flow, particularly at bifurcation

=all sorts of problems:
MI (coronary artistes), Ulcers in lower limb, Ischaemic limb - can lead to Amputation

Question 2

What can Atherosclerosis lead to?

Answer 2

> Coronary Artery disease > Ischaemia > Plaque rupture + Thrombosis > MI > Loss of contractility > Dilatation and ‘remodelling’ > HF

Remodelling: Helps Myocardium survive!
an adaptive response, where you have changes in size, shape, structure and function of the heart.

Question 3

Process of Atherosclerosis.

Answer 3

> start to develop ‘fatty streaks’ in your arteries from an early age.

> This build up of cholesterol + other substances eventually lead to an atherosclerotic plaque.

> the plaque itself will have a lipid cool (grows a fibrous cap) - disease of inflammatory process

> you have lots of inflammatory cells (macrophages) that invades the plaque.

If the fibrous cap ruptures, that can lead to platelet activation and Thrombosis.

Question 4

Describe the inflammatory process

Answer 4

Your changes in the endothelial layer will increase the expression of molecules which allow Monocyte Macrophage Adhesions to the Endothelium.
Then, they’ll migrate through into the Intima layer of the blood vessel in response to pro-inflammatory cytokines (perhaps)
Eventually become foam cells.

The smooth muscle cells from the Medial layer can become activated by the inflammation - differentiation process.
Migrate out into underneath the Endothelial layer -

Question 5

Cardiac Myocyte-Fibroblast interaction

Answer 5

In healthy Myocardium, fibroblasts interdigitates bw the layers of cardiac myocytes.
Role: Homeostatic

In a MI, they are Terminally differentiated cells. The inflammation occurs in response to myocyte death, so get activation of fibroblasts which proliferates and migrated into the infarct. They completely repopulate the infarct. They produce collogen which forms a scar (mature MI).

The ventricle is also dilated … bc scar starting to stretch… preload..