Histopathology 6 - Vascular and Cardiac pathology Flashcards
(46 cards)
What are the 3 stages of atheroma development?
- Raised lesion
- Soft lipid core
- White fibrous cap
Are men or women more affected by atherosclerosis?
premenopausal women protected → post-menopausal women = >risk than men
Recall the 7 steps of atheroma pathophsyiology
- endothelial injury → LDL accumulation
- monocyte adhesion to endothelium
- monocyte migration into intima → macrophages & foam cells
- platelet adhesion → factor release → smooth muscle cell recruitment
- lipid accumulation → extracellular and intracellular macrophages and smooth muscle cells
What % atheroma of a vessel lumen is considered ‘critical stenosis’?
70%
What lesions can you visualise on histology in atherosclerosis?
1. Fatty streak
Lipid filled foamy macrophages, no flow disturbance
In virtually all children <10y/o
Relationship to plaques uncertain but same sites as plaques
2. Atherosclerotic plaque
Occur in points of disturbed flow - bifurcations, curvatures
What is prinzmental angina?
Coronary artery spasm
Where do plaques commonly form in angina?
first parts of LAD or LCx; or entire length of RCA
Which parts of the cardiac muscle are affected by an infarction of the LAD?
Anterior wall of left ventricle, anterior septum and apex
Which parts of the cardiac muscle are affected by an infarction of the RCA?
Posterior wall of left ventricle, posterior septum and posterior wall of right ventricle
Which parts of the cardiac muscle are affected by an infarction of the LCx?
Lateral wall of left ventricle
What are the 4 most important complications of MI?
- Contractile dysfunction (eg cardiogenic shock)
- Arrhythmia
- Myocardial rupture
- Pericarditis
D Death
A Arrhythmia
R Rupture (papillary muscle)
T Tamponade
H Heart Failure
V Valvular disease
A Aneurysm of ventricle
D Dressler’s syndrome (pericarditis; 2nd or 3rd day)
E Embolism (i.e. bowel ischaemia)
R Recurrence
What is Dressler’s syndrome?
Pericarditis occuring weeks-months post-MI
What is the average time between MI and myocardial rupture?
4-5 days
What histological findings would be found within 6 hours of an MI?
Normal histology and normal CK-MB
What histological findings would be found 6 -24 hours following an MI?
Loss of nuclei
Homogenous cytoplasm
Necrotic cell death
What histological findings would be found 1-4 days following an MI?
Infiltration of polymorphs and macrophages
What histological findings would be found 5-10 days following an MI?
Removal of debris
What histological findings would be found 1-2 weeks following an MI?
Granulation tissue
New blood vessels
Myofibroblasts
Collagen synthesis
What histological findings would be found in the months following an MI?
Strengthening, de-cellularising scar tissue
Recall the possible complications of MI
Mnemonic = PACE MAKERED
Papillary muscle dysfunction
Arrhythmia
Ccf
Effusion (pericardial)
Mural thrombus
Aneurism (ventricular)
(K)ontractile dysfunction
Early pericarditis
Rupture of venticular wall
Elevation of ST segment
Dressler’s syndrome
What is reperfusion injury?
oxidative stress, Ca2+ overload, inflammation
- Arrhythmias common
- Biochemical abnormalities last days to weeks
- Thought to cause “stunned myocardium”: reversible cardiac failure lasting several days
What is hibernating myocardium
chronic sublethal ischaemia causes lowered metabolism in myocytes is reversed with revascularisation
What is a cause of sudden cardiac death?
lethal arrhythmia (from ischaemia-induced electrical instability)
Usually BG IHD (90%) although drugs such a cocaine may be the cause
Acute MI is usual trigger → electrical instability at sites distant from conduction system (near scars from old MIs)
What is nutmeg liver a sign of?
peripheral oedema (hepatic venous congestion)
