Flashcards in Cardiovascular Pathology 4 Deck (25):
What is arterial hypertrophy?
An increase in the elastic components of the media and intima layers- response to hypertension.
What changes are seen in arterial hypertrophy?
Local changes are seen in renal arteries and causes chronic nephritis in dogs and cats.
Hypertrophy of the intimal and medial layers in dogs with heart worm.
What is Arteriosclerosis and what diseases is it seen in?
Fibrous thickening and degeneration of the arterial wall.
Hypertrophic cardiomyopathy in cats and myxomatous mitral valve disease in small dogs.
What are sclerotic lesions characterised by?
Mucopolysaccharide accumulation in the intima, followed by fibrosis, calcification and muscle hypertrophy.
Sub-intimal layers are disrupted and there may be duplication of the internal elastic lamina- no marked inflammation, plaques and grey streak-like markings.
What is atherosclerosis?
Accumulation of cholesterol in the vessel wall- atheroma.
Rare- can be due to hypercholesterolaemia or hypothyroidism.
What is amyloidosis and where are the two types found?
It is an insoluble protein derived from Ig light chain or from SAA.
AL type is associated with Ig-secreting malignant plasma cell neoplasia.
AA type- Ideopathic familial condition
Where can amyloid deposits be found?
in renal vessels and glomeruli, splenic white pulp, spaces of Disse (sinusoids), coronary and meningeal arteries.
In the cats=renal medulla, Pancreatic islet cell amyloidosis in older cats.
What are the two types of calcification?
metastatic- hypercalcaemia. Large arteries have plaque-like lesions and can be completely encircled.
How is Johne's Disease different in terms of calcification?
Shows metastatic calcification but there is no hypercalcaemia.
What is arteritis and what are the two types called?
It is inflammation of the arterial walls.
Infectious and non-infectious
What is generalised infectious arteritis?
It is bacterial, e.g. FIP (feline corona virus), distemper.
What is localised infectious arteritis and what do the lesions look like?
Local extension of an infective focus, especially if it is suppurative or necrotising. e.g. pasturella spp, meningitis.
Lesions are petechial haemorrhages on serosal surfaces in adrenal glands and visible mucosa.
What do localised infectious arteritis lesions look like microscopically?
Lesions affect the endothelium and intima which swell and the muscle layer undergoes necrosis. Thrombosis can occur. lesions tend to be confined to the outer layers.
What is polyarteritis nodosa and what do its lesions look like?
It is a non-infectious arteritis. it affects the media of the arteries and arterioles.
fibrinoid necrosis of the media with intense neutrophil invasion.
How do the nodules form in polyarteritis nodosa?
As a result of extensive granulation reaction, with eosinophils, plasma cells and lymphocytes.
Could be due to type III hypersensitivity- Ab-Ag complexes.
How can parasites cause arteritis?
Strongylus vulgaris- larvae and adults migrate through arterial walls and cause intimal damage. Lesions are found in the ascending aorta, roots of the cr mesenteric, ileocaecal and renal arteries.
What are aneurysms?
Balloon-like dilation of the wall of an artery due to weakening and loss of elasticity, blood enters the wall to form a bulge.
Were is an aneurysm seen?
Proximal to a stenotic lesion or as a result of weakening following vascular degeneration or excessive blood flow- PDA.
e.g. verminous aneurysm
When can aortic rupture occur?
In the horse as a result of a verminous aneurysm- rupture of the root of the aorta. This can happen after a racehorse has run- the heart can cope with the extra strain but the aorta root cannot= sudden death due to haemorrhage into the pericardial sac and cardiac tamponade.
What does aortic thrombosis look like grossly?
Firm, dark, red aggregate in the posterior aorta and extending into the iliac arteries.
What is aortic thrombosis most common in and what will it result in?
male cats with hypertrophic cardiomyopathy or atrial thrombosis.
Sudden posterior paralysis with hypothermia of hind-limbs and loss of femoral pulse due to embolisation of a left atrial thrombus = "saddle thrombus"
What are the two diseases of veins?
Thrombosis, phlebitis or rupture
When can venous thrombosis occur?
In cattle with traumatic reticulitis or liver abscesses, the caudal vena cava can become thrombosed.
What is phlebitis of veins and how does it occur?
Inflammation of veins. It accompanies thrombosis, vene puncture where sterility is poor or irritants are injected e.g. farmers injecting Ca into milk vv.