Cardiovascular Pathology 3 Flashcards
What do the lesions look like histologically and grossly?
composed of fibrin matrix, necrotic debris, neutrophils and bacteria. They are located on the outflow surface of the valves
Can be granulation tissue with embedded bacterial colonies (chronic)
What is endocarditis and what causes it?
inflammation of the endocardium.
valvular trauma due to blood turbulence, valve tissue ageing, avascularity of valves, exposure of valve to pathogens.
What are the two possible sequelae of endocarditis?
Rupture of friable vegetations with resulting septic embolism= R side lesions- pulm embolism and abscessation, L side lesions- myocardial + peripheral infarction and infection.
Valvular stenosis/incompetence= narrowing of the valve orifice or inadequate seal against back flow of blood.
What are 2 examples of degenerative valvular disease?
myxomatous valvular disease/endocarditis.
chronic valvulopathy
Which degenerative valvular disease is seen in horses and what does it look like?
Chronic valvulopathy- sparse chronic inflammation with fibrous scarring, most significant lesions affect the main mitral and aortic valve cusps
What can be seen in the 3 layers of the cusp?
1) sparse cellular infiltrations (lymphocytes, macrophages and fibroblasts) in the superficial layer.
2) variable villous or papillary eruptions of the outflow endothelium
3) the deeper layers often show irregular whorls or meshes of collagen fibres which can be more organised= cuspal nodulation.
What changes are seen in endocardiosis and how are the lesions graded?
Changes seen in the AV valves- Mitral.
Very common in older dogs.
They are graded from (whitney 1-4), from smooth, white, discrete nodules through to coalescent nodules to plaque-like thickenings with cuspal distortion and chordal rupture.= leakage.
What is necrotising endocarditis?
isolated foci of necrosis on the LA endocardium above the LAV valve ring in dogs with uraemia.
What is endocardial calcification?
deposits of Ca and fibrous tissue which can spread to the myocardium. Mineral imbalance e.g. high dietary Ca, soil-rich K, low in Mg/P
Where are the haematocysts and lymph cysts found?
In the AV valve cusps at their attachments to the chordae or valve ring.
What is melanosis?
Melanin deposition on heart valves and mural endocardium- Scottish Blackface and black breeds of cattle.
What are Jet lesions?
Fibrous thickenings of the endocardium adjacent to a competent valve.
What happens if jet lesions are present?
Abnormal jets of blood pass through a stenotic semilunar valve and strike the vessel endothelium
What are the three types of primary cardiac neoplasia?
Haemoangiosarcoma
Heart-base tumours
thyomas, ectopic thyroid tumours.
Where does a haemangiosarcoma arise?
In the right atrium/auricle and the base of the RV.
Liver, spleen and skin.
