L28: Diseases Pericardium and Endocardium Flashcards
Describe 3x functions of mesothelial cells
- secrete serous fluid
- When activated can phagocytose/ produce plasminogen activator to generate plasmin and rid of fibrous exudate
- Can beat irritation by sloughing, hypertrophying, hyperplasia, metaplasia
why do we have a pericardial sac?
maintain hydrostatic pressure on ventricles at diastole
prevent sudden dilation chambers
what is constrictive heart disease and which chamber is most at risk?
myocardium is restricted from filling.
Particularly RV because its a weakling
What is cardiac tamponade?
fluid accumulation in the pericardial sac
What factor is most important in regard to the severity of cardiac tamponade?
the rate of fluid accumulation, not the volume of fluid itself!
what kind f heart failure is likely to result from cardiac tamponade?
R sided congestive heart failure (RV is weak)
How might hydropericardium develop?
hypoalbuminaemia
Local venous/ lymphatic obstruction
INC vascular permeability (renal failure, endothelial cell damage)
Why is haemopericardium commonly fatal?
usually big, quick bleeds into pericardial sac, e.g. rupture of coronary vessel etc.
What are some common causes of haemopericardium?
rupture of coronary vessel Haemangiosarcoma rupture In horses, quick transitory rises in BP can cause rupture of intra-pericardial aorta, pulmonary artery Hardware Dx Trauma
What are the 2x major forms of pericarditis seen in domestics ?
Fibrinous (inflammation of parietal/ visceral pericardium, accumulation exudate) due to bacteraemia/ virus/ parasite
Suppurative (high volume exudate, immune cells release free radicals + proteases, tissue damage)
What is the most common cause of suppurative pericarditis ?
Hardware Dz
What affects cardiac function more, suppurative or fibrinous?
Suppurative
Often quicker onset, + immune cell free radicals + never completely resolves (granulation tissue/ fibrosis -> pericardial sac replaced with dense scar tissue)
What does serous atrophy of epicardial fat indicate?
Very anorexic animal –> has recently mobilised epicardial fat deposites
What is gout?
deposition of urate crystals + inflammation (e.g. due to excess protein, severe dehydration, renal nephrosis) in reptiles & birds
What PM artefacts might you find in an animal’s pericardial sac/
crystals in pericardial sac if euthanised intra-cardiac and some spilled out (barbiturates)
Pericardial membranes discoloured due to lysing of RBC
Where is the endocardium found
vascular endothelium lining the inside chambers of the heart
Diffuse/ focal milky areas of the endocardium might indicate what?
damage + healing –> subendocardial fibrosis
What is a jet lesions and where are they commonly found
Linear localised fibrosis due to trauma from jets of blood
Valve insufficiency
why might mineral be deposited in the endocardium?
dystrophic mineralisation (mineral deposits in necrotic tissues)
Metastatic mineralisation (inc blood conc Ca, PO3-)
What is endocardiosis?
Myxomatous (degeneration CT) degeneration of heart valves :(
V common in dogs
Provide some aetiopathogenses for endocardiosis in dogs
Inherited (cavalier, dachshunds)
Heart valve disease
Inherited CT disorder
Which heart valve is most commonly affected with endocardiosis
mitral
what gross lesions suggest endocardiosis
thickened valve leaflets
+ fibroelastic tissue
nodules
What are potential consequences of mitral/ tricuspid endocardiosis?
Generally the heart compensates …
valve insufficiency > regurgitation > volume overload on atrium @ systole > volume overload ventricle @ diastole > eccentric hypertrophy
what is endocarditis ?
inflammation endocardium
what is the most common cause of endocarditis
inflammation
thrombosis
bacterial colonies
What species are most commonly seen with endocarditis
horses & pigs
Where are most endocarditis lesions located?
LHS
at Valve leaflets towards blood flow
Horses –> aortic valve
What are potential consequences of valvular endocarditis?
often fatal because lead to stenotic/ insufficient valves and eventually lead to heart failure
