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