Lecture 28 Flashcards
typical gross appearance of health pericardial sac
smooth and glistening (mesothelial cells) containing just enough fluid for frictionless cardiac movement
What are the functions of the mesothelial cells lining the sac?(3)
if activated then capable of phagocytosis-
-can produce plasminogen activator-> fibrinolysis (protection against adhesion formation)
produce low viscosity lubricant
Why do we have a pericardial sac(3)
prevent sudden dilation of heart chambers
compensation for gravity
prevent spread of infectious agent from pleural cavity to heart
Constrictive heart disease
what can it be caused by?
reduced ventricular compliance (impaired diastolic filling of R heart)->R sided CHF
rapid pericardial effusion
cardiac tamponade caused by (3)
excess volume of fluid in the pericardial sac
caused by: hydropericardium, hemopericardium, pericardititis
Hydropericardium
accumulation of non inflammatory fluid in the pericardial sac
possible mechanisms for hydropericardium(4)
R CHF- venous drainage of capillary beds of pericardium is to the right heart
hypoalbuminemia
local venous or lymphatic obstruction
inc vascular permeability
typical gross appearance of hydropericardium
fluid that is clear to cloudy-may form gel if there is inc fibrinogen
serosal membranes remain smooth and glistening
hemopericardium
free blood in the pericardial sac (commonly fatal-cardiac tamponade)
causes of hemopericardium 1 general dog horse cattle
penetrating trauma with puncture of the heart
dog-bleeding hemangiosarcoma in right auricle
horse-idiopathic during high speed racing
cattle- hardward disease
2 major types of pericarditis
fibrinous pericarditis (more common) supprative pericarditis
most common cause of fibrinous pericarditits
hematogenous localization of infectious agent (e coli)
gross appearance of fibrinous pericarditis(3)
small volume of exudate
inflamed serosal membrane- hyperemic and several small hemorrhages
cor villosum-tiny villous projections
which species is supprative pericarditis most common and why
cattle and traumatic reticuloperitonitis
difference between fibrinous and supprative in terms of cardiac function
fibrinous- if persists 5-7 days->granulation tissue, but usually no compromise of cardiac function
supprative- probably never completely resolves->scar tissue->constrictive pericarditis->R CHF
what would serous atrophy of epicardial fat indicate
anorexia, cachexia, starvation
Common cause of hemorrhage over the epicardium or parietal pericardium
acute infections
gout
crystals are needle like, colorless and caused by excessive production or insufficient excretion of uric acid and urates
what species is visceral gout likely to be seen in necropsy(2)
birds, reptiles
typical gross appearance if endocardium in health
smooth and glistening due to integrity of endothelium
What gross change may indicate presence of subendocardial fibrosis
becomes milky white and opaque
needs to be distinguished from fat
Usual cause of subendocardial fibrosis
chronically dilate heart chambers
What circumstances can mineral be deposited in endocardium
dystrophic mineralization (more common)- in necrotic tissues (eg Johnes disease) metastatic mineralization- deposition in healthy tissue due to inc of Ca or phosphate (poisoning with Vit D)
Endocardiosis
myxomatous degeneration of the heart valves
most common cardiovascular lesion in dogs(middle aged and older)
Aetiopathogensis of endocardiosis
inherited generative disease of CT (collagen)
polygenic inheritance
Which heart valves are affected in endocardiosis
mitral valve
margins of the valves are thickened (short and thick)
Most common cause of endocarditis
valvular endocarditis- bacteremia
large animals and especially pigs
where are endocarditis lesions most often located?
gross appearance
mitral>aortic>tricuspid>pulmonic
large, friable, rough surfaced, yellow-grey-red, vegetations largely composed of thrombus and leukocytes
Potential consequences of valvular endocarditis
often fatal
valves become stenotic or insufficient->CHF
thromboembolism
