Lecture 28

Question 1

typical gross appearance of health pericardial sac

Answer 1

smooth and glistening (mesothelial cells) containing just enough fluid for frictionless cardiac movement

Question 2

What are the functions of the mesothelial cells lining the sac?(3)

Answer 2

if activated then capable of phagocytosis-
-can produce plasminogen activator-> fibrinolysis (protection against adhesion formation)
produce low viscosity lubricant

Question 3

Why do we have a pericardial sac(3)

Answer 3

prevent sudden dilation of heart chambers
compensation for gravity
prevent spread of infectious agent from pleural cavity to heart

Question 4

Constrictive heart disease

what can it be caused by?

Answer 4

reduced ventricular compliance (impaired diastolic filling of R heart)->R sided CHF
rapid pericardial effusion

Question 5

cardiac tamponade
caused by (3)

Answer 5

excess volume of fluid in the pericardial sac

caused by: hydropericardium, hemopericardium, pericardititis

Question 6

Hydropericardium

Answer 6

accumulation of non inflammatory fluid in the pericardial sac

Question 7

possible mechanisms for hydropericardium(4)

Answer 7

R CHF- venous drainage of capillary beds of pericardium is to the right heart
hypoalbuminemia
local venous or lymphatic obstruction
inc vascular permeability

Question 8

typical gross appearance of hydropericardium

Answer 8

fluid that is clear to cloudy-may form gel if there is inc fibrinogen
serosal membranes remain smooth and glistening

Question 9

hemopericardium

Answer 9

free blood in the pericardial sac (commonly fatal-cardiac tamponade)

Question 10

causes of hemopericardium
1 general
dog
horse
cattle

Answer 10

penetrating trauma with puncture of the heart
dog-bleeding hemangiosarcoma in right auricle
horse-idiopathic during high speed racing
cattle- hardward disease

Question 11

2 major types of pericarditis

Answer 11

fibrinous pericarditis (more common)
supprative pericarditis

Question 12

most common cause of fibrinous pericarditits

Answer 12

hematogenous localization of infectious agent (e coli)

Question 13

gross appearance of fibrinous pericarditis(3)

Answer 13

small volume of exudate
inflamed serosal membrane- hyperemic and several small hemorrhages
cor villosum-tiny villous projections

Question 14

which species is supprative pericarditis most common and why

Answer 14

cattle and traumatic reticuloperitonitis

Question 15

difference between fibrinous and supprative in terms of cardiac function

Answer 15

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

Question 16

what would serous atrophy of epicardial fat indicate

Answer 16

anorexia, cachexia, starvation

Question 17

Common cause of hemorrhage over the epicardium or parietal pericardium

Answer 17

acute infections

Question 18

gout

Answer 18

crystals are needle like, colorless and caused by excessive production or insufficient excretion of uric acid and urates

Question 19

what species is visceral gout likely to be seen in necropsy(2)

Answer 19

birds, reptiles

Question 20

typical gross appearance if endocardium in health

Answer 20

smooth and glistening due to integrity of endothelium

Question 21

What gross change may indicate presence of subendocardial fibrosis

Answer 21

becomes milky white and opaque

needs to be distinguished from fat

Question 22

Usual cause of subendocardial fibrosis

Answer 22

chronically dilate heart chambers

Question 23

What circumstances can mineral be deposited in endocardium

Answer 23

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)

Question 24

Endocardiosis

Answer 24

myxomatous degeneration of the heart valves

most common cardiovascular lesion in dogs(middle aged and older)

Question 25

Aetiopathogensis of endocardiosis

Answer 25

inherited generative disease of CT (collagen)

polygenic inheritance

Question 26

Which heart valves are affected in endocardiosis

Answer 26

mitral valve

margins of the valves are thickened (short and thick)

Question 27

Most common cause of endocarditis

Answer 27

valvular endocarditis- bacteremia

large animals and especially pigs

Question 28

where are endocarditis lesions most often located?

gross appearance

Answer 28

mitral>aortic>tricuspid>pulmonic

large, friable, rough surfaced, yellow-grey-red, vegetations largely composed of thrombus and leukocytes

Question 29

Potential consequences of valvular endocarditis

Answer 29

often fatal
valves become stenotic or insufficient->CHF
thromboembolism