cardiac pathology 2 Flashcards
what is cardiac temponade?
when fluid accumulates inside the pericardial sac and compresses the heart. it can no longer beat properly.
pericardial conditions. what is the pericardium? lined my? if any fluid accumulates there then it compresses the heart and causes?
pericardium is a sac that encloses the heart and roots of the great vessels. it is a thin, inelastic sac with internal serous membrane. lined my mesothelial cells. when fluid ccumulates it causes a temponade.
give some examples of non-inflammatory pericardial conditions? serous fluid called? blood called? what leads to these conditions?
- hydropericardium. serous exudate. due to increased hydrostatic pressure. eg. hypoproteiaemia. may be due to fluid not being cleared due to obstructive drainage.
- haemopericardium - blood. due to rupture of large vessels, puncture wounds, ruptured right haemangiosarcoma.
- idiopathic pericardial haemorrhagic effusion.
what is inflammation of the pericardial sac called? what would you see? what could causes it? commonly called? cattle?
pericarditis. you would see exudate - supprative/purulent, serous, cattarhal/mucous, fibrinous.
- haematogenous - septicaemia
- extension of infections from other tissues
- traumatic reticulitis (cattle) - ‘bread and butted pericarditis’ firbin adheres to pericardium and epicardium and causes adhesions which are yellow. much pus etc.
what are the sequelae of pericarditis? (4)
- resolution - never a clinical problem
- adhesion - organised fibrin and results in fibrosis
- constriction/atrophy - gradual temponade and cardiac atrophy
- myocarditis - trauma into the muscle also eg. traumatic reticultis.
what can the heart cells do to compensate for problems?
it cannot undergoe hyperplasia or regenerate. it may only hypertrophy!!! - concentric or eccentric.
explain hypertrophy and dilation? how would you assess these problems?
hypertrophy may be due to physical exercise or it may be pathological (stenosis or renal disease)
dilation - eccentric hypertrophy, dissease is too rapid to allow cardiac compensation. best assessed by weighing the heart and measuring the wall ratio/fibres.
give some examples of metabolic distubrbences in the heart?
6
a) hydropic degeneration - intracellular fluid. pumps inhibited due to low atp and so na and water move into the cells. they then swell up!!
b) fatty change/degeneration - fat accumulates in the cells may be due to low atp again as lipid metabolism requires atp!
c) fatty infiltration - replacement of mm bodies with fat cells - congenital.
d) hyaline degenrations - white muscle disease. vit E selenium. acute left heart failure. green/yellow streaks in the muscle.
e) calcification - mineralistaion, excess vitamin D. deposits calcium in the myocariocytes.
f) visceral gout - reptile/bird. uric acid - plus calcium = urate - tis can precipitate.
explain myocardial infarction?uncommon as dont get atheroschlerosis really. caused by? usually a result of?
caused by cholestrol. or by embolisms!! in coronary vessels.
myocarditis? what is it? usually follows? 3 types?
inflammation of the myocardium.
follows generalised infections.
acute (supprative) - septic embolism being released eg. tail bite, joint ill.
acute - non-supprative. no neutrophils but results from endocardium/pericardium.
chronic - cardiomyocytes lost. replaced by fibrous tissue. granulomas (marcophages!!)
parasitic lesions? eg? (2) main example in cattle?
cystocircus - taenia. heart, tongue, muscles of the jaw and diaphragm. 0.5-1cm.
toxoplasmosis - protozoa in cats and dogs.
cariomyopathy? - congenital or nutritional? give some examples? symptoms of mulberry heart disease?
malignant hyperthermia??
disease of the heart itself.
eg. mulberry heart disease. - lack of vit e or selenium. low in diet - lead t vascular problems and necrosis, haemorrhage, acute cardiac failure, pulmonary oedema, hepatic congestion and softening of the brain.
malignant hyperthermia - pigs. genetic. back mm necrosis. piont mutation. triggered by stress. /halothane anaesthesia. necorsis of cardia mm.
feline hyperthyroidism? - uni or bilateral. common in? causes?clinical signs? causes?
common in older cats. enlarged thyroids. adenomas. hyperactive and agressive, tachycardic, thin but have an appetite/ more thyrodi hormones - calcium?!
idiopathic cardiomyopathies?? what are they? eg? taurine? monesin? HCM - mutation in what?
unknown aetiology. change inthe heart itself. eg, dilated cardiomyopathy - (DCM) - cat horse dog. taurine deficient cats. monesin difficeint horeses. heart is enlarged. soup cowl affect. pale nd flabby. hypettrophic cardiomyopathy (HCM) - common in cats. mutations in sarcomere gene. interstitial fibrosis. frequent atheroschlerosis. cardiomegaly thickened septum.
what is a saddle thrombus and what may cause it?
it is a thrombus at the aorto-illiac junction. thromboembolism. causes posterior paresis onf hind legs. (may be caused by HCM)
