Cardiovascular pathology 2 Flashcards
Describe the appearance of normal pericardial fluid.
What is the normal volume in horses and dogs/cats?
- Clear, viscous fluid
- Horse/cow 100 ml
- Dog/cat: 10 ml
Describe a hydropericardium
Accumulation of clear to light yellow, watery, serous fluid (transudate: specific gravity < 1.015) in the pericardial sac
In which disease is a hydropericardium associated with vascular injury?
Mulberry heart disease in pigs
- a few fibrin strands are present, and the fluid could clot following exposure to air (exudate: specific gravity >1.015).
Describe the gross appearance of a hydropericardium in acute and chronic cases
Acute - pericardial surfaces are smooth and glistening
Chronic - pericardial surfaces are opaque with mild fibrous thickening due to villous proliferation of fibrous tissue
A hydropericardium is associated with diseases that have…?
Generalised oedema
Hydropericardium: Associated with those diseases that have generalized oedema - give examples
- Increased vascular permeability: viruses, bacteria, type III hypersensitivity, toxins
- Increased intravascular hydrostatic pressure: pulmonary hypertension, iatrogenic fluid overload
- Decreased intravascular osmotic pressure: decreased albumin production, protein loss
- Decreased lymphatic drainage: inflammation, obstruction
What is a cardiac tamponade?
Compression caused by fluid surrounding the heart which impairs cardiac filling and venous return to the heart
What is a haemorrhagic pericardial effusion?
Deposition of small amounts of blood, chronically - unknown aeitiology
What is a haemopericardium?
Accumulation of large amounts of blood in the pericardium
What are the consequences of a haemopericardium?
Cardiac tamponade, leading to compression and interfering with cardiac filling and emptying
What are 3 possible causes of a haemopericardium?
- Atrial rupture due to a haemangiosarcoma of the right atrium in dogs
- Rupture of the intrapericardial aorta in horses
- Complications with intracardiac injections
What is the name given to a pericardial sac filled with air, how might this occur?
Pneumopericardium
- perforations in the oesophagus/stomach pass through the mediastinum near the pericardium
How does a chylopericardium occur?
Rupture of the thoracic duct which releases chyle - often white and gelatinous
Why would serous atrophy of epicardial adipose tissue occur?
Anorexia, starvation, cachexia, as fat is catabolised to maintain energy balance
- cases of emaciation
How does atrophy of epicardial adipose tissue appear grossly?
Transformation of the white or yellow epicardial fat deposits e.g. coronary groove, into grey gelatinous material
How does atrophy of epicardial adipose tissue appear microscopically?
Lipocytes are atrophic and oedema fluid is present in the interstitial tissue
Peri- / Epicarditis is?
Inflammation of peri/ epicardium
What are the portals of entry for inflammatory processes to get to the heart?
- Foreign body penetration: From reticulum (cattle)
- Local extension of severe inflammatory processes from adjacent structures (thoracic cavity / lungs / oesophagus)
- Haematogenous spread of viruses / bacteria
Describe the different types of exudate
- Serous = watery, low in protein and inflammatory cells
- Fibrinous = acute
- Purulent = dominated by neutrophils
- Sero-fibrinous
- Fibrino–purulent
- Proliferative fibrosing = chronic inflammation
- Granulomatous = chronic, macrophage dominated
Which of the following is acute and which is chronic:
- Fibrous
- Fibrinous
- Fibrinous = acute
- Fibrous = chronic
How is the specific gravity of transudate and exudate different?
Transudate SG less than 1.015
- metabolic disorders
Exudate SG more than 1.015
- inflammatory
How does fibrinous pericarditis appear grossly?
- Pericardial surfaces are covered by variable amounts of yellow fibrin deposits, adherence between the parietal and visceral layers.
- When the pericardial sac is opened upon necropsy, these attachments are torn away
How does fibrinous pericarditis appear microscopically?
An eosinophilic layer of fibrin admixed with few neutrophils lies over a congested pericardium.