3 – Pericardium and Endocardium Flashcards
Serous atrophy of fat
- *gelatinous appearance
- Epicardial fat
- Bone-marrow
- Kidney
When does serous atrophy of fat occur?
- When individual has a NEGATIVE energy balance
- Starvation
- Chronic inflammation (Ex. Johnes)
- Severe GI problems
Pericardial hemorrhages common post-mortem finding in animals that suffered
- Hypoxia
- Sepsis or septicemia
- Toxemia
- DIC
- Coagulopathies
- Electrocution
- *terminal finding in large animals
Classification of hemorrhages: according to size
- Petechial
- Ecchymotic
- Paint brush
Pericardial effusions
- Accumulation of fluid in the pericardial sac
- Transudate, blood, exudate
Distention of the pericardial sac: notably enlarge on physical damage to accommodate
- Excess fluid in hydropericardium
- Non-fatal progressive pericardial hemorrhage in hemopericardium
- Exudate in pericarditis
- Enlarged heart in cardiac hypertrophy and cardiomyopathy
Transudate
- Clear fluid
- Low cellularity
- Low protein
Exudate
- Turbid
- High cellularity
- PMNs (polymultinuclear neutrophils)
- High protein
Hydropericardium
- Transudate pericardial effusion
- Pericardial surfaces remain SMOOTH and GLISTENING
Hydropericardium pathogenesis
- Hydrostatic
- Hypoproteinemia
- Altered vascular permeability (ex. mulberry heart)
- *can be due to salt (NaCl) toxicity in chickens
Hydrostatic pathogenesis for hydropericardium
- R heart failure
- Pulmonary hypertension
Hypoproteinemia pathogenesis for hydropericardium
- Emaciation
- Protein losing enteropathy/nephropathy
Hemopericardium
- Blood pericardial effusion
- Predominantly RBCs
- High protein
- Caution: blood-tinged fluid occurs normally as a post-mortem finding
Hemopericardium can be caused by
- Atrial or aortic rupture
- Hemangiosarcoma
- Cardiac trauma/puncture
- *acute hemorrhage can cause CARDIAC TAMPONADE->sudden DEATH
Hemangiosarcoma in dog causing hemopericardium
- Dark b/c neoplastic cells form blood-filled vascular channels
Pericarditis
- Exudate pericardial effusion
According to the exudate in pericarditis: classification
- Fibrinous (most common)
- Suppurative (purulent)
- Fibrinohemorrhagic
- Granulomatous
Fibrinous pericarditis
- APPEARANCE: ‘bread and butter’, ‘cor villosum’
- Most commonly a result of bacterial infection
- Can be due to extension of a local inflammatory process
Polyserositis (Glasser’s disease)
- Due to GLAESSERELLA PARASUIS
- Fibrin and fluid in pericardial sac
- Fibrinopurulent exudate in joints
- (streptococcus suis type 2 can cause similar lesions in pigs)
Black leg (clostridial myositis)
- Fibrinous pericarditis commonly seen
o Fibrin strands in pericardial sac - Black discolouration of leg muscle
Traumatic reticulopericarditis
- When ruminant eats wire or nails and it pokes forward into the pericardium
- Dilated and thickened pericardial sac with fibrosis
- Sac is filled with exudate
- Epicardial surface is covered by exudate
Chronic pericarditis
- Brisket edema due to heart failure (compressive)
- Distended pericardial sac
- Sac filled with fibrin and blood
- Organized fibrin on epicardium
Chronic constrictive pericarditis
- Heart is encased in a dense fibrous or fibrocalcific scar
- May obliterate pericardial space
- *in extreme cases=resembles a plaster mold (‘concretio cordis’)
Examples of endocardial diseases
- Endocardial fibrosis
- Endocardial mineralization
- Valvular cysts
- Endocarditis
- Myxomatous degeneration
Acquired (secondary) fibrosis
- Focal or generalized
What is the most common cause of focal acquired fibrosis?
- Abnormal blood turbulences in atria or ventricles caused by ‘jet lesions’
“jet lesions”
- Occur when mechanical injury caused by turbulence damage to the endocardium
- Commonly seen in valvular insufficiencies (see them on the atrial endocardium)
What is the most common cause of diffuse acquired fibrosis?
- Sub-endocardial fibrosis secondary to prolonged cardiac dilation
Primary endocardial fibroelastosis
- Occurs as hereditary disease in humans and Burmese cats (no underlying cardiac disease)
- Pathogenesis is uncertain
Gross lesions and microscopic lesions of endocardial fibrosis and fibroelastosis
- Endocardium appears thickened=due to abnormal deposition of collage and elastic fibers
o smooth or corrugated surface
Clinical relevance of endocardial fibrosis and fibroelastosis
- Severe generalized fibrosis can impair ventricular filling during diastole and reduced SV leading to congestive heart failure
Subendocardial fibrosis
- Increased collagen deposition
o secondary to prolonged blood turbulence caused by a congenital heart defect - Grossly: diffusely white, thickened endocardium
Endocardial mineralization
- Abnormal deposition of calcium or mineral in the endocardium
Types of endocardial mineralization
- Metastatic
- Dystrophic
Metastatic endocardial mineralization
- High levels of circulating Ca2+ in hypercalcemic states
Dystrophic endocardial mineralization
- Secondary calcification in INJURED endocardium
What are the most common causes of endocardial mineralization in domestic animals?
- Hypervitaminosis D
- Chronic granulomatous diseases
- Uremia (uremic endocarditis)
Hypervitaminosis D (endocardial mineralization)
- When give excess vitamin D
- Ex. ingest Vitamin D analogs=present in some rodenticides or toxic plants
Toxic plant examples for VItamin D analogs
- Solanum malacoxylon
- Cestrum diurnum
- Trisetum flavescens
Chronic granulomatous diseases (endocardial mineralization)
- Ex. bovines with paraTB or TB
o Endocardial and arterial mineralization
Valvular cysts
- Particularly common in calves
- ‘incidental finding’
- Can regress or disappear
- No clinical significance
Cysts are classified as
- Lymphocyst
- Hematocyst
Lymphocyst
- Content is clear fluid
Hematocyst
- Content is blood
Myxomatous valvular degeneration (endocardiosis)
- Most common cardiac lesion found at necropsy in mature dogs
- Incidence increases with age
- Typically affects mitral valve
- NODULAR THICKENING of valve with a smooth, shiny surface
o May see hooding of leaflets toward the atrium (valve prolapse) - May or may not cause valvular dysfunction and clinical signs
Endocardiosis and ruptured chordae tendineae
- Rupture causes eversion of leaflet into atrium
- Test by filling ventricle with water and compressing the heart, if rupture=1 or more chordae will whip out during ‘manual systole’
Endocarditis
- Inflammation of the endocardium
- Occurs in all species
- Most frequently caused by BACTERIA (less extent by fungi and parasites)
- Classify based on location and gross appearance
Endocarditis based on location
- Valvular endocarditis (valves)
- Mural endocarditis (ventricular or atrial wall)
Endocarditis based on gross appearance
- Vegetative
- Ulcerative
Vegetative endocarditis
- Cauliflower-like mass of exudate and fibrin attached to a heart valve OR endocardium
Ulcerative endocarditis
- Endocardium is ulcerated
- Ex. dogs with uremia
What is a common sequel to endocarditis?
- Thromboembolism
o Mitral or aortic endocarditis often cause renal infarcts
o Tricuspid and pulmonic endocarditis cause pulmonary infarcts or embolic pneumonia
Vegetative valvular endocarditis
- Common in farm animals (pigs and cattle) suffering from BACTEREMIA
- Occasionally seen in dogs and cats
What are the most common bacteria isolated from endocarditis in horses?
- Streptococcus equi
- Actinobacillus equuli
What are the most common bacteria isolated from endocarditis in cattle?
- Trueperalla (Arcanobacterium) pyogenes
What are the most common bacteria isolated from endocarditis in pigs?
- Erysipelothrix rhusiopathiae
- Streptococcus suis type II
What are the most common bacteria isolated from endocarditis in dogs?
- Staphylococcus aureus
What are the most common bacteria isolated from endocarditis in cats?
- Bartonella
- Streptpococcus sp.
Vegetative mass on tricuspid valve in cow causing
- Right sided heart failure
- Hydrothorax
- ‘nutmeg liver’
Vegetative valvular endocarditis: histopathology
- Bacterial colonies
- Neutrophils and cell debris
- Connective tissue and macrophages
What is the lesion that indicates embolism?
- Multiple embolic foci (white dots surrounded by a red halo)
What can all be seen in a dog with uremia with chronic renal failure?
- Endocarditis
- Mineralization
- Fibrous tissue (scar) formation
