cardiovascular pathology labpeople.upei.ca/smartinson/cardiovascular_lab_1-17.pdfsignalment: •10...
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Cardiovascular Pathology Lab
Shannon Martinson, 2017 http://people.upei.ca/smartinson/
Signalment: • 10 year old MC DSH Cat History • Heart murmur detected on PE – recommended cardiac US • Blood work was done to check for hyperthyroidism - T4 levels were normal • Sudden right facial paralysis and loss of sensation of the right side of the face • Cat was euthanized
Case 1
Case 1
“Normal” cat heart for comparison
• The heart is markedly enlarged with thickening of LV free wall, the IVS, and the RV wall.
• The LV chamber in particular is reduced in size
• The atria are dilated – especially the LA which contains a large brown and tan thrombus that occludes the lumen
Description
Case 1
• Left ventricular hypertrophy, concentric, marked
• Right ventricular hypertrophy, mild to moderate
• Left atrial thrombus, occlusive
Morph Diagnosis
Usually pressure overload: • Subaortic stenosis • Systemic hypertension • Idiopathic / genetic
• Hypertrophic cardiomyopathy • Hyperthyroidism
What are possible causes for the changes in the left ventricle?
Case 1 What disease process do you think this represents?
• Hypertrophic cardiomyopathy
Why do cats with this disease develop atrial thrombosis?
• LA dilation alters laminar blood flow – predisposes to thrombosis
What is another common site for thrombosis in cats with this disease and what clinical signs might be seen as a result?
• Caudal abdominal aorta • Hind end pain /paresis • Cold extremities (hind legs) • Lack of femoral pulses
Possible embolism to the brain (stroke) from the aortic thrombus
Cause of facial paralysis:
Case 2
Signalment: • 1.5 year old intact F
Newfoundland Dog Clinical History: • Murmur detected at a young
age • Recurrent fever and previous
bouts of joint pain • Mild elevation in BUN and
Creatinine • Became anorexic and was
euthanized • Fluid in the chest and red,
heavy lungs seen at necropsy
Case 2
• There is LV hypertrophy and LA dilation
• A band of fibrous connective tissue encircles and narrows the LV outflow tract beneath the aortic valve
• The aorta is dilated above the valve
• The aortic valve is roughened and focally ruptured with a necrotic tract dissecting through to the right atrium
• The chordae and leaflets of the mitral valve are short and thick and attach from the papillary muscle to the ventricular free wall in the area of stenosis
Description
Case 2
• Subaortic stenosis, severe with poststenotic dilation
• Left ventricular hypertrophy, moderate to marked
• Valvular endocarditis, rupture, and tract formation
• Mitral valve dysplasia
Morphologic Diagnosis
Case 2
• Subaortic stenosis→ narrowing of the orifice causes pressure overload of the LV → LV concentric hypertrophy → Left heart failure → Pulmonary edema and congestion
• Increased turbulence above the valve can lead to dilation of the aorta
• The necrotic tract may have occurred as a result of high pressure and weakening of the wall at this site
Describe the hemodynamic alterations resulting from the primary lesion and relate them back to the other findings?
Case 2
• While subtle, there is endocarditis • Malformed valves are predisposed to the
development of endocarditis • The source of bacteria is often
undetermined → presumed bacteremia • Fever may occur during periods of
bacteremia or showering → anorexia • Small thromboemboli, which may be septic,
can be released causing ischemia/infection in the organs • Renal infarcts in this case may have
caused ↑urea and creatinine • Possible ischemic injury in the limbs or
septic showering of the joints may cause lameness
Can you relate the lesions back to the clinical findings / history?
Case 3
Signalment: • Aged male mixed breed dog Clinical History: • 10 day history of lethargy • Using imaging, fluid was detected in the abdomen and thorax: thoraco- and abdomino-
centesis → transudate • A 3rd degree heart block was detected (ECG) – the owners opted for euthanasia
Case 3
• A large (~8 x 4 x 5 cm) irregular solid tan and black mass infiltrates the RA obliterating the lumen and extending into the RV and IVS. The mass encompassed the aorta at the heart base.
• Both ventricles are dilated
• Multiple small (<0.5 cm) red nodular masses are present randomly within the lung.
Description
Histology!
• Hemangiosarcoma • Rhabdomyosarcoma • Chemodectoma
• Aortic body tumour • Carotid body tumour
• Ectopic thyroid carcinoma • Lymphoma
Case 3
• Malignant Neoplasia
What time of disease process is this?
What are some differentials for this lesion?
How would you reach a final diagnosis ?
Case 3
• Hemangiosarcoma, right atrium and lung
Morph Diagnosis
Case 3
Can you relate this lesion back to the clinical signs and other postmortem findings?
• RA mass could have prevented conduction of electrical activity via the AV node to the ventricles → 3rd degree heart block
• The presence of this mass resulted in congestive RHF (impedance of venous flow from the vena cava)→ ascites and hydrothorax
• Arrhythmia and CHF → lethargy • Metastasis to the lung from the primary mass
• Hemangiosarcoma, right atrium and lung
Morph Diagnosis
http://img.tfd.com/MosbyMD/conduction-system-of-the-heart.jpg
Case 3 What is a more common
outcome for these tumours?
• RA rupture → hemopericardium → cardiac tamponade
PBVD, Saunders, 2017
Case 4
Signalment: • 31 day old ram lamb. Clinical History: • Lamb was sick for 10 days and seemed to respond briefly to antibiotic treatment • Became sick again a week later with no response to antibiotics. • The lamb is now in poor body condition – the owner opted to euthanize
Case 4
Case 4
• The pericardial sac is markedly dilated (~ 15 cm diameter) and thickened by dense fibrous connective tissue with a thick covering layer of slightly friable tan shaggy material
• Similar changes are present in the epicardium
• Both the LV and RV are hyertrophied
• Fibrous adhesions span between the pericardium and pleura and there is mild CV consolidation of the lung
Description
• Organizing fibrinous pericarditis, diffuse, chronic, severe
• Biventricular hypertrophy
• Bronchopneumonia and fibrous adhesions
Morph Diagnosis
Case 4 Possible etiology?
• Bacterial infection (sepsis) • Trueperella pyogenes • Pasteurella multocida • Staphylococcus aureus • E coli
What would the most likely underlying disease process be if this was a cow?
• Traumatic reticuloperitonitis (rare in lambs)
Why is there LV and RV hypertrophy?
• Fibrosis of the epicardium and adhesion to the pericardial sac can limit diastolic expansion and cardiac output (= constrictive pericarditis)
Submit a swab for bacteriology • Antibiotic treatment may
hamper microbial growth
Case 5
Signalment: • 21 year old horse Clinical History: • Donated to AVC • Poor dentition and weight loss • Recurrent bouts of colic
Case 5
• The cranial mesenteric artery has a markedly thickened and firm (fibrotic) wall
• The lumen varies in caliber with areas of dilation and narrowing
• The intima is roughed and corrugated with brown to orange discolouration
Description
• Arteritis, proliferative, segmental, chronic, severe, with dilation (aneurysm) and fibrosis
Morph Diagnosis
• Strongylus vulgaris (L4) migration
Etiology
Case 5
• The cranial mesenteric artery has a markedly thickened and firm (fibrotic) wall
• The lumen varies in caliber with areas of dilation and narrowing
• The intima is roughed and corrugated with brown to orange discolouration
Description
• Arteritis, proliferative, segmental, chronic, severe, with dilation (aneurysm) and fibrosis
Morph Diagnosis
• Strongylus vulgaris (L4) migration
Etiology
Case 5
Can you relate this lesion to that seen in the small intestine?
• Arteritis and the resulting endothelial damage promote the formation of a thrombus at the affected site (also altered blood flow in an aneurysm) → pieces can break off as thromboemboli which lodge downstream → in this case an embolus has lodged in a mesenteric vessel
How might this result in colic?
• Thrombosis can result in infarction of the intestine (collateral circulation makes this less likely)
Case 6
Signalment: • 7 week old Holstein bull calf Clinical History : • Calf was ill-thrift, lethargic and had bluish mucous membranes • Found dead one morning
Case 6
Case 6
Case 6
• The heart is enlarged and somewhat globose in shape
• A thick muscular band narrows the right ventricular outflow tract
• The leaflets of the pulmonic valve are white-tan, thick and rugous with partial fusion of the leaflets leaving a central irregular perforation measuring ~ 0.75 cm
• There is moderate to marked RV hypertrophy and the LV ventricle appears dilated
• A 3 cm diameter opening is present high within the IVS and the aorta overrides this opening
• The ductus arteriosis is patent with a 1 cm diameter lumen
• The foramen ovale is covered by a perforated valve (probe patent)
Description
Case 6
• Pulmonic Stenosis
• Ventricular septal defect
• Right and left ventricular hypertrophy
• Over-riding aorta
• Patent ductus arteriosis
• Patent foramen ovale (~ASD)
Morphologic Diagnoses
Case 6 Which of the identified changes would be found in tetralogy of Fallot?
• Pulmonic stenosis • Ventricular septal defect • Over-riding aorta • Right ventricular hypertrophy
Which of these are congenital and which are acquired?
Congenital
Acquired
• Pulmonic stenosis • Ventricular septal defect • Over-riding aorta • Right ventricular hypertrophy
• Patent foramen ovale OR • Patent Ductus Arteriosis
Pentology of Fallot
Pulmonic stenosis
RV pressure overload
R to L shunt through VSD
Cyanosis
RV hypertrophy Right heart
failure
Shunt through the ASD and
PDA?
Case 6 What are the hemodynamic alterations in this case?
PDA and ASD are not though to contribute much to clinical disease when present along with tetralogy