Cardiovascular Pathology Lab. Shannon Martinson,

Transcription

1 Cardiovascular Pathology Lab Shannon Martinson,

2 Case 1 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

3 Case 1 Description 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

4 Case 1 Morph Diagnosis Left ventricular hypertrophy, concentric, marked Right ventricular hypertrophy, mild to moderate Left atrial thrombus, occlusive What are possible causes for the changes in the left ventricle? Usually pressure overload: Subaortic stenosis Systemic hypertension Idiopathic / genetic Hypertrophic cardiomyopathy Hyperthyroidism

5 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 Cause of facial paralysis: Possible embolism to the brain (stroke) from the aortic thrombus

6 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

7 Case 2 Description 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

8 Case 2 Morphologic Diagnosis Subaortic stenosis, severe with poststenotic dilation Left ventricular hypertrophy, moderate to marked Valvular endocarditis, rupture, and tract formation Mitral valve dysplasia

9 Case 2 Describe the hemodynamic alterations resulting from the primary lesion and relate them back to the other findings? 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

10 Case 2 Can you relate the lesions back to the clinical findings / history? 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

11 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 abdominocentesis transudate A 3 rd degree heart block was detected (ECG) the owners opted for euthanasia

12 Case 3 Description 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.

13 Case 3 What time of disease process is this? Malignant Neoplasia What are some differentials for this lesion? Hemangiosarcoma Rhabdomyosarcoma Chemodectoma Aortic body tumour Carotid body tumour Ectopic thyroid carcinoma Lymphoma How would you reach a final diagnosis? Histology!

14 Case 3 Morph Diagnosis Hemangiosarcoma, right atrium and lung

15 Case 3 Morph Diagnosis Hemangiosarcoma, right atrium and lung 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 3 rd 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

16 Case 3 What is a more common outcome for these tumours? RA rupture hemopericardium cardiac tamponade PBVD, Saunders, 2017

17 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

18 Case 4

19 Case 4 Description 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 Morph Diagnosis Organizing fibrinous pericarditis, diffuse, chronic, severe Biventricular hypertrophy Bronchopneumonia and fibrous adhesions

20 Case 4 Possible etiology? Bacterial infection (sepsis) Trueperella pyogenes Pasteurella multocida Staphylococcus aureus E coli Submit a swab for bacteriology Antibiotic treatment may hamper microbial growth 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)

21 Case 5 Signalment: 21 year old horse Clinical History: Donated to AVC Poor dentition and weight loss Recurrent bouts of colic

22 Case 5 Description 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 Morph Diagnosis Arteritis, proliferative, segmental, chronic, severe, with dilation (aneurysm) and fibrosis Etiology Strongylus vulgaris (L4) migration

23 Case 5 Description 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 Morph Diagnosis Arteritis, proliferative, segmental, chronic, severe, with dilation (aneurysm) and fibrosis Etiology Strongylus vulgaris (L4) migration

24 Case 5 How might this result in colic? Thrombosis can result in infarction of the intestine (collateral circulation makes this less likely) 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

25 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

26 Case 6

27 Case 6

28 Case 6 Description 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)

29 Case 6 Morphologic Diagnoses Pulmonic Stenosis Ventricular septal defect Right and left ventricular hypertrophy Over-riding aorta Patent ductus arteriosis Patent foramen ovale (~ASD)

30 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 Pulmonic stenosis Ventricular septal defect Over-riding aorta Right ventricular hypertrophy Which of these are congenital and which are acquired? Congenital Acquired Pentology of Fallot Patent foramen ovale OR Patent Ductus Arteriosis

31 Case 6 What are the hemodynamic alterations in this case? R to L shunt through VSD Cyanosis Pulmonic stenosis RV pressure overload RV hypertrophy Right heart failure Shunt through the ASD and PDA? PDA and ASD are not though to contribute much to clinical disease when present along with tetralogy

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