Lecture 19

Question 1

What are the characteristics of pulmonic stenosis?

Answer 1

-congenital obstruction to the right ventricular outflow tract
-most commonly valvular
-subvalvular or supravalvular stenosis is less common
-heritable basis proven in beagles and keeshonds
-other at risk breeds include english bulldog, mastiff, samoyed, mini schnauzer, american cocker spaniel, and west highland white terrier

Question 2

What is the pathogenesis behind the changes seen in pulmonic stenosis?

Answer 2

-ventricle must work harder to push blood through narrowed outflow tract
-results in thickened right ventricle and dilated pulmonary artery

Question 3

What are the radiographic findings of pulmonic stenosis?

Answer 3

-right heart enlargement (RVE +/- RAE) due to pressure overload
-main pulmonary artery segment enlargement
-normal to small pulmonary vessels
-possible right heart failure

Question 4

What is shown in these images?

Answer 4

pulmonic stenosis
-right heart enlargement
-main pulmonary artery segment enlargement
-possible right heart failure

Question 5

What are the characteristics of subaortic or aortic stenosis?

Answer 5

-congenital obstruction to left ventricular outflow tract
-most commonly subvalvular; > 95% are subaortic stenosis
-heritable basis in newfoundlands
-other common breeds include rottweilers, boxers, golden retrievers, and GSDs

Question 6

What are the findings radiographic findings in subaortic stenosis?

Answer 6

-survey rads may be normal
-left heart enlargement (LVE +/- LAE) due to pressure overload
-elongation of cardiac silhouette
-increased prominence of aortic arch
-very low incidence of left heart failure

Question 7

What is shown in these images?

Answer 7

(sub)aortic stenosis
-left heart enlargement
-elongation of cardiac silhouette
-increased prominence of aortic arch

Question 8

What are the characteristics of patent ductus arteriosis?

Answer 8

-failure of ductus arteriosus to close after birth
-persistent shunt between aorta and main pulmonary artery
-shunting initially left-to-right; may change to right-to-left
-heritable basis in toy/mini poodles, GSDs, collies, pomeranians, shetland sheep dogs, maltese, english springer spaniels, keeshonds, and yorkies

Question 9

What are the radiographic findings in patent ductus arteriosis?

Answer 9

*LVE and LAE due to volume overload
*normal to large pulmonary vessels
*possible left heart failure
*triple bump sign:
-aneurysmal dilatation of proximal descending aorta
-MPA segment enlargement
-enlargement of left auricle

Question 10

What is shown in these images?

Answer 10

patent ductus arteriosus
-LVE and LAE
-normal to large pulmonary vessels
-triple bump sign

Question 11

What is heartworm disease?

Answer 11

presence of filarial nematodes (Dirofilaria immitis) in the pulmonary arteries +/- right heart

Question 12

What are the radiographic signs of heartworm disease?

Answer 12

*RVE and RAE
*enlarged MPA segment
*enlarged, pruned, and tortuous pulmonary arteries
*possible right heart failure
*pulmonary infiltrates:
-mixed pulmonary patterns
-evidence of pulmonary thromboembolism

Question 13

What is shown in these images?

Answer 13

heartworm disease:
-RVE and RAE
-enlarged MPA segment
-enlarged pulmonary arteries
-pulmonary infiltrates

Question 14

What are the characteristics of canine cardiomyopathy?

Answer 14

-almost exclusively dilated form
-myocardial failure
-ventricles undergo volume overload and eccentric hypertrophy
-mostly a disease of large breed dogs
-predisposed in dobermans, boxers, great danes, and labs
-generalized cardiomegaly +/- left, right, or biventricular heart failure

Question 15

What is shown in these images?

Answer 15

dilated cardiomyopathy:
-generalized cardiomegaly
-possible heart failure

Question 16

What are the types of feline cardiomyopathies?

Answer 16

-hypertrophic
-concentric hypertrophy secondary to primary abnormality
-restrictive
-dilated

Question 17

What are the characteristics of hypertrophic cardiomyopathy in cats?

Answer 17

-most common heart disease in cats
-disease of the ventricular (primarily left) myocardium characterized by concentric hypertrophy
-maine coons predisposed but seen in other breeds and mixed breeds

Question 18

What are the characteristics of dilated cardiomyopathy in cats?

Answer 18

-rare today since association with taurine deficiency is now known
-congenital in some exotic cat breeds

Question 19

What is important regarding feline cardiomyopathy and radiographs?

Answer 19

the type of cardiomyopathy cannot be distinguished radiographically

Question 20

What is shown in these images?

Answer 20

feline cardiomyopathy

Question 21

What is shown in these images?

Answer 21

feline cardiomyopathy

Question 22

What are the characteristics of endocardiosis/myxomatous atrioventricular valvular degeneration?

Answer 22

-most common cardiovascular disease in dogs
-degenerative disease process resulting in thickening and redundancy of mitral and tricuspid valve leaflets and lengthening of cordae tendinae
-results in mitral and/or tricuspid insufficiency and regurgitation
-predominantly affects old, small breed dogs

Question 23

What is the distribution of endocardiosis cases based on valve involvement?

Answer 23

-60% affect mitral valve only (left side)
-10% affect tricuspid valve only (right side)
-30% affect both valves

Question 24

What are the radiographic signs of endocardiosis based on valve involvement?

Answer 24

*mitral insufficiency (left side):
-LAE
-LVE
-possible left heart failure

*tricuspid insufficiency (right side):
-RAE
-RVE
-possible right heart failure

*right and left AV valves:
-generalized cardiomegaly
-possible right and/or left heart failure

Question 25

What is shown in these images?

Answer 25

endocardiosis

Question 26

What are the subcategories of cardiac neoplasia?

Answer 26

*epicardial -mesothelioma -hemangiosarcoma *mural -hemangiosarcoma -lymphosarcoma *intracavitary -hemangiosarcoma *heart base -chemodectoma

Question 27

What are the characteristics of cardiac neoplasia?

Answer 27

-survey rads may be normal or show non-specific findings -intracavitary tumors are predominantly located within right atrium and may cause RAE in severe cases -heart base tumors might have an evident mass in the cranial dorsal mediastinum causing dorsal and rightward displacement of the trachea

Question 28

What is shown in these images?

Answer 28

heart base tumor

Question 29

What are the characteristics of pericardial effusion?

Answer 29

-presence of fluid within pericardial sac -spherically enlarged, globoid cardiac silhouette -lack of discrete chamber definition -must differentiate from generalized cardiomegaly -may cause right heart failure -NEVER causes left heart failure -may see pulmonary metastases

Question 30

What is shown in these images?

Answer 30

pericardial effusion

Question 31

What are the characteristics of peritoneo-pericardial diaphragmatic hernia?

Answer 31

-abnormality in embryogenesis of ventral portion of diaphragm -results in persistent communication between peritoneal cavity and pericardial sac -commonly associated with sternal abnormalities -often diagnosed incidentally -clinical signs include cardiac tamponade or GI signs

Question 32

What are the radiographic findings in peritoneal-pericardial diaphragmatic hernia?

Answer 32

-enlarged, globoid or abnormally shaped cardiac silhouette -silhouetting of cardiac silhouette and diaphragm -may see gas-filled bowel loops or fat in chest -possible "empty abdomen"/missing abdominal organs or small liver -possible concurrent sternal anomaly

Question 33

What is shown in these images?

Answer 33

peritoneo-pericardial diaphragmatic hernia