Lab 12

Question 1

Describe this lesion.

Answer 1

The apex of the heart is slightly rounded. On cut surface, the left ventricular wall is slightly thickended. Proximal to the aortic valve is a circumferential fibrotic ring. Distal to the aortic valve, the aorta is dilated. There is a slit-like ventricular septal defect in between the fibrous ring and aortic valve. The AV valves also contain sevveral small nodules

Question 2

What is the blue arrow pointing to?

Answer 2

aortic valve

Question 3

What is the red arrow pointing to?

Answer 3

a subaortic stenosis

Question 4

Provide a morphological diagnosis for this lesion.

Answer 4

Aortic valve: chronic, focal, sub-aortic stenosis with post-stenotic aortic dilation. Left Ventricle: Chronic, diffuse, mild, concentric hypertrophy

Question 5

A heart murmur (4/5) was heard in this puppy’s examination, how does that related to this lesion?

Answer 5

The aortic valve is situated on the left side of the canine. Turbulent blood flow through the aortic stenosis during systole causes vibration of the tissue creating the murmur

Question 6

What is the primary pathologic change in this case?

Answer 6

subaortic stenosis

Question 7

What is the secondary or compensatory change in this lesion?

Answer 7

concentric hypertrophy caused by pressure overload in the left ventricle as well as aortic ballooning

Question 8

Is this case an example of systolic or diastolic dysfunction and why?

Answer 8

systolic, the subaortic stenosis obstructs the outflow of the left ventricle making it harder for the heart to pump the appropriate volume of blood out into the aorta

Question 9

Describe this lesion.

Answer 9

The heart appeears enlarged, pericardial adipose tissue is reduced and largely replaced by clear, glistening, gelatinous material. There is a septal defect just ventral to the aortic and pulmonaru valves. The lumen of the left ventricle is dilated, and the left ventricular free wall is subjectively thin

Question 10

What is the red circle?

Answer 10

a high ventricular septal defect

Question 11

Provide a morphological diagnosis for this lesion.

Answer 11

Heart, ventricular septum: focal, chronic, high ventricular septal defect with left ventricular eccentric hypertrophy

Question 12

What is the primary pathologic change in this case?

Answer 12

high ventricular septal defect

Question 13

What are the compensatory changes in this lesion?

Answer 13

left to right shunting, volume overload causing eccentric hypertrophy of the left atrium and ventricle

Question 14

How is the blood flow altered in this lesion?

Answer 14

the blood will be shunted from the left side to the right side of the heart

Question 15

Is this case an example of systolic or diastolic dysfunction and why?

Answer 15

systolic dysfunction - during systole, the blood is forced from the left ventricle into the lower pressure right ventricle

Question 16

Sometimes the blood flow disturbance in this lesion can undergo a reversal, how?

Answer 16

pulmonary hypertension from over perfusion of the lungs will increase pressure in the right ventricle causing the pressure to be greater than the left (blood flows from highest to lowest pressure)

Question 17

Describe this lesion.

Answer 17

The patent ductus arteriousus connects the pulmonary trunk to the aorta. The right ventricular free wall is thickened to almost the same size as the left free ventricular wall

Question 18

Provide a morphological diagnosis for this lesion.

Answer 18

Heart, aorta, and pulmonary trunk: chronic, focal, patent ductus arteriosus with concentric hypertrophy of the right ventricle

Question 19

What is the function of the ductus arteriosus before birth?

Answer 19

it functions to shunt or byplass blood around the fetal lungs (becaise they are not functional and do not participate in gas exchange)

Question 20

How is the blood flow altered in this lesion?

Answer 20

blood will flow from the left atrium to the right atrium causing a volume overload and eccentric hypertrophy which can lead to pulmonary hypertension

Question 21

Describe this lesion.

Answer 21

The heart appears more rounded than normal with a poorly defined apex. The right ventricular free wall is flaccid. On cut surface both ventricles of the heart are moderately dilated. The aortic valve had multiple small white nodules on the surface of the valve. The left AV valve had multiple, small white nodules on the surface

Question 22

Provide a morphological diagnosis for this lesion.

Answer 22

Heart, right and left side: chronic, diffuse, severe, dilated cardiomyopathy

Question 23

What effect does this lesion have on blood flow through the heart?

Answer 23

systolic dysfunction - there is marked eccentric hypertrophy of the atria and ventricles

Question 24

What could this lesion lead to?

Answer 24

biventricular congestive heart failure

Question 25

What is the underlying cause of this lesion?

Answer 25

the cause for dilated cardiomyopathy is unknown

Question 26

Describe this lesion.

Answer 26

Heart: on cut surface, the left ventricular free wall and septum are diffusely thickened. The lumen of the left ventricle is severely reduced. There are also multiple white foci on the pleural surface that penetrate into the pulmonary pleura

Question 27

Provide a morphological diagnosis for this lesion.

Answer 27

Heart, left ventricle: chronic, diffuse, hypertrophic cardiomyopathy (concentric hypertrophy) with left atrial enlargement. Aorta and lungs: multifocal pulmonary and aortic mineralization

Question 28

Is this case an example of systolic or diastolic dysfunction and why?

Answer 28

primarily a diastolic dysfunction however there are systolic dysfunction components

Question 29

Many cats that have this cardiac lesion will present with painful, cold, and paretic hindlimbs. Why is that?

Answer 29

Thrombi form due to the stagnation of blood and leave the left atrium and can get wedged at the bifurcation of the abdominal aorta preventing blood flow to the limbs

Question 30

Describe this lesion.

Answer 30

Enlarged right ventricule and compacted with heart worms that extend up into the pulmonary arteries. There is a mottled tan to red friable material covering the nemotodes. The pulmonary arteries are slightly distended. There are multiple, white round foci on the pleural sirface

Question 31

Provide a morphological diagnosis for this lesion.

Answer 31

Heart, right ventricle: chronic, focal, concentric hypertrophy with intralesional nematode parasites. Lungs: chronic, multifocal, pale white foci

Question 32

What disease causes this lesion?

Answer 32

heartworm - dirofilaria immitis

Question 33

What is cor pulmonale?

Answer 33

enlargement and failure of the right-side of the heart as a result of pulmonary hypertension causing concentric hypertrophy, ascites, hepatic congestion, hydrothorax, and peripheral edema

Question 34

How is cor pulmonale play into the pathogenesis of heartworm?

Answer 34

The presence of the worm in the vasculature is irritating and results in proliferation of the tunica intima, vascular sclerosis, and vascular fibrosis of the pulmonary vessels. Fibrosis of the pulmonary vasculature result in pulmonary hypertension. Pulmonary hypertension and the physical presence of the nematodes in the pulmonary vasculature can increase the pressure load on the right side of the heart which will lead to right side heart failure

Question 35

Describe this lesion.

Answer 35

the subpericardium is characterized by multifocal to coalescing areas of hemorrhage. There are widely disseminated streaks of myocardial pallor. On cut surface, the area of hemorrhage and pallow penetrate into the myocardium

Question 36

Histology revealed swollen, fragmented, hypereosinophilic degenerate and necrotic cardiomyocytes. Provide a morphologic diagnosis considering both the histology and gross findings.

Answer 36

Heart: myocardial necrosis and hemorrhage, acute, multifocal to widely disseminated

Question 37

What is the common name for this lesion?

Answer 37

mulberry heart disease

Question 38

What is a likely etiology for these lesions and the cause of death in this animal?

Answer 38

Vitamin E or selenium deficiency is thought to cause this. Necrosis of the vasculature results in hemorrhage and thrombus formation. Thrombus formation in small vessels can result in infarction and necrosis