Cardiac Pathology

Question 1

What brown granular pigment can be found in cardiac muscle that is considered normal?

Answer 1

Lipofuscin. Its presence is age related.

Question 2

What are the reversible/sublethal cardiovascular responses to injury?

Answer 2

Inflammation, haemorrhage, adaptation (atrophy, hypertrophy), fatty degeneration/infiltration, lipofuscin, vacuolar degeneration.

Question 3

What are the irreversible cardiac responses to injury?

Answer 3

Necrosis (apoptosis), leukocyte infiltration and phagocytosis, repair by fibrosis.

Question 4

Why is maintenance of cardiac output important?

Answer 4

Supply peripheral tissues with oxygen and nutrients. Remove carbon dioxide and wastes. Maintain GFR and thermoregulation.

Question 5

What are the compensatory mechanisms of cardiovascular disease?

Answer 5

Cardiac dilation, myocardial hypertrophy, increased heart rate, increased peripheral resistance, increased blood volume, redistributed blood flow.

Question 6

What are the features of eccentric hypertrophy and what causes it?

Answer 6

Enlarged ventricular chamber, wall is normal-decreased in thickness. Caused by increased blood volume (valvular insufficiencies, septal defects).

Question 7

What are the features of concentric hypertrophy and what causes it?

Answer 7

Smaller ventricular chamber with thickened wall. Caused by increased pressure load (valvular stenosis, systemic hypertension, pulmonary disease).

Question 8

What is cardiac syncope?

Answer 8

Acute collapse and loss of consciousness due to extreme changes in heart rate and blood pressure.

Question 9

What is forward congestive cardiac failure?

Answer 9

Decreased blood flow forward to peripheral tissue

Question 10

What is backward congestive cardiac failure?

Answer 10

Accumulation of blood behind the failing chamber

Question 11

What pathology is seen in acute left-sided congestive cardiac failure?

Answer 11

Pulmonary congestion and oedema

Question 12

What pathology is seen in chronic left-sided congestive cardiac failure?

Answer 12

Chronic, passive pulmonary congestion and oedema. Alveolar macrophages with haemosiderin (heart failure cells). Pulmonary fibrosis.

Question 13

What are the causes of left-sided congestive cardiac failure?

Answer 13

Loss of contractility.
Dysfunction of mitral or aortic valves.
Severe congenital heart disease.

Question 14

What pathology will be seen in acute right-sided congestive cardiac failure?

Answer 14

Acute systemic congestion (hepatomegaly, splenomegaly)

Question 15

What pathology will you see in chronic right-sided congestive cardiac failure?

Answer 15

Chronic systemic congestion (nutmeg liver).

Severe sodium and water retention (Ascites in dogs, hydrothorax in cats).

Question 16

What are the causes of right-sided congestive cardiac failure?

Answer 16

Pulmonary hypertension, cardiomyopathy, dysfunction of tricuspid or pulmonary valve, Pimelea simplex.

Question 17

What is a patent ductus arteriosus and what is the resulting pathology?

Answer 17

Vascular channel between the aorta and pulmonary artery does not close after birth and causes pulmonary hypertension.

Question 18

What is an atrial septal defect?

Answer 18

Defect in the atrial septum, may be due to failure of closure of the foramen ovale.

Question 19

What four lesions are involved in tetralogy of fallot?

Answer 19

Pulmonic stenosis.
Ventricular septal defect.
Dextraposition of the aorta.
2° hypertrophy of right ventricular myocardium.

Question 20

Which type of cardiac hypertrophy occurs as a consequence of pulmonic stenosis?

Answer 20

Right ventricular concentric hypertrophy

Question 21

What type of cardiac hypertrophy would occur as a consequence of aortic stenosis?

Answer 21

Left ventricular concentric hypertrophy

Question 22

What type of cardiac hypertrophy would occur as a consequence of ventricular septal defect?

Answer 22

Right sided ventricular eccentric hypertrophy

Question 23

What is gout caused by?

Answer 23

Uric acid deposits

Question 24

What type of pericarditis does hardware disease cause?

Answer 24

Suppurative pericarditis

Question 25

Endocardial mineralisation can be caused by?

Answer 25

Excess dietary Vit. D | Calcinogenic plants

Question 26

Endocardial fibrosis can be causes by?

Answer 26

Chronically dilated hearts Debilitated cattle with Johne's diseases Dogs with healed endocarditis lesions Jet lesions from valvular insufficiencies

Question 27

Explain the main differences between endocardiosis and endocarditis.

Answer 27

Endocardiosis is a degenerative disease caused by degeneration of collagen. Nodules are smooth and shiny. Endocarditis is an inflammatory disease usually due to bacterial diseases. Layers of fibrin and bacterial colonies over inflamed granulation tissue.

Question 28

Outline the pathogenesis of endocarditis

Answer 28

Complicated - involves Virchow's triad of thrombogenesis (endothelial injury, turbulence, hypercoagulability) Affected animals often have gingivitis, dermatitis, etc (causes the bouts of bacteraemia)

Question 29

What are the main mechanisms of hydropericardium?

Answer 29

Congestive heart failure Pulmonary hypertension Hypoproteinaema Systemic vascular injury

Question 30

What are four key histological features of normal cardiac muscle?

Answer 30

Branched cells, central nuclei, striated, intercalated disks

Question 31

What types of myocardial degeneration and give brief summary?

Answer 31

Fatty change (lipid droplets in sarcoplasm of cardiomyocytes), hydropic degeneration (vacuolation of sarcoplasm and lysis of contractile material), Lipofuscinosis (age related pigment), Myofibril degeneration (pale, eosinophilic sarcoplasm lacking striations)

Question 32

Name the different types of myocarditis and give an example of what causes them?

Answer 32

Suppurative (pyogenic bacteria), Necrotising (toxoplasmosis), Haemorrhagic (clostridium chauvoei), Lymphocytic (viruses), Eosinophilic (sarcocystis)

Question 33

How does myocardium heal?

Answer 33

By fibrosis

Question 34

List the primary cardiomyopathies

Answer 34

Hypertrophic, Dilated and Restrictive

Question 35

List the secondary cardiomyopathies

Answer 35

systemic, endocrine, heritable, nutritional, toxic, infectious, neoplastic

Question 36

Dilated cardiomyopathies tend to be more common in animals with what deficiency?

Answer 36

Taurine

Question 37

What is the most common primary mycardial neoplasia?

Answer 37

Haemangiosarcoma

Question 38

What is an aneurism?

Answer 38

Localised dilation/outpouch of thin/weak vessel wall

Question 39

What can cause an aneurism?

Answer 39

idiopathic, Cu deficiency in pigs, strongylus vulgaris, spirocerca lupi

Question 40

How does a dissecting aneurism occur?

Answer 40

Disruption of intima allows blood into the media which dissects along the wall

Question 41

In which species is rupture of anuerisms particularly imporant?

Answer 41

Horses - rupture is often fatal

Question 42

What is the cause of arterial hypertrophy?

Answer 42

Sustained pressure or volume

Question 43

Intimal fibrosis of large elastic arteries is called

Answer 43

Arteriosclerosis

Question 44

Intimal and medial lipid deposition in elastic and muscular arteries is called

Answer 44

Atherosclerosis

Question 45

What is the effect of arteriosclerosis?

Answer 45

Loss of elasticity - "hardening of arteries"

Question 46

What is the main effect of atherosclerosis?

Answer 46

narrowing of the lumen

Question 47

Basophilic granular mineral deposits in the walls of arteries occur in

Answer 47

Arterial medial calcification

Question 48

Arterial fibrinoid necrosis is associated with what?

Answer 48

Endothelial damage

Question 49

What causes mulberry heart disease?

Answer 49

Selenium / Vitamin E deficiency

Question 50

Acute degeneration / inflammation of small arteries / arterioles

Answer 50

Fibrinoid Necrosis

Question 51

What is arteritis?

Answer 51

Arterial inflammation

Question 52

What can cause arteritis?

Answer 52

infection, immune mediated diseases, local extension of inflammation

Question 53

Leukocytes within and surrounding vessels is a feature of?

Answer 53

Arteritis

Question 54

What is involved in Virchow's Triad?

Answer 54

Hypercoagulability, endothelial damage, turbulence / stasis

Question 55

What is an embolism?

Answer 55

Something foreign moving in the vascular system

Question 56

Dogs with dirofilariasis get what type of thrombosis?

Answer 56

Pulmonary artery thrombosis

Question 57

Horses with Strongylus vulgaris get what type of thrombosis?

Answer 57

Mesenteric & Intestinal Arterial Thrombosis

Question 58

A cat in lame in the hind legs - caudal extremities are cold. What is the most likely cause?

Answer 58

Caudal aortic "saddle" thromboembolism

Question 59

Briefly describe what occurs in disseminated intravascular coagulation

Answer 59

widespread clotting depletes coagulation factors and then widespread haemorrhage occurs

Question 60

What is phlebitis?

Answer 60

Venous inflammation

Question 61

What is omphalophlebitis?

Answer 61

inflammation of the umbilical vein

Question 62

What can cause phlebitis?

Answer 62

Systemic infections, immune complex deposition, extension of localised infections, IV injections

Question 63

What is lymphangiectasia?

Answer 63

Dilation of lymph vessels