Cardiac Pathology Flashcards
What brown granular pigment can be found in cardiac muscle that is considered normal?
Lipofuscin. Its presence is age related.
What are the reversible/sublethal cardiovascular responses to injury?
Inflammation, haemorrhage, adaptation (atrophy, hypertrophy), fatty degeneration/infiltration, lipofuscin, vacuolar degeneration.
What are the irreversible cardiac responses to injury?
Necrosis (apoptosis), leukocyte infiltration and phagocytosis, repair by fibrosis.
Why is maintenance of cardiac output important?
Supply peripheral tissues with oxygen and nutrients. Remove carbon dioxide and wastes. Maintain GFR and thermoregulation.
What are the compensatory mechanisms of cardiovascular disease?
Cardiac dilation, myocardial hypertrophy, increased heart rate, increased peripheral resistance, increased blood volume, redistributed blood flow.
What are the features of eccentric hypertrophy and what causes it?
Enlarged ventricular chamber, wall is normal-decreased in thickness. Caused by increased blood volume (valvular insufficiencies, septal defects).
What are the features of concentric hypertrophy and what causes it?
Smaller ventricular chamber with thickened wall. Caused by increased pressure load (valvular stenosis, systemic hypertension, pulmonary disease).
What is cardiac syncope?
Acute collapse and loss of consciousness due to extreme changes in heart rate and blood pressure.
What is forward congestive cardiac failure?
Decreased blood flow forward to peripheral tissue
What is backward congestive cardiac failure?
Accumulation of blood behind the failing chamber
What pathology is seen in acute left-sided congestive cardiac failure?
Pulmonary congestion and oedema
What pathology is seen in chronic left-sided congestive cardiac failure?
Chronic, passive pulmonary congestion and oedema. Alveolar macrophages with haemosiderin (heart failure cells). Pulmonary fibrosis.
What are the causes of left-sided congestive cardiac failure?
Loss of contractility.
Dysfunction of mitral or aortic valves.
Severe congenital heart disease.
What pathology will be seen in acute right-sided congestive cardiac failure?
Acute systemic congestion (hepatomegaly, splenomegaly)
What pathology will you see in chronic right-sided congestive cardiac failure?
Chronic systemic congestion (nutmeg liver).
Severe sodium and water retention (Ascites in dogs, hydrothorax in cats).
What are the causes of right-sided congestive cardiac failure?
Pulmonary hypertension, cardiomyopathy, dysfunction of tricuspid or pulmonary valve, Pimelea simplex.
What is a patent ductus arteriosus and what is the resulting pathology?
Vascular channel between the aorta and pulmonary artery does not close after birth and causes pulmonary hypertension.
What is an atrial septal defect?
Defect in the atrial septum, may be due to failure of closure of the foramen ovale.
What four lesions are involved in tetralogy of fallot?
Pulmonic stenosis.
Ventricular septal defect.
Dextraposition of the aorta.
2° hypertrophy of right ventricular myocardium.
Which type of cardiac hypertrophy occurs as a consequence of pulmonic stenosis?
Right ventricular concentric hypertrophy
What type of cardiac hypertrophy would occur as a consequence of aortic stenosis?
Left ventricular concentric hypertrophy
What type of cardiac hypertrophy would occur as a consequence of ventricular septal defect?
Right sided ventricular eccentric hypertrophy
What is gout caused by?
Uric acid deposits
What type of pericarditis does hardware disease cause?
Suppurative pericarditis
Endocardial mineralisation can be caused by?
Excess dietary Vit. D
Calcinogenic plants
Endocardial fibrosis can be causes by?
Chronically dilated hearts
Debilitated cattle with Johne’s diseases
Dogs with healed endocarditis lesions
Jet lesions from valvular insufficiencies
Explain the main differences between endocardiosis and endocarditis.
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.
Outline the pathogenesis of endocarditis
Complicated - involves Virchow’s triad of thrombogenesis (endothelial injury, turbulence, hypercoagulability)
Affected animals often have gingivitis, dermatitis, etc
(causes the bouts of bacteraemia)
What are the main mechanisms of hydropericardium?
Congestive heart failure
Pulmonary hypertension
Hypoproteinaema
Systemic vascular injury
What are four key histological features of normal cardiac muscle?
Branched cells, central nuclei, striated, intercalated disks
What types of myocardial degeneration and give brief summary?
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)
Name the different types of myocarditis and give an example of what causes them?
Suppurative (pyogenic bacteria), Necrotising (toxoplasmosis), Haemorrhagic (clostridium chauvoei), Lymphocytic (viruses), Eosinophilic (sarcocystis)
How does myocardium heal?
By fibrosis
List the primary cardiomyopathies
Hypertrophic, Dilated and Restrictive
List the secondary cardiomyopathies
systemic, endocrine, heritable, nutritional, toxic, infectious, neoplastic
Dilated cardiomyopathies tend to be more common in animals with what deficiency?
Taurine
What is the most common primary mycardial neoplasia?
Haemangiosarcoma
What is an aneurism?
Localised dilation/outpouch of thin/weak vessel wall
What can cause an aneurism?
idiopathic, Cu deficiency in pigs, strongylus vulgaris, spirocerca lupi
How does a dissecting aneurism occur?
Disruption of intima allows blood into the media which dissects along the wall
In which species is rupture of anuerisms particularly imporant?
Horses - rupture is often fatal
What is the cause of arterial hypertrophy?
Sustained pressure or volume
Intimal fibrosis of large elastic arteries is called
Arteriosclerosis
Intimal and medial lipid deposition in elastic and muscular arteries is called
Atherosclerosis
What is the effect of arteriosclerosis?
Loss of elasticity - “hardening of arteries”
What is the main effect of atherosclerosis?
narrowing of the lumen
Basophilic granular mineral deposits in the walls of arteries occur in
Arterial medial calcification
Arterial fibrinoid necrosis is associated with what?
Endothelial damage
What causes mulberry heart disease?
Selenium / Vitamin E deficiency
Acute degeneration / inflammation of small arteries / arterioles
Fibrinoid Necrosis
What is arteritis?
Arterial inflammation
What can cause arteritis?
infection, immune mediated diseases, local extension of inflammation
Leukocytes within and surrounding vessels is a feature of?
Arteritis
What is involved in Virchow’s Triad?
Hypercoagulability, endothelial damage, turbulence / stasis
What is an embolism?
Something foreign moving in the vascular system
Dogs with dirofilariasis get what type of thrombosis?
Pulmonary artery thrombosis
Horses with Strongylus vulgaris get what type of thrombosis?
Mesenteric & Intestinal Arterial Thrombosis
A cat in lame in the hind legs - caudal extremities are cold. What is the most likely cause?
Caudal aortic “saddle” thromboembolism
Briefly describe what occurs in disseminated intravascular coagulation
widespread clotting depletes coagulation factors and then widespread haemorrhage occurs
What is phlebitis?
Venous inflammation
What is omphalophlebitis?
inflammation of the umbilical vein
What can cause phlebitis?
Systemic infections, immune complex deposition, extension of localised infections, IV injections
What is lymphangiectasia?
Dilation of lymph vessels
