Lecture 3 Flashcards
Describe the components of the heart
÷ Pericardium
÷ Myocardium
÷ Conduction system
÷ Endocardium & Valves
Describe the components of the heart vessels
÷ Arteries (distribution)
÷ Veins (collection)
÷ Capillaries
÷ Lymphatic
How is fluid distribution and homeostasis maintained
Physical barriers
Concentration Gradient
Pressure Gradient
What is edema
Accumulation of excess interstitial fluid
What are the barrier problems
increased permeability
What enzymes are associated with inflammation
histamine and bradykinin
What can cause barrier problems
inflammation, damage and immune mediated
What causes edema
infectious (tick born disease, FIP, leptospirosis, etc)
immune mediated disease
toxins
What causes hydrostatic pressure problems
portal hypertension
localized obstruction
fluid overload
What does hydrostatic pressure mean
increased pressure
what causes oncotic pressure problems
decreased albumin (production or losses)
What are common fluid distribution problems
Barrier Problems
Pressure Problems
Decreased lymphatic drainage
Where can edema be located
¡ Alveolar lumen ¡ Thoracic cavity ¡ Pericardial sac ¡ Abdominal cavity ¡ Subcutaneous
Describe the appearance of edema and the histological appearance
Clear to slightly yellow
transuadate (low protein and low cells)
Describe physical disruption that cause hemorrhage
trauma
erosion
neoplastic invasion
fungi
What minor defects that could cause hemorrhage
endotoxemia/infectious agents
toxins
immune-complexes
What can cause hemorrhage
Physical disruption
minor defects
thrombocytopenia
coagulation factor deficiency
What is thrombosis
Formation of inappropriate clot of fibrin and/or platelets along with other blood elements on the wall of a blood vessel / lymphatic / heart.
What is a thrombosis called when it occurs in the lumen
thromboembolism
What can cause endothelial injury/vasculitis
¡ Infectious (ex herpes virus, salmonella, aspergillus)
¡ Immune-mediated
¡ Toxins
What can cause an alteration in blood flow
¡ Mechanical
÷ (GDV, external compression)
¡ Cardiac disease
¡ Hypovolemia
What can cause hypercoagulability
¡ Inflammation ¡ Diabete ¡ Renal disease ¡ Neoplasia ¡ Hepatic disease ¡ Cushing’s ¡ Hypothyroidism ¡ Heartworm
What are the clinical signs of thromboembolism in the renal arteries
decrease in renal function, proteinuria and hematuria or
anuria if bilateral
what are the clinical signs of thromboembolism in the pulmonary arteries
¡ acute respiratory compromise and a ventilation-perfusion mismatch that can be mild or subclinical depending on the degree of embolization
what are the clinical signs of thromboembolism in the mesenteric arteries
¡ gastrointestinal signs and abdominal pain
what are the clinical signs of thromboembolism in the distal limb arteries
¡ pain, hardening of the musculature (tetany), and cyanosis
What are the three types of shock
¡ Cardiogenic ¡ Hypovolemic ¡ Blood maldistribution (÷ Septic ÷ Anaphylactic ÷ Neurogenic)
What is cariogenic shock
Failure of the heart to pump adequate amount of blood ÷ Arrhythmias ÷ Cardiomyopathy ÷ Pericardial tamponade ÷ Anesthesia
How is cardiogenic shock characterized
Loud murmurs, tachycardia or bradycardia, arrrhythmias, and weak heart sounds
What is hypovolemic shock
¡ Reduced circulating blood volume
÷ Fluid loss: vomiting, diarrhea, burns
÷ Blood loss (>35%)
How is hypovolemic shock characterized
tachycardia, pale mucous membranes, and tachypnea
What is blood maldistribution
¡ Pooling of blood in peripheral tissues from vasodilation
what is anaphylactic shock
¡ Widespread mast cell degranulation
¡ USUALLY CAUSED BY: Vaccine, insect/plant, drugs
What is neurogenic shock
¡ Autonomic nerve discharge
¡ CAUSED BY: Electrocution, stress, fear
What is septic shock
¡ Infectious organism released inflammation mediator
What is congestive heart failure
Inability of the heart to maintain normal
¡ systemic blood pressure
¡ normal cardiac output (normal tissue blood flow)
¡ normal filling pressure
Why does congestive heart failure occur
results from severe heart disease
What does right sided heart failure cause
¡ Hepatomegaly & splenomegaly ¡ Ascites
What does left sided heart failure cause
Pulmonary congestion and edema
What can cause pericardial effusion
¡ Cardiac hemangiosarcoma ÷ Highly malignant ¡ Idiopathic ÷ Golden Retriever ¡ Acute vs Chronic ¡ Pericardiocenthesis
Describe dilated cardiomyopathy
¡ Large breed dog (e.g. Doberman, Irish Wolfhound)
¡ Familial pattern
¡ Etiology not well understood
¡ Adult onset
÷ May have murmur, arrhythmias, tachycardia
¡ Taurine-deficient cats
Describe myocardium
Hypertrophic cardiomyopathy
¡ Main Coons
¡ Etiology not completely clear
¡ Young adult, middle-age cat
÷ Mostly asymptomatic with murmur of gallop
¡ Associated with arterial thromboembolism
¡ Hyperthyroidism can cause a form of DCM (reversible)
Describe arrhythmogenic cardiomyopathy of the boxer
¡ Ventricular arrhythmias, syncope, sudden death
¡ Familial disease
÷ Not well understood, difficult to breed out
Describe sick sinus syndrome
¡ West Highland white terrier, Miniature schnauzer, American
cocker spaniel, Boxer, Dachshund, Pug
¡ Idiopathic
¡ Adult onset
÷ Most of these dogs show overt clinical signs (syncope, episodic
weakness) at the time of diagnosis
¡ Pacemaker
Describe myxomatous valvular degeneration
¡ Progressive degeneration of the atrioventricular valves
¡ Older dogs
¡ Small- to medium-size breeds (Papillon, Poodle, Chihuahua,
Dachshund, Cavalier King Charles Spaniel)
¡ Slow progression to heart failure
¡ Progressive murmur
Describe patent ductus arteriosus
¡ Mostly dogs ¡ Congenital, can be genetic ¡ Female; pomeranian, poodle (proved heritable cause), Keeshond, Bichon frise, Chihuahua, Maltese, Shetland sheepdog ¡ Continuous murmur ¡ Sx or Coil
Describe valve stenosis
¡ Pulmonary valve (smaller breeds)
¡ Aortic valve (larger breeds)
¡ Loud murmur
¡ Not as easy to correct if severe
describe fibrocartilaginous embolism
¡ Vascular thrombosis and infarction of the spinal cord
¡ Sudden onset, usually one side worst
¡ Non-chondrodystrophoid
¡ If deep pain sensation remains, many animals will recover useful spinal function
describe intestinal lymphangiectasia
Dilatation of lymphatic vessels and obstruction of normal
lymph flow.
¡ Intestinal lymphatic dysfunction leads to leakage of protein- rich lymph into the intestinal lumen.
÷ Common causes of protein-losing enteropathy (PLE) in dogs
¡ Primary: idiopathic
¡ Secondary:
÷ Inflammatory disease ÷ Neoplasia
÷ Heart failure
What are the signs of intestinal lymphangiectasia
÷ vomiting, diarrhea (usually small bowel), weight loss, lethargy, anorexia
÷ peripheral edema, abdominal distension from ascites
How do you treat intestinal lymphangiectasia
diet change, anti-inflammatories
what is the prognosis for intestinal lymphangiectasia
prognosis is variable
What causes a rupture of the thoracic duct
¡ Cause chylothorax
¡ Cytological aspect:
¡ Often idiopathic (other: neoplasia, HWD, heart failure)
What is a portosystemic shunt
¡ Anomalous vessels that allow normal portal blood (from GIT) to pass directly into the systemic circulation without first passing through the liver
¡ Congenital or acquired (older)
¡ Failure to thrive, poor weight gain, and small body stature ÷ Seizure-like episodes after a meal
¡ Some can be treated with surgery
