CV Pathology Flashcards
I, II, III, IV and V
Define dilation
a response to an increased workload. This can be transient (e.g. when performing exercise) or persistent
Define hypertrophy
the reversible increased in the mass of the heart cells without increasing in number.
What are the two types of hypertrophy ?
concentric (pressure overload)
- no increased in ventricular volume
eccentric (volume overload)
- increase in ventricular volume
Name the three arteriovenous connections present in embryology
ductus arteriosus
foramen ovale
ventricular holes
What are the sequelae of left-to-right shunting
volume overload of the pulmonary circulation –> left sided eccentric hypertrophy
Clinical signs of left-to-right shunting
exercise intolerance
syncope
dyspnoea
sudden death
murmur (“washing machine”)
Define patent ductus arteriosus
a connection between the pulmonary artery and the aorta
Define arterial septal defects
a connection between the two atria, allowing blood to pass between them
Define ventricular septal defects
can happen anywhere along the septum, can be perimembranous or muscular. causes insufficiency
Define stenotic diseases
diseases affecting the semilunar valves
may be pulmonic or aortic (or subaortic)
increases afterload
Define dysplastic valvular diseases
involve the AV valves
increases preload
What is a transposition complex and name the most common
malpositioning of arterial trunks
overriding aorta most common (aorta straddles septum and recieves blood from both ventricles)
may also see partial transposition, overriding pulmonary artery and complete transposition
Define and give the characteristic features of primary myocardial disease
idiopathic diseases to the myocardial fibre.
characterized by cardiomegaly (increased %BW of heart), increased ventricular wall thickness and mural thrombosis
Define DCM
dilated cardiomyopathy
leading to systolic dysfunction
grossly, atria and ventricle dilation and non-specific histo
Define HCM
hypertrophic cardiomyopathy
–> diastolic dysfunction due to impaired ability to relax
leads to ventricular outflow tract obstruction, causing turbulence
grossly, asymmetrical hypertrophy of left ventricle, subtle histo
Define RCM
restrictive cardiomyopathy
–> diastolic dysfunction due to restriction in the ability of the ventricles to fill
grossly, fibrosis, moderator bands and dilated atria with normal ventricles
Define ARVC
arrhythmic right ventricular cardiomyopathy
–> ventricular arrhythmias due to a nerve block
grossly, hypertrophy of ventricle and dilation of atrium
distinctive histology of fibro-fatty replacements of cardiomyocytes
Name some secondary causes of cardiomyopathies
hormone
nutritional
toxin
infectious agents
inflammation
What are the sequelae of secondary cardiomyopathies ?
altered myocyte metabolism (most commonly hyperthyroidism in cats)
myocyte death (myocardial necrosis, white band visible in the muscle (sometimes “white muscle” disease), neurological disease/nutritional (Vit E/selenium)/toxins cause
myocarditis.
- necrotizing
- suppurative
- pyogranulomatous
- eosinophilic
- lymphoplasmacytic
How do cardiomyocytes react to injury ?
regeneration is rare as the cells a post-mitotic
loss results in fibrosis
remaining myocytes have the ability to compensate via hypertrophy
Clinical Signs of conduction disorders
ECG abnormalities, syncope, sudden death
Define endocardiosis
the degenerative disease of the hearts mitral valve (left AV valve). responsible for 75% of all heart diseases in dogs
Myxomatous Valve Degeneration (MVD) :
- most common cause of Cv diseases in dogs
- genetic predisposition for small dogs
- grossly, thickened and shortened valves with a smooth endocardial surface.
- if clinically significant, will see “jet lesions” of fibrosis in the left atrium
- histologically, myofibroblastic proliferation and deposition of acid mucopolysaccharides within valvular stroma
What is the sequelae of endocardiosis ?
valvular insufficiency (regurgitation)
occurs when there is a volume overload
eccentric hypertrophy, dilating the previous chamber and causing these “jet lesions”
mural thrombi may also form attached to the heart wall
Define endocarditis
inflammation of the inner lining of the heart
What is endocarditis commonly caused by ?
bacteria.
commonly, Strep. Staph. E. coli
often associated with extracardiac infections
Gross appearance of endocarditis
friable, yellow-to-grey-to-red masses of fibrin with a roughened surface (“cauliflower-like”), may extend into the mural endocardium in the form of plaques
Define hydropericardium
excess clear fluid within the pericardial cavity
may be caused by decreased oncotic pressure, decreased lymphatic drainage, increased hydrostatic pressure and increased vascular permeability
Define hemopericardium
pure blood in the pericardial cavity
occurs with the rupture of BVs
What are the sequelae for fluid in the pericardial cavity ?
cardiac tamponade (compression of the heart resulting in impaired atrial and ventricular filling)
Define serous atrophy of fat in the heart
lipid is replaced by a proteinaceous fluid
grossly, what should be white fat becomes gelatinous and translucent
occurs with NEBAL
Define pericarditis and give some causes
Inflammation of the pericardium
infectious, as an extension of pleuropneumonia
traumatic, i.e. from traumatic reticuloperitonitis
Define congestive heart failure
the end-point of a number of conditions.
for whatever reason, the heart compensatory mechanisms are exhausted, resulting in a decreased CO
What happens (generally) in congestive heart failure and how do we aim to treat this ?
the body becomes congested due to an inability of CO to match venous return
the RAAS system gets activated by low BP or BV, and aims to increase BP and BV. this adds to and worsens congestion
solution = diuretics (decrease venous return)
Define the problems with LEFT sided congestive heart failure
back up into the pulmonary system
lung congestion and oedema
lungs will be wet, heavy and non-collapsible
will see haemosiderin-laden macrophages (heart failure cells)
CS : dyspnoea with exercise, increased resp effort, cough, crackles on inspiration, froth in airways, syncope, weakness
Define the problems with RIGHT sided congestive heart failure
back up into the vena cava system
leading to increased systemic venous pressure and passive congestion
the big organs that are draining into the vena cava will have a back up of blood (splenomegaly, hepatomegaly and intestinal oedema)
Name the most common primary cardiac neoplasms
Hemangiosarcoma (right auricle and atrium)
Heart base tumours (most common in paraganglioma, neuroendocrine cell tumours)
Name the most common secondary heart neoplasms
Round cell neoplasms (most common)
lymphomas
Define thrombosis
coagulation as a pathology
Name the 3 components of Virchow’s triad
endothelial injury
hypercoagulability
abnormal blood flow
Name the gross and histo appearance of a chronic thrombus
onion-like appearance of layers built up over time
alternating layers of platelets, fibrin and RBCs +/- mineralization and fibrosis
Name the gross and histo appearance of an acute thrombus
dull red, more classic clot-like appearance
not that exiting on histo
Define fibrinoid necrosis
endothelial damage, characterized by accumulation of serum proteins and fibrin in the vessel wall
Define arteriosclerosis
“hardening of the arteries”
loss of artery elasticity
often insignificant but can promote thrombi due to blood flow disruptions
Define atherosclerosis
fibrofatty plaques (atheromas) in the wall of the vessel
Define an aneurysm
focal dilations of any vessel. tend to be idiopathic.
can be dissection, true or false
Define vasculitis
inflammatory cells within and around the wall of vessels with concurrent damage to the wall
name some common infectious aetiologies of vasculitis
EAV
orbiviruses
EIA
ASF
CSF
Rickettsia
Aspergillus
Heartworm
name some common non-infectious aetiologies of vasculitis
autoimmune or drug hypersensitivit
Define lymphoedema
defective transport OR abnormal vessel development OR blockage
leads to fibrosis, skin folds and ulceration
Define an intestinal lymphangiectasia
impaired protein absorption in the GI leads to protein losing enteropathy
Define lymphangitis
inflammation of lymph vessels
