CV Flashcards
left vs right sided heart failure
right -
congestion of peripheral tissue - blood not flowing into the heart from them well enough
liver congestion - signs relating to impaired liver function
GI tract congestion - anorexia, GI distress, weight loss
oedema and ascites (modified transudate)
left -
decreased cardiac output
decreased tissue perfusion
pulmonary congestion - cough with frothy sputum, orthopnea (breathlessness lying down), nocturnal dyspnea
left failure –> right failure
chronic lung disease –> right failure
ventricular septal defect
hole in wall separating ventricles
common in cattle
left –> right shunt
pulmonary hypertension
atrial septal defect
hole in wall between atriums
left –> right shunt
right sided heart failure
ascites
pulmonic stenosis
narrowing of valve or artery from right ventricle to lungs
reduced flow to lungs
right sided heart failure
patent ductus arteriosus
failure of vessel between aorta and pulmonary artery to close
cuts out lungs
common in dogs
pulmonary hypertension, right sided heart failure
persistent right aortic arch
retained vessel
constricts oesophagus
tetralogy of fallot
combination - ventricular septal, pulmonary stenosis, overriding aorta and right ventricular hypertrophy (VPAH - very poorly animal heart)
mitral valve disease
small breeds - cavvys and sausages
regurgitation and systolic dystfunction (mitral valve closure)
dilated cardiomyopathy
large breeds - doberman and great dane
weak myocardium, big floppy heart, low cardiac output
right and left sided failure - left ventricle gets bigger filling and not pumping, back flow into atrium
chamber dilation and thinning of wall
ststolic failure
in cats - taurine deficiency in diet
arrhythmia
any abnormal rhythm
untreated can lead to cardiac failure or organ dysfunction
signs of cardiorespiratory disease
coughing
breathlessness
lethargy
exercise intolerence
murmur
collapse
weight loss
abdominal swelling/peripheral oedema
cardiac failure
cv system unable to provide enough flow for metabolic needs
usually gradual
signs -
related to poor cardiac output - weakness, hypothermia, depression
congestion - pulmonary effusion, ascites, pleural effusion
4 types -
systolic myocardial - general reduction in ability of heart muscle
obstruction - external compression or something in vasculature
pressure overload - long term increases in stress to heart wall
volume overload - increased volume of blood in ventricles –> congestive heart failure
cardiac output
volume of blood expelled per unit time
affected by -
hypertension
valvular heart disease
cardiomyopathy
heart failure
pulmonary disease
arrhythmia
fluid overload
decreased fluid volume
electrolyte imbalance
cardiac index
cardiac output over body surface area
preload
degree of ventricular stretch when blood supplied to heart
increased by -
increased central venous pressure
increased expansion of ventricles
increased force of atrial contraction
increased aortic pressure
reduced heart rate
pathology - valve stenosis
decreased by -
decreased venous blood pressure
impaired atrial contraction
increased heart rate
decreased ventricular afterload
ventricular diastolic failure
inflow valve stenosis
afterload
load the heart must eject against
related to aortic pressure
increased by -
aortic valve stenosis
heart failure
increased systemic vascular resistance
decreased by -
medications to promote vasodilation
end stage shock
tests for CVRS failure
blood pressure
radiography
lactate - lactate rises when anaerobic metabolism - sign of poor perfusion
acid base analysis - insufficient oxygen delivery from low blood oxygen (respiratory causes) or poor oxygen dlivery (cardiac causes) - more acidic
cardiac troponins - indicator of myocardial death (myocardial infarction)
NT-proBNP - differentiate between cardiac and respiratory causes of dyspnoea, released from cardiomyocytes when stretched
heartworm antigen - serology (antigen detectable 6 months after infection), modified knotts (performed at same time to catch false negatives)
hypertrophic cardiomyopathy
most common heart disease in cats
thickened ventricular walls - left ventricle can’t fully relax and fill
areas of fibrosis
enlarged left ventricle
thrombosis
blood flow back into atrium
gross appearance -
pulmonary oedema
pleural effusion
enlarged heart - over 20kg
left ventricle and intraventricular septum thickened
dilated left atrium
thromboembolism in aortic trifurcation
histology - fibrosis
stain with massons trichrome to see myocytes (red) and fibrosis (blue)
different from restrictive cardiomyopathy - fibrosis on endocardial surface instead of myocytes
Arrhythmogenic right ventricular cardiomyopathy
boxers
genetic - striatin production gene
syncope and sudden death with no previous signs noticed
arrhythmia
need section of right ventricle for pm diagnosis
mitral valve disease
ckc spaniels
murmur
degeneration of fibrous layer of mitral valve
left sided heart failure
may see left atrium bulge in radiography
endocarditis
microrganisms adhere to endocardium - proliferative lesions on valve surface
usually e coli, staph or strep - infection elsewhere, bacteria brought to heart in blood
endothelial death and thrombus formation
dirty IV catheter common cause in hospital
pericardial effusions
pericardial sac fills with fluid
dogs - ruptured hemangiosarcoma
sheep - clostridium perfingens D
Mulberry heart disease in pigs
vitamin E/selenium deficiency
ployphasic necrosis in heart and vasculature
mulberry look - multifocal red areas of myocardium
foot and mouth in pigs
heart necrosis
