Cardio Vascular System Flashcards
what is stenosis
where only a small amount of blood can get through the valve = heart has to work really hard at a higher pressure = doesn’t open properly
what is incompetence
is where the valve doesn’t shut properly or has a hole in it = backflow = extra work for the heart
what are the three major causes of heart valve pathology
Rheumatic Fever
Calcific Aortic Valve disease
Age related disease
how does rheumatic fever cause heart problems
Low prevalence
Yellow swollen tonsils
Strep. Pyogenes
Body fights it off and cross reaction with self antigens
inflammation in myocardium and causes fibrosis in heart valves and ruffled, white, damaged
(90% mitral, 40% aortic)
what is calcific aortic valve disease
Calcium in the aortic valve appearing age related
Sometimes amplified where the valve is abnormal
Knobbly yellow lumps, very hard calcifications
Causes problems closing and opening causing stenosis and incompetence
why is aortic valve disease a problem for heart health
coronary arteries that supply the heart branch off just after the aortic arch
less blood can get through, heart has to pump harder and gets stronger = left ventricular hypertrophy
same amount of blood gets to coronary arteries so heart muscle gets tired
what is age relate valve disease likely to effect and how
Degrading mitral valve
Easily seen on a echo mycogram
Floppy mitral valve, very thin
how would we detect a weak mitral valve
mycogram
what types of artificial heat valves can be provided
Synthetic = ball and cage, tilting disc, synthetically grown forom pericardium
Biological = porcine, human
what tissue are heart valves made from
pericardium
what complications can we get from valve replacements
haemolysis
Coagulation - anticoagulation therapy needed with metal or plastic
mechanical failure - cage can break and ball can be released from ball and cage
calcification
infective endocarditis as rough surface is retentive for bacteria
Stitches too tight in sewed
rejection e.g. porcine
how might rheumatic fever lead to risk of endocarditis
rheumatic fever is a Strep. Pyogenes infection
Body fights it off and cross reaction with self antigens
causes inflammation and damage/fibrosis of heart valves
This roughens the surface of the valves and forms retention for bacteria that cause infective endocarditis
in what case might a patient be at risk of infective endocarditis with healthy heart valves and which valve might it effect
if the patient is an intravenous drug user
staph aureus can cause tricuspid valve infective endocarditis
what valve would be affected if a patient with healthy valves was to get infective endocarditis from IV drug use
Tricuspid
what are the local (2) and systemic (3) effects of infective endocarditis
Local:
Valve stenosis/incompetence
myocarditis infection of the myocardium heart muscle
Systemic:
general effects of illness
embolisms = organ infarcts, black rashes, splinter haemorrhages
glomerulonephritis (immune complex deposition)
how can infective endocarditis cause major organ infarcts (4)
infarct is death of tissue due to loss of blood supply
Valves form ‘vegetations’ - fibrin and bacteria and fragile valves
This can dislodge and form embolisms in major organs
this can cut off blood supply leading to death of parts of organs
give three micro-organism that can cause infective endocarditis and their route
risk of EC = Strep. Viridians from oral cavity through transient bacteraemia
healthy = IV drug user, Staph. Aureus
immunocompromised = natural fungus e.g. aspergillus
Strep pyogenes- rheumatic fever?
what percent of deaths does coronary heart disease cause
30% in men
what is another name for coronary artery disease
ischaemic heart disease
what are the three pre-disposing factors for vessel injury and atherosclerosis
Change in blood flow laminar → turbulent (high BP)
Change in vessel wall e.g. injury
Change in blood constituents e.g. too many platelets
Also high blood pressure, smoking, high cholesterol, obesity
what are the three causes of ischaemic heart disease
atherosclerosis, myocardial hypertrophy and small vessel disease
what are some risk factors for atherosclerotic plaque formation (4)
smoking
uncontrolled diabetes (controlled diabetes = no risk at all)
hyperlipidaemia
Hypertension
why might we get left ventricular hypertrophy? and what can this cause
This occurs if there are constricted vessels or faulty valves where the heart has to work harder to pump the same amount of blood. This strengthens the ventricles and leads to left ventricular hypertrophy and however the blood supply to the heart muscle itself does not increase meaning bigger muscle gets the same blood supply, making it more likely to fatigue
causes ischaemic heart disease
what causes small vessel disease and what can cause it
non obstructed blood vessels can still cause pain, down to arteriole level
Nitric oxide is a vasodilator so if nitric oxide is either underproduced or over destructed, this causes smooth muscle constriction
this can contribute to ischaemic heart disease