haemodynamic dysfunction Flashcards
define haemodynamic
factors that govern blood flow that are dependent on the relationship between cardiac output, blood pressure and resistance
cardiac out put = ?
heart rate X stroke volume
what is frank starling law
heart pumps more blood when its filled with more blood
more blood = stronger heart contraction = more blood out
what is oedema
accumulation of fluid in interstitial space
factors affecting intravascular and interstitial water movement
increased hydrostatic pressure
lymphatic obstruction
inflammation
decreased blood volume
when does fluid accumulate
if movement of water in tissues exceeds lymphatic drainage
what is hyperaemia
localised increased volume of oxygenated blood
an active process resulting from arteriole dilation
what does hyperaemia help with
removal of waste materials and dilution of harmful substances by bringing more fluid and antibodies to area
what is congestion
passive process resulting from impaired outflow from a tissue
2 types of congestion
systematic - cardiac failure
local - isolated venous obstruction
differences of hyperaemia and congestion
H = active C = passive
H = increased blood flow C = impaired blood flow
H during exercise/inflammation C venous obstruction and cardiac failure
H = oxygenated blood / redder C = de oxygnated / blue
what is left sided heart failure
chronic congestion of lung
aetiology of left sided heart failure
systematic HT
valve disease
primary myocardial disease
clinical presentation of L sided
pulmonary congestion
oedema
salt and water retention = coma
brown lung
what is right sided heart failure
caused by L sided
pulmonary congestion and raised arterial pressure
clinical presentation of right sided
congestion and oedema peripherally
effusions in pleura
ascites of peritoneum
splenomegaly - enlarged
what is haemostasis
blood clots at site of injury
what are platelets
helps with clot formation
activates clotting cascade
what is a haemorrhage
bleeding from a damaged blood vessel
six stages of clot formation
vasoconstriction
platelet
coagulation
formation of final clot
clot removal - normal blood flow
define thrombosis
blood clots at site of vascular injury
3 components of thrombosis
vascular wall
platelets
coagulation failure
what does Virchow’s triad say causes thrombus formation
endothelial injury
stasis of blood
blood hyper coagulability
what is the endothelium
thin layer of cells on the interior surface of blood, lymphatic vessels and heart
endothelial dysfunction is the key factor in which diseases
atherosclerosis
hypertension
diabetes- vascular complications
heart attack and stroke
what is propagation
additional platelets and fibrin accumulate
what is embolization
thrombi dislodges and travels through blood
what is an embolism
dislodged thrombi
what is ischaemic necrosis
death of tissue resulting from lack of blood supply
what is myocardial infarction
death of heart muscle due to blocked coronary arteries
what is hypoxemia
low level of oxygen in blood specifically arterial blood
what are most infarcts replaced by
scar tissue
