LO's vascular conditions Flashcards
Describe arteriosclerosis
- it is the thickening and hardening of the walls of the arteries.
- it occurs due to the migration of smooth muscle cells and collagen fibers into the tunica intima
- this narrows the lumen of the artery
Outline the pathophysiology of atherosclerosis, including risk factors and associated complications
- the most common type of arteriosclerosis
- The build-up of fats, cholesterol and other substances in and on the artery walls which hardens over time, causing obstruction of blood flow
risk factors are - family history
- increasing age
- smoking
-hypercholesterolaemia - hypertension
- diabetes
- obesity
- physical inactivity
complications: - angina pectoris and myocardial infarction
- transiet ischemic attack and stroke
- aneurysm
- peripheral artery disease
- gangrene
Distinguish between LDL and HDL cholesterol and outline the healthy ranges for cholesterol & lipids in blood
LDL (bad cholesterol)
- low-density lipids
- transport cholesterol to body tissues
- they are pro-atherogenic because they readily move through blood vessel walls where they can be oxidized
HDL (good cholesterol)
- high-density lipids
- transport cholesterol back to the liver
- anti-atherogenic as they increase transport of cholesterol away from tissues back to the liver
LDL cholesterol- less that 2.0mmol/L
HDL- more than 1.0 mmol/L
total cholesterol- less than 4.0 mmol/L
triglycerides- less than 1.7 mmol/L
Describe the pathophysiology of peripheral artery disease, including signs & symptoms
- A circulatory condition in which narrowed blood vessels reduce blood flow to the limbs
- caused by atherosclerosis within arteries of the limbs especially lower limbs
- associated with diabetes and coronary artery disease and has the same risk factors as atherosclerosis
signs and symptoms
- intermittent claudication; pain/ cramping in the lower limbs when moving or exercising
- changes in skin colour of lower limbs
- leg ulcers
- weak or undetectable pulse in legs or feet
- severe pain with acute occlusion
- gangrene
Describe the pathophysiology of deep vein thrombosis (DVT), including risk factors and signs & symptoms
- thrombosis is a formation of a blood clot within blood vessels, most commonly veins
- the thrombus partially or completely occludes the lumen of the vessel- in arteries this can cause tissue ischemia and in veins can cause localised inflammation
- deep vein thrombosis is when thrombosis occurs in the deep veins of the limbs, generally the lower limbs
- they carry the risk of becoming dislodged and forming an embolus (collection of matter circulating within the blood stream)
the three things that promote deep vein thrombosis are
- endothelial injury
- blood stasis
- hyper coagulability (increased coagulation activity)
risk factors
- surgery
- immobilisation
- obesity
- dehydration
- smoking
- coagulopathies
- pregnancy
signs and symptoms
- inflammation (warmth, redness, swelling, pain)
- oedema in affected limb
preventative measures
- hydration
- early mobilisation
- avoid standing or sitting for long periods of time
- use compression stockings when mobility will be reduced for a period of time
- some anticoagulants
Outline the pathophysiology of pulmonary embolism, especially as it relates to DVT
- an embolism occurs when an embolus gets stuck in an artery it is to small to pass through, stopping blood flow.
there are 2 types
systemic/ arterial embolism;
an embolus originating within the left side of the heart or a larger systemic artery gets stuck in a smaller systemic artery
common locations are
- arteries of the lower limb, leading to arterial insufficiency and tissue ischemia
- coronary arteries, leading to myocardial infarction
- cerebral arteries, leading to TIA or stroke
pulmonary embolism
- occurs when an embolus originating from within the right side of the heart or the systemic venous gets stuck in a pulmonary artery, the most common cause is a dislodged DVT
the dislodged DVT travels through larger and larger veins into the right hand side of the heart where it is pumped into the pulmonary trunk and arteries, then the embolus passes through smaller and smaller pulmonary arteries until it gets stuck in one. this can lead to infarction and be life threatening depending how much blood flow it is stopping
the pathophysiology of atherosclerosis
when there are large amounts of LDLs in the blood, macrophages release chemicals that oxidize the LDLs and then they ingest them and become foam cells. the foam cells come together and they form a fatty streak on the wall of the artery, this promotes changes in the connective tissue and muscle layers of the wall. smooth muscle cells start to migrate into the endothelial layers and there is increased collagen production which covers up the fatty streal and smooth muscle cells which becomes plaque. this hardens and thickens the arterial wall and narrows the arterial wall
- plaques are susceptible to rupture and if they rupture it forms a blood clot which further restricts the artery
signs and symptoms and risks of a pulmonary embolism
signs and symptoms
- chest pain
- sudden cough
- coughing up blood or bloody mucus
- increased respiratory rate
- shock
- collapse
- increased or erratic heart rate
- shortness of breath
risks that can lead to respiratory or cardiac failure and death
- pulmonary hypoxia
- vasoconstriction
- pulmonary hypertension
- oedema
- alterations in normal cardiac function
