Lecture 7 - Vascular disease & Atherosclerosis Flashcards
What is the leading cause of death and disability in the world?
Cardiovascular disease
One person dies to CVD every __ minutes?
12
Which of these are not risk factors for CVD? Hypothyroidism Alcohol consumption Glucose intolerance/resistance Gender
Hypothyroidism
Is vascular disease present in all forms of CVD?
Yes
What is the earliest detectable risk factor for CVD?
Vascular disease
How can vascular disease be caused?
Damage, blockage or rupture of the vessel
Layers of Tunica Intima from superficial to deep. (blood vessel)
Internal elastic membrane
Lamina propria
Basement membrane
Endothelium
Layers of Tunica media from superficial to deep. (blood vessel)
External elastic membrane
Smooth muscle
Layers of Tunica externa from superficial to deep. (blood vessel)
Its literally just tunica adventitia
Examples of elastic arteries?
Aorta, major vessels
Which arteries/arterioles are considered pressure reservoirs?
Elastic arteries
Which arteries/arterioles expand and recoil?
Elastic arteries
Which arteries/arterioles are ‘conducting arteries’?
Elastic arteries
How many layers of muscle in muscular arteries?
25+ layers
Which arteries/arterioles are considered ‘distributing arteries’?
Muscular arteries
Which arteries/arterioles are capable of vasoconstriction/vasodilation?
Muscular arteries
Which arteries/arterioles are considered to be terminal
Arterioles
All the layers in a vein from superficial to deep
Tunica adventitia
Tunica media
Tunica intima (Internal elastic membrane -> Basement membrane ->endothelium)
What is a characteristic unique to veins and not arteries?
Valves
How many times more complaint are veins to arteries?
24x
Which vessels are considered capacitance vessels?
Veins
All vessels including the heart are lined with a singular layer of _____?
Endothelial cells
What is normal vascular function maintained by? (Chemical)
Nitric Oxide
Nitric Oxide has a quick or slow half life?
Quick
Nitric Oxide:
Reactivity?
More important in signalling or receiving messages?
Vasodilator or vasoconstrictor?
Free radical
Signalling
Vasodilator
Nitric oxide is produced endogenously by ___
Nitric oxide synthase enzymes
Which vessels undergo the most significant change, due to age?
Large elastic arteries
Changes occurring to arteries due to age:
a. ) hypo or hypertrophy? where?
b. ) smooth muscle change?
c. ) elastic change?
d. ) softening or hardening - why?
e. ) Chemical deposits?
– Hypertrophy of the tunica intima and tunica media
– Increase in smooth muscle and elastic tissues
– Elastic tissue forms concentric layers in the tunica intima
– becomes less elastic
– Collagen fibres start to replace smooth muscle tissue
– stiffening walls of vessel
– Calcium deposits in the tunica media
– Reduction in vessel elasticity & hardening of the vessel walls
Vascular dysfunction causes: Reduction in bioavailability and or bioactivity of NO (3 examples)
Degradation in NO
Decrease in NO activity
Decrease availability of NOs substrates and co-factors
Causes of vascular dysfunction due to damage of endothelium
– Turbulent blood flow
– Increased blood pressure
– Lifestyle factors – smoking, alcohol, excessive fats &/or sugars
– Inflammation & infection
Causes of alteration in epithelium
Inflammation – Increased vaso-tone – Increased thrombotic activity – Reduced dilation – Damaged endothelium
What is an aneurysm?
Excessive localised swelling in the wall of an artery
3 Consequences of vascular disease
Angina
Myocardial infarction
Heart failure
Definition of hypertension
Hypertension or elevated blood pressure is a sustained increase in the pressure exerted on vessel walls during the heart’s normal contraction and relaxation
What blood pressure would be considered hypertension?
> 140/90mmHg
What is Essential hypertension?
No specific medical cause to explain hypertension (90% of cases)
What is secondary hypertension?
Result from a specific underlying condition with a well-known mechanism
What is malignant hypertension
extremely high and uncontrolled hypertension
What is white-coat hypertension
Elevation in blood pressure due to seeing your GP
5 Causes of hypertension
- Single gene mutations – altered renal salt handling
- Autonomic nervous system – effect pressure, volume and chemoreceptor signals
- Renin-angiotensin-aldosterone system – Ang II, ADH and Aldosterone production which can affect Na+ & water reabsorption/secretion
- Vascular dysfunction – reduction in NO, thickening of vessel wall & impaired vessel response
- Lifestyle factors – overweight, excessive alcohol consumption, elevated glucose levels, high potassium and/or calcium levels
Symptoms of hypertension?
Very few symptoms, if pressure is very high headache and vision problems may occur
What long term damage and complications can occur due to hypertension?
– Increased work load on heart can lead to hypertrophy & heart failure
– Increase in blood flow & pressure can damage walls of vessels, leading to thrombus formation and/or ruptured vessel walls
– Increased blood flow to kidney affects workload & volume control
What are lifestyle treatments to hypertension?
Reducing weight, improving diet, increasing physical activity, quitting smoking
What are the categories of drug therapies for hypertension and what do they do?
- ACE inhibitors – prevent conversion of Ang I to Ang II
- Ang II receptor blockers – block the actions of Ang II
- Ca+2 channel blockers – block intracellular Ca+2 concentration increases
- Beta blockers – block stimulation of adrenergic receptors responsible for cardiac activity
- Diuretics – promote water loss
What are peripheral vascular diseases?
Circulation disorders that affect vessels outside the heart or brain.
Cause of peripheral vascular disease
Arteries or veins narrowing, blocking or spasming
What is claudication?
Pain in the body, most commonly the legs due to lack f blood supply, typically indicative of peripheral vascular disease.
What is the most common form of peripheral vascular disease?
Peripheral artery disease
Symptoms of peripheral vascular disease?
- Legs cramps and/or pain - exercise
- Numbness, tingling, coldness and/or ”pins & needles” – at rest
- Cuts or sores on lower legs or feet that don’t heal
- Necrosis of tissue
If peripheral vascular disease is left untreated, what can occur?
If left untreated, the damaged & hardened vessel wall can lead to a build
up of plaque and narrowing/complete occlusion of vessels
How is peripheral vascular disease diagnosed?
Diagnosis by ankle-brachial index = compares BP in your arm to the BP in your ankle
Treatment to peripheral vascular disease?
Lifestyle stuff: the classics, ya know, quit smoking, lose weight
Drug Therapy: BP drugs, Antiplatelet drugs, other blood thinners, monitor diabetes and/or cholesterol drug treatments
Serious case: balloon angioplasty, arterial bypass
What is arteriosclerosis?
Degenerative thickening of the arteries, making them less elastic
What is atherosclerosis?
Deposition of material in the vessel wall leading to plaque formation
Accumulation of lipid in the intima of the blood vessel =
atheroma
What does the formation of an atheroma in the bv lead to?
Formation of a plaque
What is a plaque comprised of?
Lesion comprised of lipid, connective and fibrotic tissue and cells including inflammatory cells.
What is the oxidative modification hypothesis?
The current oxidative modification or stress hypothesis of atherosclerosis predicts that LDL oxidation is an early, essential event in atherosclerosis and that Ox-LDL does contribute to both initiation and progression of atherosclerosis.
Progression of atherosclerosis? (6 steps)
Fatty Streak-> Foam cells -> Intermediate Lesion -> Atheroma -> Fibrous plaque -> Complicated lesion or rupture
In which layer of a blood vessel does atherosclerosis occur?
Deep to endothelial cells
A CANTOS study on atherosclerosis being an inflammatory disease showed selective targeting of inflammation through inhibition of ___ improves cardiovascular outcomes
IL-1beta
What two tests can be used to determine presence of atherosclerosis in blood vessels?
Ultrasound and angiography
Treatments of atherosclerosis?
– Angioplasty – insertion of a balloon to widen vessel walls
– Stents – plastic “vessel” to maintain vessel width
– Coronary artery bypass graft (CABG) – vessels are re-routed around the blockage
– Drugs to lower BP and cholesterol
– Nitroglycerin – dilates vessels
– Blood thinners, aspirin & anticoagulants
What is unstable angina?
Chest pain due to poor blood flow and oxygen to the heart. Without treatment can lead to heart attack
What causes angina?
Most cases = narrowing of the blood vessels supplying the heart
Is angina a disease or symptom?
Symptom of underlying heart problem
What is stable angina?
Pain in the chest due to increased workload of the heart. Usually disappears with rest (due to exercise)
Wha is an acute myocardial infarction?
Occurs when blood flow stops to a part of the heart and causes damage (infarction) o the heart muscle.
Where do myocardial infarctions occur?
Coronary arteries?
How are myocardial infarctions diagnosed?
ECG, Blood tests, chest X-rays, angiograms
What is cerebrovascular disease?
Vascular disease involving vessels of the brain
Difference between embolic stroke and thrombotic stroke? (Both types of ischaemic stroke)
Embolic = Clot forms elsewhere and lodges in the brain vessels Thrombotic = Clot forms in vessel within brain.
Difference between ischaemic stroke and haemorrhagic stroke?
Ischaemic = blockage in vessel Haemorrhagic = rupture of blood vessel or brain membrane
Causes of cerebrovascular disease
Ischaemic stroke caused by plaque build-up in vessel, narrowing or occluding the vessel and preventing blood flow. Plaque may rupture elsewhere and travel to brain. Haemorrhage stroke caused by high BP, weakening vessel wall -> rupture. Dementia and alzheirmers caused by protein build up in walls.
Symptoms of cardiovascular disease
- Difficulty walking
- Dizziness
- Loss of balance and coordination
- Difficulty speaking or understanding basic questions
- Numbness or paralysis in face, leg or arm – usually on one side of the body
- Blurred or darkened vision
- Sudden headache accompanied by nausea, vomiting or dizziness
Diagnosis of cerebrovascular disease
– Blood tests – clotting time, sugar levels or infection
– Angiogram – contrast dye x-ray of blood vessels
– Carotid ultrasound – determine blood flow to the brain
– CT scan or MRI
– Echocardiagram or electrocardiogram – imaging of heart and electrical signals of heart
Treatment of cerebrovascular disease
– Ischaemic stroke – remove the blockage via drugs or surgery
– Hemorrhagic stroke – drug to lower BP and possible surgery to repair the vessel
