atherosclerosis Flashcards
define hypertension
high blood pressure
aetiology of hypertension
genes
environment
characteristic of hypertension
140/90 BP
describe stage 1 treatment of hypertension
offer antihypertensive drug treatment to patients younger than 80
describe stage 2 treatment of hypertension
antihypertensive drug treatment
step 1 of treatment of hypertension for aged over 55
or black people of african/caribbean descent = calcium channel blocker or thiazide
step 1 of treatment of hypertension for aged under 55
ACE inhibitor or ARB
step 2 of treatment of hypertension
add thiazide type diuretic to step 1
step 3 of treatment of hypertension
add CCB, ACEi and diuretic together
step 4 of treatment of hypertension
resistant hypertension:
- unable to achieve target BP
strengths of antihypertensive therapy
help many people lower their high blood pressure and keep their hearts from becoming overworked.
weakness of antihypertensive therapy
- renal artery stenosis
- impaired renal function
- hyperkalaemia
treatment of hypertension during pregnancy
V hydralazine, labetalol and oral nifedipine
what is atherogenesis
formation of focal elevated lesions in intima of large and medium sized arteries
describe atherogenesis
Atheromas formalong the inside lining of your arteries and interrupt blood flow through your body
development of atheromatous plaques
- injury to endothelial lining of artery
- chronic inflammatory and healing response of vascular wall to agent causing injury
what characterises early atheromatous plaque
smooth yellow patches in intima
what characterises complicated atheroma
atheromatous plaque and haemorrhage into plaque
what characterises a fully developed atheromatous plaque
form at arterial branching points
risk factor of atheroma
hypercholesterolaemia
- lipids are involved in plaque formation and growth
what are the signs of hyperlipidaemia
- familial/primary vs acquired/secondary
- LDL, HDL, total cholesterol, triglycerides
- corneal arcus
- tendon xanothmata
- xanthelasmata
what is corneal arcus
white, blue or gray crescent shape (arc) made of lipid (fatty) deposits that curves around the outer edges of the cornea of the eye
what is tendon xanthomata
slowly enlarging subcutaneous nodules usually found attached to the Achilles tendon or tendons over the knuckles
what is xanthelasmata
a sharply demarcated yellowish deposit of cholesterol underneath the skin
describe ruptured atheromatous abdominal aortic aneurysm
media beneath atheromatous plaques gradually weakened - sudden rupture can cause massive haemorrhage
describe embolisation of distal arterial bed
detachment of small thrombus fragments from thrombosed atheromatous arteries
describe acute atherothrombotic occulsion
rupture of plaque can cause irreversible ischaemia and necrosis of tissues
what is thrombosis
the formation of a solid mass from the constituents of blood within the vascular system
pathogenesis of thrombosis
- atheromatous coronary artery
- turbulent blood flow
- loss of intimal cells
- collagen exposed
- platelets adhere
- RBC’s become trapped
- lines of Zahn
- propagation
- consequences
what are the factors causing thrombosis
- endothelial injury
- stasis or turbulent blood flow
- hypercoagulability of the blood
what is embolism
detached intravascular mass
factors causing embolism due to thrombus
mural thrombosis often associated with MI or left atrial dilation + AF)
factors causing embolism due to fat
after major fractures
factors causing embolism due to gas
decompression sickness - Na2 forms as bubbles which lodge in capillaries
factors causing embolism due to air embolus
head and neck wounds, surgery, CV lines
factors causing embolism due to trophoblast
pregnant women - lungs
define ischaemia
relative lack of blood supply to tissue/organ leading to inadequate O2 supply to meet the needs of the tissue/organ
describe hypoxic hypoxia
O2 level = low
inspired O2 = normal
PaO2 = low
describe anaemic hypoxia
inspired O2 = normal
blood = abnormal
describe stagnant hypoxia
inspired O2 = normal
O2 delivery = abnormal
describe cytotoxic hypoxia
inspired O2 = normal
tissue level = abnormal
describe cytotoxic hypoxia
inspired O2 = normal
tissue level = abnormal
what is infarction
ischaemic necrosis within a tissue/organ in living body produced by occlusion of either the arterial supply or venous drainage
relationship between atheroma and ischaemia
Most ischemic strokes are caused by atherosclerosis
describe biochemical consequences of ischaemia
reduced O2 leads to anaerobic metabolism which leads to cell death
describe the process of infarction
anaerobic metabolism leads to cell death leads to liberation of enzymes leads to breakdown of tissue
describe transmural infarction
ischaemic necrosis affects full thickness of the myocardium
describe subendocardial infarction
ischaemic necrosis mostly limited to a zone of myocardium under the endocardial lining of the heart
what is stable angina
a discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
what causes stable angina
reduction in coronary artery blood flow to the myocardium
non-modifiable risks of stable angina
Age, gender, creed, family history & genetic factors.
modifiable risks of stable angina
Smoking, Lifestyle- exercise & diet, Diabetes mellitus, Hypertension & Hyperlipidaemia
clinical presentation of stable angina
- Tar stains on fingers.
- Obesity (centripedal).
- Xanthalasma and corneal arcus (hypercholesterolaemia).
- Hypertension.
- Abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses.
- Diabetic retinopathy, hypertensive retinopathy on fundoscopy
what investigation should higher risk patients with suspected stable angina undergo
coronary angiography
what medicines are used for relief of stable angina symptoms
B blockers
Ca channel blockers
Lk channel blockers
all to achieve resting heart rate of under 60 BPM
medicines used to manage stable angina
statins, ace inhibitors and aspirin
what causes myocardial infarction
thrombotic occlusion of a coronary vessel caused by rupture of a vulnerable plaque
symptoms of myocardial infarction
- chest pain, which travels from left arm to neck,
- shortness of breath,
- sweating,
- nausea,
- vomiting,
abnormal heart beating
describe rate limiting drugs
for symptom relief
beta-adrenoreceptor antagonist
describe vasodilator drugs
for symptom relief
examples: nitrates, calcium channel blockers
describe sodium channel activator drugs
ranolazine
function of beta blockers
block the sympathetic system
example of beta blocker
bisoprolol
adverse effects of beta blockers
asthma, acute heart failure and bradycardia
benefits of beta blockers
reduces myocardial workload, reduces rate of ischaemic events and mortality
function of calcium channel blockers
Prevent calcium influx into myocytes and smooth muscle arteries/arterioles by blocking L-type Ca channel
examples of calcium channel blockers
amlodipine (DHP) verapamil (N-DHP)
function of vasodilators
Nitric Oxide mediated smooth muscle relaxation
examples of vasodilators
nitrates
describe the mechanism of action of thrombolytic therapy
- converting plasminogen to plasmin, an enzyme that breaks down fibrin, a protein that forms the backbone of blood clots.
- By breaking down fibrin, thrombolytics can dissolve blood clots and restore blood flow to the affected area
common complications of myocardial infarction
- ventricular septal defect (VSD),
- papillary muscle rupture or dysfunction,
- cardiac free wall rupture,
- ventricular aneurysm,
- dynamic left ventricular (LV)
- outflow tract (OT) obstruction
- right ventricular (RV) failure
what is the role of beta-blockers in angina
reducing myocardial oxygen demand by decreasing heart rate and myocardial contractility
what is the role of statins
preventing myocardial infarction = lowering cholesterol levels
what are the potential adverse drug reactions following treatment of ischaemic heart disease
bradycardia, dizziness, hypotension, hyperkalemia, cough, and renal impairment
what is stroke
neurological deficit of sudden onset due to a blocked (ischemic) or ruptured (hemorrhagic) blood vessel in the brain
causes of stroke
blockage with thrombus or clot, disease of vessel wall, disturbance of normal properties of blood, rupture
risk factors for stroke
- Age
- Hypertension
- Cardiac Disease (esp atrial fibrillation)
- Diabetes
- Smoking
- Family history
- Cholesterol
- Bleeding disorders
treatments for stroke
thrombolysis via atleplase
tissue plasminogen activator - within 3 hours of treatment
treatments for stroke
thrombolysis via atleplase
tissue plasminogen activator - within 3 hours of treatment
what is primary stroke prevention
Primary stroke prevention refers to the treatment of individuals with no history of stroke.
what is secondary prevention of stroke
- Secondary stroke prevention refers to the treatment of individuals who have already had a stroke or transient ischemic attack
- Measures may include the use of platelet antiaggregants, antihypertensives, statins, and lifestyle interventions
layers of thoracic aorta
tunica intima
tunica media
tunica adventitia
what is tunica intima
inner layer - endothelial
what is tunica media
middle layer - smooth muscle
what is tunica adventitia
outer layer - thin connective tissue
what is an aneurysm
localised enlargement of an artery caused by a weakening of the vessel wall
describe a true aneurysm
weakness and dilation of wall involving all 3 layers
describe a false aneurysm
rupture of wall of aorta contained by adventitia or soft tissue
clinical presentation of acute thoracic aneurysm
can be asymptomatic
- Shortness of breath (associated aortic regurgitation)
- Dysphagia and hoarseness
- Back pain
- Symptoms of dissection - sharp chest pain radiating to back (between shoulder blades), hypotension
- Pulsatile mass
what is aortic disection
tear in inner wall of aorta
presenting symptoms of acute aortic disection
- Chest pain – severe, sharp, radiating to back (inter-scapular)
- Collapse (tamponade, acute AR, external rupture)
- Stroke (involvement of carotid arteries)
examined symptoms of acute aortic dissection
- Reduced or absent peripheral pulses
- Hypertension or hypotension
- BP mismatch between sides
- Soft early diastolic murmur (aortic regurgitation)
- Pulmonary oedema
- Signs of CVA
what is coarctation
aortic narrowing close to where ductus arteriosus inserts
signs of coarctation
- Cold legs
- Poor leg pulses
what is marfans syndrome
an inherited disorder that affects connective tissue (fibrillin 1 gene)
what are possible aortic manifestations
- aortic/mitral valve prolapse - regurgitation
- aneurysm and dissection
- vascular - aneurysm, disection
clinical presentation of arterial occlusive disease
“six Ps”:
-pallor
- pain
- paresthesia
- paralysis
- pulselessness
- poikilothermia
clinical presentation of aneurysmal disease
abdominal or back pain with a pulsatile abdominal mass
what is carotid endarterectomy
surgical procedure to remove a build-up of fatty deposits (plaque), which cause narrowing of a carotid artery
benefits of carotid endarterectomy
- Reduces Risk of Additional Stroke
- Reduces Risk of First Time Stroke
- Safe Procedure
- The Procedure Has Durable Outcomes
complications of carotid endarterectomy
- surgical complications
- restenosis = plaque returning
- limited benefits for mild to moderate blockage
function of the venous system in the lower limbs
A system of muscular venous pumps and bicuspid valvesensure flow from superficial to deep and from caudal to cephalad within the lower extremity
what are the complications with venous incompetence
- Recruitment of veins
- DVT.
- Pulmonary embolism (PE)
- Venous ulceration.
- Secondary lymphedema.
symptoms of chronic venous insufficiency
- Swelling in your legs or ankles.
- Tight feeling in your calves or itchy, painful legs.
- Pain when walking that stops when you rest.
- Brown-colored skin, often near the ankles.
- Varicose veins.
- Leg ulcers that are sometimes hard to treat
clinical presentation of CLI
- Stage I: Asymptomatic, incomplete blood vessel obstruction
- Stage II: Mild claudication pain in limb
- Stage IIA: Claudication when walking a distance of greater than 200 meters
- Stage IIB: Claudication when walking a distance of less than 200 meters
- Stage III: Rest pain, mostly in the feet
- Stage IV: Necrosis and/or gangrene of the limb
clinical presentation of compartment syndrome
- Inflammation,
- oedema,
- venous obstruction
- tense, tender calf
what is balloon angioplasty
procedure in which your vascular surgeon inserts a balloon catheter into a narrowed portion of an artery to treat arterial occlusive disease
what is bypass grafting
surgical procedure to redirect blood flow around an area of blockage to treat arterial occlusive disease
