cardiovascular risk problems Flashcards
what is the heart derived from
The heart is derived from visceral mesoderm. It comes from the cranial end of the embryo and starts as a hoarse shaped structure
the heart tube develops 5 dilations. what are they and what do they develop into in an adult heart
- truncus arteriosus = aorta, pulmonary trunk
- bulbus cordis = trabeculated part of the right ventricle, outflow part of both ventricles
- ventricle = trabeculated part of the left ventricle
- atrium = trabeculated part of both atria
- sinus venosus = sinus part R.atrium, coronary sinus
what day does the heart begin to loop and fold
day 23
in a foetus what do the aortic arches I,II,III,IV,V,VI develop into
I and II = mostly obliterated III = common carotid artery IV = right subclavian V = rudimentary or absent VI = sprout branches that form pulmonary aa
there are 3 parts to the embryonic venous system what are they
- vitelline- drain the yolk sac (venous structures relating to draining the gut)
- umbilical - from placenta
- systemic = the anterior cardinal veins that drain the head and neck and the posterior cardinal veins that drain the trunk
what are modifiable and non modifiable risk factors for cardiovascular disease
modifiable = smoking, diet, hypertension, diabetes mellitus, obesity, chromogenic factors, physical inactivity, alcohol consumption
non modifiable = personal history of CHD, family history , age, gender
what should be collected routinely and included in the clinical history for cardiovascular risk?
what should be measured when assessing cardiovascular risk?
- age, sex, lifetime smoking habit, Fox of cardiovascular disease, ethnicity
- blood pressure, weight and BMI, cholesterol, diabetes, rheumatoid arthritis
for cardiovascular disease what is the primary, secondary and tertiary prevention
- primary = reduce incidence in population
- secondary = detection and treatment of pre-symptomatic and early disease
- tertiary = reducing incidence/recurrences of chronic incapability among those with symptomatic disease
how clinically are you likely to come across lipids
- xanthomata (fatty growths develop under skin)
- xanthelasma ( yellowish deposit of cholesterol under skin ie eyelids)
- corneal arcus (cholesterol in the peripheral cornea)
- milky blood/serum
how do statins work
Statins fool liver enzymes into thinking they don’t have enough cholesterol by inhibiting an enzyme that’s involved in cholesterol syntheses in the cells (HMG coenzyme reductase). Expresses more LDL receptors on its surface ie increasing LDL clearance
what’s PCSK9s role in the LDL receptor pathway
- exerts control over LDL recycling pathway
- involved In the recycling of LDL receptors in cell
- acts as a brake - blocking PCSK9
- the more PCSK9 there is the more recycling possible
what are some lipid lowering drugs
- Statins
Pravastatin
Simvastatin
Atorvastatin - PCSK9 inhibitors
Alirocumab
Evolocumab - Fibrates
- Ezetimibe - only for patients who cannot tolerate statins
what are aetiologies of atheroma
- smoking
- hypertension
- hyperlipedemia
- diabeties
- older age
- male
- genetics
how does an atheroma form
- primary endothelial injury eg smoking, toxins ..
- accumulation of lipids and macrophages - increased LDL, reduced HDL. Induces pro inflammatory cytokines (V-CAM, IL-1 and TNF)
- migration of smooth muscle cells with growth factors present (PDGF, FGF, TGF alpha)
- increase in size - proliferation of smooth muscle with the formation of a layer of cells covering the extracellular lipid separates it from the adaptive smooth muscle thickening in endothelium
when does atheromatous narrowing of an artery likely to produce critical disease
- it is the only artery supplying an organ or tissue ie there is no collateral circulation
- the artery diameter is small (eg coronary artery vs common iliac artery)
- overall blood flow is reduced ie cardiac failure
what are some complications of atheroma
- stenosis = when a valve that is narrowed doesn’t open properly. The flaps of a valve may thicken, stiffen or fuse together
- thrombosis = formation of a blood clot inside a blood vessel of the heart
- aneurysm - bulge or swelling in the aorta
- dissection
- embolism - obstruction that travels from the heart to lodge in a blood vessel
what is arterial stenosis
The narrowing of the arterial lumen, reduced elasticity, reduced flow in systole, tissue ischaemia
what are clinical effects of cardiac ischaemia
reduced exercise tolerance, angina, unstable angina, myocardial infarction, cardiac failure
what os cardiac fibrosis
loss of cardiac myocytes, replacement by fibrous tissue, loss of contractility, reduced elasticity and filling
wha are superadded thrombosis and what can be the clinical effects
when plaques rupture thrombus forms over the top and can completely block the arterial lumen in a coronary artery
clinical effects:
- MI
- Cerebral infarction
- Renal infarction
- Intestinal infarction
how is an aneurysm formed and what are the complications
- abnormal and persistent dilation of an artery due to a weakness in the wall
- mycotic, atherosclerotic, dissecting, congenital, arteriovenous, traumatic
- commonest site = abdominal aorta
complications = rupture, thrombosis, embolism, pressure erosion of adjacent structures, infection
what is arterial dissection
- splitting within the media by flowing blood
- false lumen filled with blood within the media
- sudden collapse and high mortality
what is an embolism
- both superadded thrombus and plaque material may break off and embolism
what is essential hypertension
defined as the rise in blood pressure of unknown cause that increases risk for cerebral, cardiac and renal events. blood pressure is greater than 140/90 mmHg. “the level of BP where treatment does more good than harm”
