Cardiovascular System Flashcards
what is cardiovascular disease?
diseases of the circulation
what are the main 4 types f CVD?
coronary heart disease
strokes and transient ishaemic attacks
peripheral atrerial disease
aortic disease
what are the types of coronary heart disease?
angina
myocardial infraction
heart failure
what is coronary heart disease?
when there is not enough oxygen to the heart (can be affected by atherosclerosis)
what is angina?
not enough oxygen in heart
what is myocardial infraction?
tissue death in the heart
what is the long term effect of heart failure?
death
what is the cause of transiet ishaemic attacks (TIA)?
arteries blocked
what i the cause of perpheral arterial disease?
arteries blocked in limbs
what is the cause of aortic disease?
aortic muscle gets bigger and bursts
what is epidemiology?
the study of health and disease in a defined population
what age and under should be seriously investigated when there is high blood pressure?
under 40 years old
what is primary prevention?
a strategy to identify and alter modifiable risks to reduce incidence in disease-free individuals or in the population
what is secondary prevention?
a strategy to target individuals with established disease, who have usually had an ‘event’ to reduce morbidity and mortality
what relationship in CV disease can we help and interupt from lifestyle and environment factors?
acquired vascular
what are the diseases that come under the vascular acquired CV disease?
HT
atherosclerosis
coronary disease
isch heart disease
AMI
stroke
what are the myocaardial congenital diseaases?
inherited CM
inheretid valce dis
structural abnormalities
inherited conduction defects
most CVDs are acquired, this means…
not inherited
most events due to lifestyle
influenced by non-modifiable risk factors
when should a formal risk assesment be carried out ?
where 10-year CVd risk i more than 10%
what steps should be taken in primary prevention?
lifestyle changes
offer support
tell risk measuremnet
offer medication
keep a record of changes
pharmacological intervention where necessary
what are the lifestyle factors that affect CVD?
smoking
overweight
diet and excercise
hypertesion
diabetes
hyperlipidaemia
what is the first line treatment for any/one with hypertension and type 2 diabetes
ACEi or ARB
what is the first line tratment for hypertenssion without type 2 diabetes aged under 55 and not african or afro-caribean?
ACEi or ARB
what is the first line tratment for hypertenssion without type 2 diabetes aged under 55?
CCB
what is the first line tratment for hypertenssion without type 2 diabetes and african or afro-caribean?
CCB
what is HbA1c?
measures the sugar levels in blood over the last 3 months
what is the pain and discofort in coronary heart disease made from?
when coronary arteries becomes narrowed by a build up of atheroma
narrowing is angina and if a blockage occurs it can cause a myocardial infraction
what is NSTEMI?
uncomplete blockage that will eventually block fully
what is a STEMI?
complete blockage
what is the secondary prevention of ACS, ischaemic stroke, TIA, peripheral artery disease?
antiplatelets
what is the secondary treatment for arrythmias?
anticoagulants
what is autoregulation?
normal resting conditions, redistributes blood as needed by tissues
what is the autoregulation process of low blod pressure?
stimulate endothelial cells to release endothelin and platelets are secreted this maakes the precapillary sphincters to vasoconstrict
what is the autoregulation of high blood pressure?
stimulate endothelial cells to release NO this causes vasodilation in the precapillary
what is neural regulation of blood pressure?
short term regulation of blood pressure, especially in responses to transient changes in arterial pressure, via baroreflex mechanisms
what type of nerves are vagus nerves?
parasympathetic which causes the heart to relax
if there is pressure in the aorta where is that signal received?
baroreceptors
if there is pressure on carotid sinus where is the signal recieved?
baroreceptors
what do the glossopharyngeal nerves connect?
carotid sinus to the brain
what do the vagus nerves connect?
aortic arch to the brain
what is the neural regulation of low blood pressure?
low BP –> aorta baro wide –> brain –> vagul nerve activation slower –> increase heart rate –> increase cardiac output –> BP raised
what is erythropeotin (EPO)?
EPO is a vasoconstrictor
that increases the blood viscosity, resistance and pressure
and decreases the blood flow
what does adrenaline/ nor-adrenaline do?
enhance and extend the bodys sympathetic activity
increases blood pressure
what does antidiuretic hormone do?
increase in tissue fluid osmolarity triggers ADH release
what is the neural regulation of high blood pressure?
increase in arterial blood pressure –> baroreceptors firing –> brain–> increase vagal activity –> low heart rate–> low cardiac output–> vasodilation–> low blood pressure
what is the hormonal regulation of high blood pressure?
no renin relase= no conversion= sodium excretion= lower osmotic pressure= reduction in vagus return= lower blood pressure
what does atrial natriuetic peptide do?
reduce renin= low blood volume= low blood pressure
what does angiotensin 2 do?
increases blood pressure
acts as a AT1 receptor
what is the receptor target for angiotensin 2?
AT1 (angiotenin 1 receptor)
what is the mechanisms of ACE inhibitors?
- arterial and venus vasodilation
- decrease blood volume
- downregulation of sympathetic activity
- suppression of hypertrophy (cardiac and vascular)
(reduces sodium and water reabsorption)
what are the typical names of ACEi?
prils
what type of drug is an ACEi?
pro-drug
this is an inactive drug that converts to active in the body/ the blood = in the body longer= works in the body longer and has a lasting effect
what are the adverse effects of ACEi?
dry, irritant cough
due to the accumulation of bradykinin (release of neurokining and substance P, this causes airway smooth muscle to constrict leading to bronchoconstriction and persistent dry cough. )
whar names are given to most ARBs?
sartan
what are ARBs?
ARBs are receptor antagonists that block type 1 angiotensin II (AT1) receptors on blood vessels and other tissues such as the heart.
what are the ADME of ARBs?
A; readily absorbed
d= binds to plasma protein
m= metaolised in the liver
e= eliminated through the kidney
what is the clinical consideration of ARBs?
Patients with bilateral renal artery stenosis may experience renal failure if ARBs are administered.
what is the name given to renin inhibitors?
aliskiren
what do renin inhibitirs do?
Renin-inhibitors produce vasodilation by inhibiting the activity of renin, which is responsible for stimulating angiotensin II formation.
what are the names given to calcium channel blockers?
dipine
what do calcium channels do?
L-type calcium channels located on the vascular smooth muscle, cardiac myocytes, and cardiac nodal tissue (SA and AV nodes) regulate the calcium influx and stimulate smooth muscle and cardiac myocyte contraction.
what do thiazide-like diuretics do?
inhibit active Na+ reabsorption and accompanying Cl- transport
what name is given to beta blockers?
lol
what type of heartbeat is a sign of AF?
irregularly irreglar
what heartbeat should be investigated?
weak heartbeat
what to do if in clinic the BP is higher than 140/90?
take another reading. if very different take another reading and record lower of 2nd or 3rd
what to do if BP is between 140/90 and 180/120?
offer ABPM or HBPM
what frequency does ABPM need to be recorded?
every 30 mins for 24 hours
how often does home bp monitoring need to be measured?
4 times a day for a week (only use last 6 days if its a first time use patient)
what stage of hypertension should be sent to the hospital?
stage 3
what is classed as stage 1 hypertension?
clinic blood pressure ranging from 140/90 to 159/99 and subsequent ABPM daytime average or HBPM average blood pressure ranging from 135/85 to 149/94
what is stage 2 hypertension?
clinic blood pressure of 160/100 or higher but less than 180/120 and ABPM/HBPM 150/95
what is stage 3 hypertension?
clinic systolic blood pressure of 180 or higher or clinic diastolic of 120 or higher
what else do we need to do when we investigate for high blood pressure?
assess for cardiovascular risk
assess for target organ damage
what assesments are in the tests for target organ damage?
blood in urine
protein in urine
measure of blood sugar over last 3 months (HbA1C)
ECG (left ventricle)
what should be presented to the patiemt when discussing their 10 year risk?
present individualised risk and benefit scenarios
present the absolute risk of events numerically
use apropiate diagrams and text
what are the modifiable risk factors?
smoking
cholestrol
blood pressure
BMI
what are the non-modifiable risk factors?
age
sex
FHx
migrane
RA
SLE
severe mental illness
what does anyone with hypertesion and diabetes recieve?
ACEi
what needs monitoring whilst on CCB?
BP not blood
what ACEi are you most likely to prescribe?
ramipril
what CCB are you most likely to prescribe?
amlodipine
what TLD are you most likely to prescribe?
indapamide
why is lipid modification essential for CVDs?
CVD is caused by blood clots or atherosclerosis, which is a build up of fat in the artery restricting blood flow
what is atherosclerosis?
is a condition where there is a build up of fatty deposists inside an artery which causes the artery to harden and narrow, restricting the blood flow
what is primary prevention?
strategies identify and alter modifiable risks to reduce incidence in disease-free individuals or in the population.
what is secondary prevention?
strategies target individuals with established disease, who have usually had an ‘event’, to reduce morbidity and mortality.
how is good cholestrol controlled?
by diet and lifestyle
how is bad cholestrol controlled?
can be treated
what percentage on the CVD risk should patients be prioritsed for an assessment?
10%
what should your HDL ratio be below?
5
when should pharmacological treatment be introduced to the patient?
after a discussion about the risks and benefits of treatment, co-morbidities, potential benefits from lifestyle interventions and the persons prefereance
if a patient presents with muscle pain from statins what should you do?
reduce dose
reassure them that a very small amount of people taking statins actually gain muscle pain
before starting lipid modification therapy, what should be tested?
a non-fasting lipid profile
liver function tests
renal function
HbA1c
creatinine kinase
thyroid stimulating hormone
for primary prevention of CVD what should be offered to patients?
atorvastatin 20 mg daily
for secondary prevention of CVD what should be offered to patients with exsiting CVD?
atorvastatin 80mg daily
what is familial hypercholesterolaemia (FH)?
an inherited conition characterized by high cholestrol concentrated in the blood
what are the potential developments of FH?
atherosclerosis andcoronary heart disease
what are some chlinica signs of hypercholesterolaemia?
tendon xanthomata (highly specific)
xanthelasmata (chlestrol deposits)(low specificity)
corneal arcus (white band before the coloured part of the eye)(highly specific)
what happens if Familial hyperlipidaemia is left untreated?
leads to greater than 50% risk of coronary heart disease in men by the age of 50 years and at least 30% in women by the age of 60
how to treat Familial hyperlipidaemia?
aggresive early treatment necessary as soon as diagnosed in adults?
in children with homozygous FH- lipid-modifying drug treatment is usually started by the age of 10 years or at the earliest opportunity thereafter, increase as they grow and aggressive treatment whenthey can tolerate it.
wht is the pharmacologicl treatment for hyperlipidaemia?
HMG-coA reductase inhibitors (statins)
what type of receptor is a AT! receptor?
G coupled receptor
what happens when AT1 is activated?
vasoconstriction and aldoterone release
the vasoconstriction increases peripheral resistance
the aldosterone release increases cardiac output
both of these increase blood pressure
what is pharmacokinetics?
the movement of drugs within the body, including absorption, distribution, metabolism and excretion
what enzyme system is responsible for metabolising many antihypertensive drugs?
cytochrome P450
when do additive interactions occur?
when the combination of two drugs produces an effect equal to the sum of their individual effects
when do synergistic interactions occur?
when the combination of drugs produces an effect greater than the sum of their individual effects
when do antagonistic interactions occur?
when the combination of drugs diminishes or cancels out their individual effects
what are teh ACEi drug-drug interactions?
Concurrent use of ACE inhibitors and nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce the effectiveness of ACE inhibitors and increase the risk of renal impairment, as NSAIDs can counteract the vasodilatory effects of ACE inhibitors.
what are ACEi drug-food interaction?
Consuming high-sodium meals or foods rich in potassium (such as bananas or oranges) can counteract the effects of ACE inhibitors by potentially increasing blood pressure or interfering with the balance of electrolytes.
what are ACEi drug-herbal interactions?
Taking St. John’s wort (Hypericum perforatum) along with ACE inhibitors may reduce the effectiveness of the medication due to St. John’s wort inducing DME that can accelerate the breakdown of ACE inhibitors.
what are CYP450 inducers?
Concurrent use of rifampin, an antibiotic and a potent cytochrome P450 inducer, with ACE inhibitors can accelerate the metabolism of ACE inhibitors, potentially reducing their effectiveness and requiring higher doses for adequate blood pressure control.
what are CYP450 repressors?
Concurrent use of fluoxetine, a selective serotonin reuptake inhibitor (SSRI) and a cytochrome P450 repressor, with ACE inhibitors can inhibit the metabolism of ACE inhibitors, potentially increasing their blood levels and leading to an increased risk of side effects.
what are ARB drug-drug interactions?
Co-administering beta-blockers with calcium channel blockers can lead to an enhanced blood pressure-lowering effect and an increased risk of bradycardia (low heart rate) due to additive negative chronotropic and negative inotropic effects.
what are ARB drug-food interactions?
Grapefruit juice may inhibit the metabolism of beta-blockers, leading to increased blood levels of the drugs. This can potentially intensify the effects of beta-blockers, resulting in prolonged heart rate reduction and lowered blood pressure.
what are ARB drug-herbal interactions?
Concurrent use of ginseng and beta-blockers may interfere with the blood pressure-lowering effects of beta-blockers. Ginseng can indirectly stimulate the production of adrenaline, which can counteract the beta-blocking activity of these medications.
what are CCB drug-drug interaction?
Simultaneous use of CCB and statin medications can increase the serum levels of statins, potentially leading to statin toxicity e.g. muscle pain and liver toxicity.
what are CCB drug-food interaction?
Consuming grapefruit can interfere with the metabolism of CCBs, leading to increased blood levels of CCBs. This interaction can enhance the hypotensive effects of CCBs.
what are CCB drug-herbal interactions?
Consuming hawthorn (Crataegus) alongside CCBs can cause additive effects on blood pressure reduction. Hawthorn has mild vasodilatory properties and can potentially enhance the antihypertensive effects of CCBs.
what are TLD drug-drug interactions?
Using thiazide diuretics in combination with NSAIDs can reduce the diuretic and antihypertensive effects of thiazides due to NSAIDs inhibiting renal blood flow and decreasing the efficacy of thiazid
what are TLD drug-food interactions?
Consuming licorice can lead to decreased potassium levels and increased blood pressure, counteracting the effects of thiazide diuretics.
This is due to licorice
- inhibiting the breakdown of cortisol, which can cause sodium and water retention
- decrease in potassium levels, as both can lead to potassium loss
what does AT1 do once activated?
vasoconstriction of the smooth muscles
aldosterone release
adrenergic innervations (adrenaline release and inhibit update)
antidiuretic release
what is ACE?
a zinc containing dipeptidyl carboxypeptidase enzyme
where is ACE located?
on the luminal side of the vascular endothelium
why is ACE found in the lungs as much?
the lung has a vast surface area of vascular endothelium, which is rich in ACE
what does ACE do?
cleaves the terminal histidyl-leucine from angiotensin 1 to form the ocapeptide angiotensin 2
what is angiotensin 2 ?
a peptide hormone, that acts at AT1 receptors, stimulating both vasoconstriction and aldosterone release
what does ACEi do?
ACE inhibitors lower blood pressure by reducing the vasoconstriction induced by angiotensin II, thereby decreasing peripheral resistance. Consequently, the lower Ang II level reduces the sodium and water reabsorption and cardiac output.
why do ACEi induce a dry cough in some patients?
ACEi blocks the breakdown of bradykinin, and increase bradykinin levels, which can contribute to the vasodiator action
accumulation of bradykinin induces sensitation of airway sensory nerves via rapidly adapting stretch receptors and C-fiber receptors that release neurokinin A and substance P
This causes airway smooth muscle to constrict leading to bronchoconstriction and persistent dry cough. (most common adverse effect, 10-20% of patients)
what should be monitored while on ACEi?
serum creatinine and potassium
assess renal structure and function (discontinue ACE inhibitors for patients with bilateral renal artery stenosis)
why are ACEi not reccomended for collagen vascular disease?
possible increased risk of agranulocytosis- blood counts recommended
what do ARBs do?
receptor agonists that block type 1 angiotensin 2 receptors on blood vessels and other tissues such as the heart
what are the possible adverse effects of ARBs?
hyperkalaemia
renal impairment
what is hyperkalaemia?
potassium retention
what caused hyperkalaemia from ARBs?
the reduction of aldosterone
what is renin?
proteolytic enzyme that catalyzes the conversion of angiotensinogen to angiotensin 1
what do renin-inhibitors do?
produce vasodilation by inhibiting the activity of renin, which is responsible for stimulating angiotensin 2 formation
what are the 2 classes of CCBs?
nondihydropyridines
dihydropyridines
what are dihydropyridines?
Dihydropyridine class of CCBs are highly vascular selective and reduce systemic vascular resistance and arterial pressure.
what is cholestrol?
27 carbon compound with a unique structure with a hydrocarbon tail, a central sterol nucleus made of four hydrocarbon rings, and a hydroxyl groups
what is the use of cholestrol?
essential component that makes the cell membrane and modulates membrane fluidity, and critical for cell growth and viability; Precursor for steroid hormones, vitamin D and bile salts
how is cholestrol absorbed?
absorbed from micelles into the intestinal wall through a recently identified protein channel , niemann-pick C1 like 1 protein on the enterocyte plasma membrane
what is the ‘‘de novo’’ synthesis?
the cholestrol synthesis in the liver?
are cholestrol and triglycerides insoluble in water?
yes
and they require a carrier protein
what are lipoproteins?
complex particles that mobilise cholestrol and Triglycerides
what are the functions of apolipoproteins?
- serving a structural role
- acting as ligands for lipoprotein receptors
- guiding the formation of lipoproteins
- serving as activators or inhibitors of enzymes involved in the metabolism of lipoproteins
what is the exogenous pathway of lipid homeostasis?
1.The exogenous lipoprotein pathway starts with the incorporation of dietary lipids into chylomicrons in the intestine.
2.In the circulation, the triglycerides (TG) carried in chylomicrons are metabolized in the muscle and adipose tissue by lipoprotein lipase (LPL) releasing free fatty acids (FA), which are subsequently metabolized by muscle and adipose tissue, and chylomicron remnants are formed.
3.Chylomicron remnants are then taken up by the liver.
what is the endogenous pathway for lipid homeostasis?
1.The endogenous lipoprotein pathway begins in the liver with the formation of VLDL
2.The triglycerides carried in VLDL are metabolized in the muscle and adipose tissue by lipoprotein lipase releasing free fatty acids and IDL are formed.
3.The IDL are further metabolized to LDL, which are taken up by the LDL receptor in numerous tissues including the liver, the predominant site of uptake.
what is the reverse cholestrol transport?
excess cholestrol from cells is brought back to the liver by HDL in a process known as reverse cholestrol transport
what are the steps in reverse cholestrol transport?
1.RCT begins with the formation of nascent HDL by the liver and intestine. These small HDL particles can then acquire cholesterol and phospholipids that are effluxed from cells, a process mediated by ABCA1 resulting in the formation of mature HDL.
2.Mature HDL can acquire additional cholesterol from cells via ABCG1, SR-B1, or passive diffusion.
3.The HDL then transports the cholesterol to the liver either directly by interacting with hepatic SR-B1 or indirectly by transferring the cholesterol to VLDL or LDL, a process facilitated by CETP.
what is the pathophysiology of atherosclerosis?
1) endothelial dysfunction
2) formation of lipid layer or fatty streak within the intima
3) migration of leukocytes and smooth muscle cells into the vessel wall
4) foam cell formation
5) degradation of extracellular matrix
what are the pharmacological options in lowering lipid?
- cholestrol syntheisi inhibition
- intestinal absorption
- lipoprotein lipase activity
- HDL
what is used for cholestrol synthesis inhibition?
statins
what is coronary artery from?
poor supply of oxygen to the heart
what are the conditions that lead to coronary artery disease?
hypertension
endothelial dysfunction
atherosclerosis
ischaemia
CAD
when will the heart recieve high oxygen?
relaxation (diastole)
why does relaxation still have high pressure in the aortic arch?
due to the backflow of the blood, also because the coronary artery is narrower therefore has higher pressure
what is the coronary circulation?
two tiny arteries leaving out the aorta
profuse blood to the myocardium
handles high pressure
how does coronary thrombosis develop?
thickening of the internal surface of arteries or progression of atherosclerotic lesions, occlude and affect oxygen supply to heart muscles