Transcript Presentation: Dysfunctions of the cardiovascular system

DYSFUNCTIONS OF THE
CARDIOVASCULAR SYSTEM
Learning objectives
 To know the consequences of having faulty
heart valves
 To know that coronary artery disease, heat
attacks and changes in blood pressure are
dysfunctions of the cardiovascular system
 To know the treatment and diagnosis for
coronary artery disease, heart attack and a
change in blood pressure
Faulty valves
 Occasionally, valves on the heart do not function
properly
 This causes several effects of the body:
 backflow of blood occurring:
 If this occurs between the right ventricle and pulmonary
artery then not enough blood gets to the lungs so cant
get oxygen
 If this occurs between the left ventricle and aorta then
not enough oxygenated blood gets to cells
 Poor pressure for pumping blood
 Fainting/collapsing
 Cold hands and feet
 Low blood pressure
Dysfunction of the
cardiovascular system
 There are 3 main dysfunctions of the
cardiovascular system:
 Change in blood pressure
 Coronary artery disease
 Heart attack
Changes in Blood Pressure
 Condition:
 Blood pressure is the force exerted by the blood on the walls
of the blood vessels
 High blood pressure is called HYPERTENSION and this is
when the blood pressure significantly greater than the
average blood pressure
 Average : 120 / 80 mm/Hg (millimetres of mercury)
 Said as 120 over 80
 High blood pressure: 140 / 90 mm/Hg
 The top (first) number is the systolic pressure. This is the
pressure in the arteries when the heart contracts.
 The bottom (second) number is the diastolic pressure. This is
the pressure in the arteries when the heart rests between each
heartbeat.
Changes in Blood Pressure
 Condition:
 Blood pressure naturally decreases as the blood vessel get
smaller
 E.g. The highest blood pressure is found in the arteries and the
lowest in the veins (capillaries are variable)
Changes in Blood Pressure
 Causes:
 Genetic predisposition (family history of high blood pressure)
 Lifestyle:
 Smoking
 Alcohol
 Diet
 Stress
 Symptoms: rarely causes symptoms
 Severe hypertension can cause:
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Headache
Sleepiness
Confusion
Coma
Changes in blood pressure
 Diagnosis:
 Blood pressure monitor – checking of the blood
pressure regularly
 Treatment:
 Lifestyle changes:
 not smoking
 drinking less
 avoiding fatty foods
 Avoiding foods with lots of salt in
 Drugs to:
 lower blood pressure if it is 140/90 mmHg or higher.
 lower your cholesterol level
Questions on coronary artery
disease
 What is the CONDITION coronary artery
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disease?
List the CAUSES of coronary artery disease
What are the SYMPTOMS?
How can it be DIAGNOSED?
What TREATMENTS are available?
What are the RISK FACTORS?
Coronary artery disease
 Condition:
 A blockage or narrowing of coronary arteries (the
arteries that supply the heart with oxygen and glucose)
 This leads to the heart muscle not receiving enough
oxygen and a build up of carbon dioxide so it cant
respond to exercise demands
Coronary artery disease
 Causes: the blockages can occur due to several
reasons:
 Genetic predisposition (family history of high blood
pressure)
 Lifestyle:
 Diet
 Fat/cholesterol deposits in the arteries from fatty food which
reduces the size of the lumen (space inside the artery)
 This restricts blood flow therefore blood pressure is increased.
 This is known as atherosclerosis.
 Smoking – increases blood pressure and fat deposits
 Alcohol – excessive intake increases blood pressure
 Stress – puts strain on heart making it beat quicker
Coronary artery disease
 Causes: the blockages can occur due to several
reasons:
 Age:
 fat/cholesterol builds up due to years of eating
 arteries lose collagen and elasticity causing walls to become rigid
and preventing blood from flowing smoothly.
 This increases blood pressure
Coronary artery disease (CAD)
 Symptoms
 Chest pain called angina:
 dull ache or pressure spreading to the arms
(especially left arm), neck, or back due to blood
being force through blockage/narrow part of artery
 brought on by exertion e.g. Walking briskly
 Shortness of breath
 Indigestion
 Can be symptomless
Coronary artery disease (CAD)
 Diagnosis:
 By diagnostic imaging so that the heart and blood
vessels can be seen
 Chest X rays – outline of structure can be seen and
changes detected
 Coronary angiography
 patient injected with an opaque medium into the blood
 This shows up on X rays so that blood flow can be seen
 Better than just x rays as shows soft tissues which normal x
rays don’t
Coronary artery disease (CAD)
 Diagnosis:
 MRI scan: magnetic resonance imaging
 scan of the heart producing high quality images
 Is used to assess the progress of coronary artery bypass
graft
 May eventually replace or coronary angiography
 The patient lies inside a large, cylinder-shaped magnet.
 Radio waves are sent through the body. This makes nuclei
in the body's atoms move
 As they move back into place they send out radio waves of
their own.
 The scanner picks up these signals and a computer turns
them into a picture.
Coronary artery disease (CAD)
 Diagnosis:
 CT scan:
 CT= computer tomography
 Take images of a heart beat
 Good but a long waiting list to have the scan
Coronary artery disease (CAD)
 Diagnosis: ECG – electrocardiogram
 ECG shows the electrical activity of the heart so it shows
the pathway starting from atria - SAN, bundle of His,
purkinje fibres and finishing at ventricles contracting etc
 The electrical impulses are recorded on a piece of paper
 A typical trace shows:
 P wave - atria contracting
 QRS complex - ventricles contracting
 T wave – ventricles relaxing
Coronary artery disease (CAD)
 Diagnosis: ECG – electrocardiogram
 Can show lots of different things:
 Irregular heat beat rhythm – faster (tachycardia) or slower
(bradycardia) than normal
 Bigger or smaller time intervals in between waves can
indicate heart abnormalities
 Can show where a ‘misfire’ occurs
 Problems with the chambers
 Problems with thickening of the ventricle muscle or other
heart muscle disorders
Coronary artery disease (CAD)
 Diagnosis: Coronary Catheterization (angiogram)
 Under local anaesthetic, a small cut is made in a
artery to the heart
 A liquid dye is injected into the arteries of the heart
through a long, thin, flexible tube (catheter) that is
threaded through an artery.
 The arteries then become visible on X-ray and
videotape, showing areas where coronary arteries
may be blocked.
 The catheter may also be used to push open a
blocked artery, a procedure called an angioplasty
Coronary artery disease (CAD)
 Treatment
 Coronary artery bypass graft (CABG) = heart bypass
 Restores normal function by providing a new route for
blood to flow to the heart bypassing the blocked coronary
artery
 Procedure:
 Cut a length of vein usually from the leg
 Cut at the one end of the blocked coronary artery so that
there is a ‘blockage free’ end
 Attach one end of the new vein to the cut end to the
‘blockage free’ end of the coronary artery
 Attach the other end of the new vein to the artery allowing
blood to flow freely
Coronary artery disease (CAD)
Coronary artery disease (CAD)
 Treatment: CABG
 Can sort out more than one blockage and attach more
veins e.g. Double heart bypass, triple heart bypass
 Advantages
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Oxygen can get to all parts of heart
Heart beat is stronger
Pain and angina goes away
Live longer
 Disadvantages
 Danger of heart surgery as the patient has to be placed on a
heart lung machine
 Full function cannot be replaced
 The graft can rupture – burst open and cause internal
bleeding and death
Coronary artery disease (CAD)
 Treatment
 Lifestyle changes:
 Healthier diet
 avoid fatty foods especially saturated (animal) fat to
prevent fat depositing in the coronary arteries and
prevention of obesity
 Avoid foods with high levels of salt
 Stop smoking to try to decrease blood pressure and
prevent more fat deposits
 Limit alcohol intake to help with reducing blood
pressure
 Avoid stress!
Coronary artery disease (CAD)
 Risk factors for CAD
 Being male
 Family history
 Smoking
 High alcohol intake
 High levels of fat in the diet
 High blood pressure
 Obesity
 Inactivity
Heart attack
 Condition:
 Heart attack and myocardial infarction are essentially
the same
 It is when the heart muscle dies and so cannot beat
any longer
 This means that blood cannot be pumped around the
body
 Causes:
 Occurs due to a blockage in the coronary arteries:
 Coronary artery disease
 Coronary thrombosis (blood clot in the coronary artery)
Heart attack
 Symptoms
 Uncomfortable pressure causing chest pain
 Pain spreading to the shoulders, neck or arms
especially left arm
 Light headedness, fainting, sweating, nausea or
shortness of breath.
 Anxiety, nervousness and/or cold, sweaty skin.
Paleness or pallor.
 Increased or irregular heart rate.
 Diagnosis
 Any technique that diagnoses CAD
Heart attack
 Treatment
 If a major coronary artery is affected then often
the patient dies so there is no treatment
 However, if it is not a major coronary artery then
the patient can be treated and live
 Can treat a heart attack by removing the blockage
so same treatments as CAD often work
Heart attack
 Treatment: heart transplant
 If a major part of the heart muscle has died or
is not functioning properly then the only
option would be to replace it
 Donor = is the person who has donated the
heart (dead!)
 Recipient = is the person who is receiving the
heart
So the donor heart is put into the recipient
Heart attack
 Heart transplant procedure:
 A donor heart must be found – this must be from an
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individual who has been pronounced dead
The donor heart must be kept chilled in saline
The recipient of the heart has to be tissue-typed to see
if the heart is compatible with them
The chest is opened and the patient is placed on a
heart lung machine as most of diseased heart is taken
out but all major blood vessels are left intact
The new heart is put in and attached to the major
blood vessels
The patient must be put on immunosuppressant drugs
to stop the body rejecting the new heart which means
that they are susceptible to infection
Heart attack
 Heart transplant – prevention of rejection:
 The patient must be put on immunosuppressant
drugs to stop the body rejecting the new heart
 People on immunosuppressant drugs are susceptible
to infection as it is stopping the immune system from
working properly
 If they did not have these drugs then the body would
see the new heart as ‘foreign’ and attack and destroy
it.
Other Heart Treatments
 There are other treatments that can be used
for other heart disorders such as misfiring of
the heart – irregular heart beats e.g. having a
pacemaker fitted.
Heart pacemaker
 If the SA node does not function correctly then the
heart cannot pump blood efficiently.
 The SA node is a pacemaker meaning that it sets the
pace of the heart beat and allows it to maintain its
rhythm
 If this is not functioning correctly then an artificial
pacemaker can be fitted
 To do this, an insulated wire is put into a major vein
with an electrode in the heart muscle itself
 The battery end is located just under the skin e.g.. in
abdomen or collar bone
 Batteries can easily be replaced as easy to get to.
Pacemaker
Detailed treatments for CAD
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Cholesterol-lowering medications. By decreasing the amount of cholesterol in the blood,
especially LDL (the "bad" form of cholesterol), these drugs decrease the primary material that
deposits on the coronary arteries. Examples include statins, niacin, fibrates and bile acid
sequestrants.
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Aspirin. This common over-the-counter medication may be recommended as an anti-platelet,
which thins the blood, and as an anti-coagulant, which reduces the tendency for blood to clot and
block a coronary artery, causing a heart attack. Other anti-platelet drugs or anti-coagulants may
be prescribed as well.
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Beta-blockers. These drugs help make the heart's job of pumping blood easier by relaxing the
heart, slowing its rhythm, decreasing blood pressure and lowering the heart's demand for oxygen.
They include metoprolol, atenolol and propranolol.
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Nitroglycerin. This drug, as a tablet, spray or skin patch, helps relieve chest pain (angina) by
opening narrowed blood vessels and improving blood flow to the heart muscle. The patient may
also receive nitrates, a longer-lasting form of nitroglycerin.
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Calcium channel blockers. These medications help to open coronary arteries to increase blood
flow to the heart muscle. They can also help reduce high blood pressure.
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ACE inhibitors (angiotensin converting enzyme inhibitors). Similar to beta-blockers, these help
lower blood pressure and make the heart's job of pumping blood easier. In addition, ACE inhibitors
have shown significant benefits for patients in recovering from a heart attack. They include
ramipril, lisinopril, enalapril and captopril.
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Vitamins. Folic acid, B-6 and B-12 are vitamins that help to decrease homocysteine in the blood.
Homocystiene has been associated with accelerated clogging of the arteries (atherosclerosis). In
specific situations, some patients may be prescribed L-arginine or Omega-3 fatty acids.