Dysfunctions of the cardiovascular system

1
Dysfunctions of the cardiovascular system
2
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

3
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

4
Dysfunction of the cardiovascular system

• There are 3 main dysfunctions of the
  cardiovascular system
• Change in blood pressure
• Coronary artery disease
• Heart attack

5
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.

6
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)

7
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
• Headache
• Sleepiness
• Confusion
• Coma

8
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

9
Questions on coronary artery disease

• What is the CONDITION coronary artery 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?

10
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

11
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

12
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

13
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

14
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 dont

15
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.

16
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

17
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

18
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

19
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

20
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

21
Coronary artery disease (CAD)
22
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
• 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

23
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!

24
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

25
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)

26
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

27
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

28
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

29
Heart attack

• Heart transplant procedure
• A donor heart must be found this must be from
  an 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

30
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.

31
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.

32
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.

33
Pacemaker
34
Detailed treatments for CAD

• 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.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.