Cardiovascular Diseases

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Cardiovascular Diseases

• By
• Prof. Fathi El-Gamal
• MB Ch B, M Sc, PhD (England)

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Introduction

• Cardiovascular disease (CVD) or diseases of the
  circulatory system can be described as
• All diseases relating to the heart and blood
  vessels .

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The main conditions include

• Coronary heart disease,
• Cerebro-vascular disease,
• Hypertension
• diseases of the pulmonary circulation,
• peripheral vascular disease,
• diseases of the arteries, veins, lymphatics,
• rheumatic disease
• and other circulatory conditions.

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Introduction

• Cardiovascular disease is a high priority health
  issue in the community. Why?
• A large proportion of those
• dying or
• utilizing both acute and other health care
  support and services
• are in fact suffering from
• - various cardiovascular diseases
  or
• - co-morbidities associated with
• cardiovascular diseases

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Introduction

• Lifestyles are often affected by it, resulting in
  disability and/or deterioration in quality of
  life.
• Cardiovascular disease accounted for 40 per cent
  of all deaths in develped countries, and 22 per
  cent of years of potential life lost.

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Heart diseases are leading cause of death in
developed countries
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Social and financial cost

• Major issues related to cardiovascular disease
  include the considerable social and financial
  costs associated with it.
• This implies that, if cardiovascular disease
  could be eliminated
• huge amounts of current disability would also be
  eliminated
• and people could enjoy healthy lives to a greater
  extent.

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CARDIOVASCULAR DISEASE

• At any given time, the distribution of blood in a
  person's body will be approximately
• 64 veins,
• 13 arteries,
• 9 pulmonary vessels,
• 7 heart and
• 7 arterioles capillaries.

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• Although the heart weighs less than 1 of the
  total body weight, it relentlessly receives
  nearly 5 of the total blood flow
• (which may explain why the arteries of the
  heart can so easily develop problems).

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Common conditions associated with CVD

• Congenital defects and infectious disease can
  strike any-where,
• but by far the most common disease occurs in the
  arteries
• atherosclerosis.

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• Blockages
• can occur in veins as well as in arteries, but
  these tend to be caused by blood clots (thrombi)
  rather than by atherosclerosis.
• Thrombophlebitis
• (often simply called phlebitis) most commonly
  involves clotting of blood and inflammation of a
  vein in the leg.
• This can be serious if a portion of the clot
  becomes detached, travels through the heart, and
  gets pumped to the lung where it blocks a
  pulmonary artery as a pulmonary embolism.
• About 10 of people with pulmonary embolism die
  within an hour.

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• Clotting of blood in the veins can occur when
  blood flow is slow or stagnant.
• This can occur during long periods of
  immobilization such as
• when confined to a hospital bed,
• cramped in a crowded airplane on a long flight
• or driving for an extended period.

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ATHEROSCLEROSIS

• Arteriosclerosis (hardening of the arteries)
• occurs "naturally" with aging as a result of
  cross-linking of macromolecules like proteins and
  polysaccharides.
• Atherosclerosis
• refers to the formation and hardening of fatty
  plaques (atheromas) on the inner surface of the
  arteries.
• In atherosclerosis, the arteries not only harden,
  they narrow, sometimes narrowing so much that
  hardly any blood can get through.
• Such narrowed vessels are easily blocked by
• constriction or
• objects in the bloodstream

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• The internal surface of an artery is covered with
  a single layer of endothelial cells that are
  pressed against each other like flagstones on a
  terrace.
• Atherosclerosis begins with injury to
  endothelial cells, exposing portions of the
  artery surface below the endothelium.

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• Injury to the endothelium
• Free radicals,
• chemicals in cigarette smoke
• or other irritants could be responsible for the
  injury,
• as could turbulence and mechanical force due to
  high blood pressure.
• Platelets clump around the injured endothelial
  cells and release prostaglandins, which cause the
  endothelial cells to proliferate like cancer.
• LDL-cholesterol particles release their fat into
  the areas made porous by prostaglandins.

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• Macrophages (scavenger white blood cells) engorge
  themselves on oxidized LDL-cholesterol until they
  become unrecognizable "foam cells" that invade
  atheromas.
• Then the atheromas are hardened by fibrin (which
  forms scar tissue) and finally by calcium
  patches.
• A vicious circle often arises with scar tissue
  attracting more platelets and LDL-engorged
  macrophages.

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ATHEROSCLEROTIC CARDIOVASCULAR DISEASE

• Atherosclerosis can occur in any artery.
• Most commonly it occurs in the aorta, the artery
  that receives blood directly from the heart.
• Since the aorta is the largest artery in the
  body, it is rarely critically narrowed by
  atheromas.
• Nonetheless, atherosclerosis can contribute to
  aneurysms (responsible for only one-fortieth the
  mortality rate of heart attack)

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• The most frequent life-threatening problems,
  however, are caused by the arteries supplying
• the heart,
• the brain
• and the kidneys, in that order.
• An estimated 70 of North Americans have coronary
  atherosclerosis (narrowing of the arteries of the
  heart), although the overt symptoms may not be
  evident until the arteries are three-quarters
  occluded.

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• Coronary artery atherosclerosis leads to
• angina pectoris,
• heart attack
• and cardiac arrest.
• Brain artery atherosclerosis leads to
• transient ischemic attack (TIA)
• and stroke.

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Angina pectoris (Latin "strangling in the
chest")

• The coronary vessels narrow temporarily causing
  the heart muscle to suffer ischemia (lack of
  oxygen).
• This is often accompanied by symptoms of
• crushing,
• diffuse pain in the chest (directly over the
  heart),
• a shortness of breath (air hunger) that leads to
  gasping,
• weakness,
• anxiety,
• light-headedness (faintness ,dizziness )
• nausea
• and sweating..

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Myocardial infarction (Heart attack)

• The exact same set of symptoms occur in which a
  narrowed coronary artery becomes completely
  blocked, usually by a blood clot.
• Heart muscle which formerly received blood from
  the blocked artery dies if deprived of oxygen for
  over 40-60 minutes.
• (An area of dead tissue resulting from a blocked
  artery is called an infarct).

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• If enough heart tissue dies, the heart may stop
  altogether (cardiac arrest, also known as sudden
  cardiac death).
• Although atherosclerosis is by far the most
  common cause of heart attack cardiac arrest,
  other causes include
• coronary artery spasm,
• electrical irregularities
• and congenital defects.

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• Everything else being equal, the risk of heart
  attack is
• doubled for a diabetic man
• and increased 5 times for a diabetic woman.
• Diabetes also doubles the risk of stroke
  independently from effects of heart disease and
  high blood pressure.
• (although good control of blood glucose can
  reduce the risk. )

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• Risk factors for cardiovascular diseases

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I. CIGARETTE SMOKING

• Heart attacks are 3 to 4 times more likely to
  occur in a cigarette smoker than in a nonsmoker
• and the smoker's heart attack is more likely to
  be fatal.
• The risk of cardiac arrest is
• 10 times greater for male smokers
• and 5 times greater for female smokers
• as it is for nonsmokers.

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Passive smoking

• Nonsmoking spouse of smokers have
• twice the incidence of heart disease and
• 2.5 times the incidence of lung cancer
• as nonsmoking spouses of nonsmokers

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• In the Framingham study
• male smokers were 40 more likely to suffer
  stroke than male nonsmokers
• and female smokers were 60 more likely to
  experience stroke than female nonsmokers.
• The lifespan of a smoker tends to be years less
  than that of a nonsmoker.

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• Tobacco smoke contains
• tar, nicotine,
• carbon monoxide, benzene,
• nitrogen dioxide, formaldehyde,
• hydrogen cyanide, nitrosamines and
• polycyclic aromatic hydrocarbons
• which are all known to be harmful

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• Many of these substances are capable of injuring
  the arterial endothelial cells to begin the
  atherosclerotic process.
• Nicotine causes
• adrenaline and nor-adrenaline release,
• which elevates heart rate and blood pressure.

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• Carbon monoxide binds to hemoglobin 200 times
  more strongly than oxygen thereby
• reducing the oxygen-carrying capacity of the
  blood
• and thickening the bloodstream through
  compensatory red blood cell proliferation.
• Smoking
• lowers the level of beneficial HDL-cholesterol
• and increases fibrinogen (promoting clotting).
• Even without coronary atherosclerosis, smoking
  can lead to cardiac arrest by
• causing the coronary arteries to go into spasm
• or by promoting irregularities of heartbeat.

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• Within one year of quitting smoking, the risk of
  heart attack falls 50.
• Within ten years, ex-smokers who smoked one pack
  per day or less have the same heart attack risk
  as those who have never smoked.
• And the extra risk of stoke is eliminated within
  5 years of kicking the cigarette habit.

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• Groups led by professional counselors have a 35
  greater success rate in a period of a year than
  smokers who try to quit by themselves.
• Groups that use nicotine chewing gum have an 80
  success rate.
• Most ex-smokers succeed only after several
  attempts to quit.
• A positive attitude to take after a failed
  attempt is to regard the failure as a learning
  experience -- and to incorporate what was learned
  by the failure in planning the next attempt.
• Only one-third of ex-smokers gain weight, and
  most of those don't keep the extra weight.

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II. HIGH BLOOD PRESSURE (HYPERTENSION)

• Blood pressure is regulated by the sympathetic
  and parasympathetic branches of the autonomic
  nervous system.
• In the sympathetic branch, pressure receptors in
  the aortic arch and the carotid arteries send
  signals to the vasomotor center of the brain
  stem.
• When blood pressure drops, sympathetic nerves to
  the heart release norepinephrine, which promotes
  calcium uptake by heart muscle and acts on beta
  receptors of the heart to increase the strength
  and rate of heartbeat.
• Sympathetic nerves also release norepinephrine to
  the alpha receptors of the arterioles, causing
  them to contract. All of these effects increase
  blood pressure.
• The parasympathetic branch sends the vagus nerve
  to the heart, where it releases acetylcholine,
  causing the heart to beat more slowly, and with
  less force.

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• The kidneys can influence blood pressure by
• (1) excreting more sodium and water (lowering
  blood
• volume, and hence, lowering blood
  pressure) and
• (2) secreting the enzyme renin which produces
• angiotension I in the bloodstream.
• When angiotension I reaches the lungs,
  Angiotension Converting Enzyme (ACE) converts
  angiotensin I to angiotension II, which rapidly
  and powerfully constricts the arterioles, raising
  blood pressure.

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• Blood pressure is measured by two values
• the highest pressure, when the heart is pumping
  or Squeezing (Systolic),
• and the lowest pressure, when the heart is
  relaxing or Dilating (Diastolic).
• A pressure of 140 mmHg is the amount of force
  necessary to raise a column of Mercury (Hg) 140
  millimetres.
• In North America, Systolic/Diastolic pressure of
  120/80 is considered "normal", although natives
  of New Guinea typically have a diastolic blood
  pressure of 60 mmHg -- and an extremely low
  incidence of stroke.

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The following table indicates the hazards of high
blood pressure

• __________________________________________
• YEARS OF LIFE LOST DUE TO HIGH BLOOD PRESSURE
• __________________________________________
• Sys/Dia MEN (age) WOMEN
  (age)
• 35 55
  35 55
• __________________________________________
• 130/90 4 years 1 year 2 years
  1 year
• 140/95 9 years 4 years 5 years
  3 years
• 150/100 17 years 6 year 9 years
  4 years
• __________________________________________

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• People with hypertension are 2-3 times more
  likely to have a heart attack than those with
  normal blood pressure.
• 45 of people with high blood pressure are
  unaware that they have it. Of those who are
  aware, fewer than half are being treated.
• People with uncontrolled high blood pressure are
  7 times more likely to have a stroke than people
  with controlled high blood pressure.
• Hypertension is the major risk factor for stroke.
  
• 25 of people currently undergoing kidney
  dialysis can blame high blood pressure for their
  kidney damage.
• High blood pressure also damages many other
  organs.

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III. Obesity

• 75 of overweight (over fat) people with
  hypertension who lost 20 pounds or more achieved
  normal blood pressure -- besides reducing their
  blood LDL and elevating their blood
  HDL-cholesterol.
• Will-power to resist the temptations of hunger is
  at least as important in losing weight as the
  will-power to exercise.
• Dieting should only be undertaken as a permanent
  life-style change because "yo-yo dieting" is
  associated with an increased incidence of heart
  attacks.

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IV. STRESS

• Twenty years ago 60 of heart attack victims
  blamed their attack on stress.
• It is more socially acceptable to blame stress
  (and it wins more sympathy) than to admit to
  one's eating and smoking habits.
• Large scale studies of high-level executives have
  not shown an increased incidence of heart
  disease.
• Prospective studies have failed to show that
  such major life events as "death of spouse",
  "divorce" or "fired from work" are predictors of
  heart disease.

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• Nonetheless, people with hypertension show
  greater blood pressure increases in response to
  stress than do people with normal blood pressure.
  

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• Relaxation and meditation can be learned and can
  lower blood pressure.
• People focusing conscious attention on their
  muscle groups can learn to relax them -- and
  people focusing conscious attention on their
  psychological straining (in meditation) can learn
  to relax that too.
• Relaxation techniques have been shown to lower
  systolic pressure by 11 mmHg and diastolic
  pressure by 7 mmHg.
• Even animals can be trained to lower blood
  pressure by use of biofeedback and rewards.

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V. Salt

• Although about 20 of the general population
  shows increased blood pressure with increased
  salt, the majority of persons with hypertension
  show a direct relationship between salt intake
  and blood pressure.
• More precisely, sodium from all sources (salt,
  MonoSodium Glutamate MSG, baking soda,
  antacids, etc.) increases blood pressure in about
  60 of hypertensive persons.
• The people of northern Japan, with a high-sodium
  diet (which included soy sauce, miso soup and
  pickled vegetables) had a 60 incidence of
  hypertension (the major cause of death was stoke)
  until a community-wide campaign taught people to
  alter their eating habits.

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• In the average diet, 77 of sodium comes from
  processed foods, 12 from meat vegetables, 6
  from table salt and 5 from cooking salt.
• A diet low in potassium or calcium may affect
  blood pressure as adversely as a high sodium
  diet. A banana or an orange provide as much
  potassium as a third of a cup of raisins -- for
  half the calories.
• Tomatoes are also high in potassium, and a tomato
  can give approximately the same potassium as a
  banana or orange -- for half the calories.

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VI. CHOLESTEROL

• Since the blood is 80 water, fats will not
  dissolve in blood.
• Therefore, fats need to be attached to carrier
  molecules to travel through the bloodstream.
• The principle carrier molecules for fat are
  albumin, chylomicrons, Very Low Density
  Lipoprotein (VLDL), Low Density Lipoprotein (LDL)
  and High Density Lipoprotein (HDL).
• Free Fatty Acids (FFAs) are attached to albumin,
  whereas triglycerides are mainly transported by
  chylomicrons and VLDL.
• Cholesterol and phospholipid are primarily
  transported by LDL and HDL.

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VI. CHOLESTEROL

• Free Fatty Acids are a major source of energy for
  many organs, including the heart.
• Triglycerides are hydrolyzed into FFAs and
  glycerol by the enzyme lipase, which is found
  both inside cells and on the surface of the
  endothelial cells of capillaries.

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VI. CHOLESTEROL

• Phospholipid is an essential constituent of cell
  membranes.
• Cholesterol is also an essential constituent of
  cell membranes, particularly in the nervous
  system.
• As well, cholesterol is the principal precursor
  of cortisone and sex hormones.
• Of the cholesterol in the body, 93 is in cells
  and only 7 is in plasma.

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VI. CHOLESTEROL

• Cholesterol is supplied to cells primarily by the
  attachment of LDL to specific LDL receptors on
  cell membranes.
• The Pima Indians of Nevada have diets high in
  fried foods - and have one of the highest obesity
  rates in the world -- yet the high level of LDL
  receptors on their cells leaves them with a heart
  attack rate which is only one-quarter the
  American national average.

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VI. CHOLESTEROL

• In the mid-1980s it was established that
• the condition known as familial
  hypercholesterolemia (seen in less than 1 of the
  population) is the result of a defect in the gene
  responsible for the LDL receptor.

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VI. CHOLESTEROL

• Thyroid hormone lowers blood cholesterol by
  increasing the number of LDL receptors on cells.
• For most people, atherosclerosis due to excessive
  LDL-cholesterol in the blood is the result of a
  high level of dietary saturated fat resulting in
  high LDL-cholesterol production by the liver.

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VI. CHOLESTEROL

• The primary function of HDL seems to be to remove
  excess cholesterol from the bloodstream.
• LDL can directly release cholesterol into
  arterial areas made porous by prostaglandins --
  whereas HDL can scoop-up this loose cholesterol
  and return it to the liver.
• Thus, HDL deficiency can be as serious an
  atherosclerosis risk as LDL-cholesterol excess.

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VI. CHOLESTEROL

• A 1 reduction in blood cholesterol is generally
  associated with a 2 reduction in risk of
  coronary artery disease, within "normal" North
  American levels of blood cholesterol.
• A one mg/dl (0.26 mmol/Litre) increase in blood
  HDL reduces the risk of coronary artery disease
  by 2 to 3 percent.

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VII Estrogen

• Estrogen produced by the ovaries (estradiol)
  increases HDL and reduces LDL, probably by
  increasing the number of LDL receptors in the
  liver (removing LDL from the blood).
• Estradiol is believed to be the main reason why
  pre-menopausal women have such a lower incidence
  of heart disease than men.

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• Men given estrogen therapy had an increase in
  coronary disease mortality.
• Birth control pills used in the 1980s increased
  the incidence of heart disease due to the
  anti-estrogen effect of synthetic progestin used.
• Newer synthetic progestins seem to have
  eliminated this problem.

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Hormone Replacement Therapy

• HRT with estrogen reduces some of the discomfort
  associated with the onset of menopause (hot
  flashes, vaginal drying thinning and urinary
  tract infections), but was shown in the 1970s to
  increase the risk of endometrial (lining of the
  uterus) cancer by 6-8 times.
• In 2002 a large-scale study was halted due to
  mounting evidence that HRT combining estrogen
  progestin in women with a uterus (no
  hysterectomy) increased strokes 41, heart
  attacks 29 and breast cancer 26, while reducing
  colorectal cancer 37 and hip fractures 33

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VIII. DIET

• Most cholesterol in the blood is manufactured in
  the liver.
• If dietary cholesterol is too low, the liver
  manufactures more, and if dietary cholesterol is
  too high, the liver manufactures less.
• But the compensation is not complete, and dietary
  cholesterol does influence levels of cholesterol
  in the blood.

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• Cholesterol is found in the tissue of animals,
  not plants -- specifically it is found in the
  muscle portion of meat, not in the fat.
• Egg yolks and organ meats have about the highest
  cholesterol content of any foods.

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• Saturated fats and artificially hydrogenated
  polyunsaturated fats raise blood cholesterol far
  more dramatically than cholesterol itself -- by
  increasing the manufacture of LDL-cholesterol in
  the liver.
• Animal fat (especially red meat and butter) and
  tropical oils (palm, coconut and chocolate) have
  the most saturated fat.

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• Polyunsaturated fat lowers both LDL and HDL
  blood cholesterol, whereas monosaturated fat
  lowers LDL without lowering HDL cholesterol.

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• Considering the potential damage due to
  free-radical oxidation by polyunsaturated fat,
  monosaturated fat becomes by far the most
  desirable option -- although reduction of all fat
  is probably the best option of all.
• Olive oil is 80 monosaturated fat and canola oil
  is 65 monosaturated.

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• Because LDL-cholesterol oxidation increases
  atherosclerosis formation, daily doses of the
  antioxidants Vitamin C, Vitamin E and
  beta-carotene reduces heart disease risk.

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• In a survey of nearly 90,000 female nurses, those
  in the upper fifth with respect to Vitamin E
  intake had 2/3 the risk of major coronary disease
  as those in the lower fifth.
• A similar study of nearly 40,000 male health
  professionals showed those consuming over 60 IU
  of Vitamin E daily had less than 2/3 the risk of
  coronary disease as those consuming less than
  7.5 IU daily .
• Vitamin C helps to regenerate Vitamin E.

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• Animals fed fat-free diets display
  deficiency-disease symptoms that are completely
  eliminated by feeding them small quantities of
  the essential fatty acids linolenic, linoleic
  and arachidonic acid, all of which are
  20-carbon-length polyunsaturated fatty acids.
• These are probably essential for health by being
  precursors of the 20-carbon-length eicosanoids
  (local hormomes)
• prostaglandins,
• prostacyclin,
• thromboxanes, lipoxins and leukotrienes.

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• Soluble fiber has been shown to lower blood
  cholesterol.
• The pectin in apples, pears, oranges, grapefruit
  and bananas is soluble fiber as is the glucan in
  oat bran, peas, beans and whole wheat spaghetti
  and as is the psyllium in the laxative Metamucil.
  

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• Over a six week period, adults with high blood
  cholesterol showed a 16 drop in LDL-cholesterol
  with 57 grams of oat bran daily, and an 11.5
  drop with 85 grams of oatmeal daily.
• One teaspoonful of Metamucil once or twice daily
  has been shown to reduce cholesterol 5.

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• The Omega-3 fatty acids lower blood
  triglycerides, but their main benefit for
  preventing heart disease by being a precursor of
  prostaglandin, which inhibits platelet
  aggregation and dilates blood vessels.
• Although these fatty acids are present in fish,
  the richest source is linseed (flaxseed) oil,
  which is 55 linoleic acid.

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• Nonetheless, the advantages of reduced clotting
  for heart disease may be undermined by the
  dangers of excessive bleeding (especially for
  people at risk of cerebral hemorrhage).
• Moreover, omega-3 oils in large doses depress the
  immune system and have been associated with
  scarring of heart muscle in animal studies.
• The main advantage gained by following the
  recommendation to eat fish several times weekly
  may be that it reduces the consumption of animal
  meat.

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IX. COFFEE AND ALCOHOL

• Boiled coffee has been shown to increase blood
  cholesterol by 10, whereas filtered-coffee has
  no such effect.
• The difference is due to "coffee fat" in the
  former, which in purified form can increase blood
  cholesterol dramatically.
• A study of 1,130 male medical students showed a
  2-3 fold greater risk of coronary artery disease
  among those who drank more than 5 cups of coffee
  per day (the study doesn't reveal whether the
  coffee was boiled or filtered).
• But the increased cardiovascular risk associated
  with high coffee consumption applied only to
  nonsmokers.
• Caffeine is known to promote atrial fibrillation
  in some persons.

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XI. EXERCISE

• A study of 6,000 San Francisco longshoreman
  showed that light workers had 2.5 times as many
  fatal heart attacks and 3 times the incidence of
  sudden cardiac death as moderate or heavy
  workers.
• Another study divided 4,000 healthy men aged 30
  to 69 into 4 quartiles by fitness. In the
  subsequent 8 years, the lowest quartile had 8.5
  times the cardiovascular death rate as the
  highest quartile, even after smoking, cholesterol
  and blood pressure were factored-out.
• In Framingham, the 16 of males and 21 of
  females who lived the most sedentary lives had
  3.5 time the rate of coronary artery disease.

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• When a person is at rest or engaged in light
  activity, muscles primarily utilize Free Fatty
  Acids (FFAs) as their energy source.
• This is an aerobic process (ie, it uses oxygen).
  The term "aerobic" also refers to aerobic
  glycolysis (glucose/glycogen metabolism) as
  opposed to anaerobic glycolysis.
• Extremely intense and vigorous exertion may place
  demands on muscle that are in excess of those
  which could be met with available oxygen.
• Nature has provided the mechanism of anaerobic
  glycolysis as a source of spurts of energy that
  are potentially of survival value in critical
  "fight or flight" situations.
• In a 100-metre dash that takes 10 seconds, 85 of
  the energy is derived anaerobically, a 2-mile
  race lasting 10 minutes would use 20 anaerobic
  energy, and a 60-minute long-distance race would
  use 5 anaerobic energy (95 aerobic energy).

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• Anaerobic exertion is intense and short-lived.
• It produces lactic acid which inhibits enzymes,
  making further exertion difficult.
• A person will be "winded" until the "oxygen debt"
  is repaid.
• Anaerobic exertion is not particularly beneficial
  for the cardiovascular system.
• Sustained, moderately intense exertion that
  allows for high oxygen exchange is very
  beneficial.
• Aerobic exercise is also of value in eliminating
  fat, because after 10 minutes glycogen stores
  begin to drop, and after 30 minutes most of the
  muscle fuel comes from breakdown of triglycerides
  from fat stores.
• It is probably good to take anti-oxidants prior
  to aerobic exercise, to reduce resulting
  free-radicals.

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• Care should be taken not to begin an exercise
  program that involves excessive exertion which
  the subject is not used-to.
• A heart attack due to unusual strain defeats the
  purpose.
• Five minutes of initial stretching is important
  to avoid pulling muscles.
• A warm-up period avoids initial strain and a
  cool-down period is even more important.
• Stopping exercising too suddenly can dramatically
  reduce venous return of blood to the heart
  (because muscular contractions propel blood in
  the veins), which can provoke a heart attack if
  the heart's own oxygen needs are not being met.

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XII. ASPIRIN

• The main effect of aspirin is to block production
  of the short-acting "local hormone" thromboxane
  -- resulting in reduced platelet aggregation
  (clotting) and reduced artery constriction.
• This is seemingly of value to prevent heart
  attacks, although it does not seem advisable for
  those at risk of hemorrhagic stroke.
• In fact, by aspirin use risk of death has been
  reduced 15 among survivors of heart attack,
  stroke, TIA and unstable angina. The benefit of
  aspirin for others is debatable.
• A well-publicized study of 22,000 American male
  physicians taking 325 mg of aspirin on alternate
  days showed 44 fewer heart attacks, but no fewer
  cardiac arrests or total cardiovascular deaths.
• A similar study with British male physicians
  taking 500 mg aspirin daily failed to show
  reduction in heart attacks.
• Both studies showed higher incidence of
  hemorrhagic stroke and bleeding ulcers with
  aspirin.

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XIII. DIAGNOSTIC TOOLS

• Few people need to wait until a heart attack to
  discover that they have heart problems.
• Many means of examining the heart are available.
• ElectroCardioGraphy (ECG) displays the "P-QRS-T"
  waves of heart rhythm.
• ECG tests are especially effective when done as
  part of an exercise stress test, where the ECG is
  measured while the patient walks at a fast pace
  on a treadmill.
• An exercise stress test correctly identifies the
  presence of coronary artery disease 70 of the
  time, and correctly identifies the absence of
  coronary artery disease 90 of the time.
• An exercise stress test can also reveal
  electrical instability in heart rhythms.

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Normal ECG
76

• Chest X-rays can reveal the calcium deposits of
  advanced coronary arteriosclerosis.
• In radionuclide scanning, a small amount of
  radioactive thallium is injected so that the
  pumping efficiency of the heart can be visualized
  with a Gamma camera.
• Echocardiography uses ultrasound waves reflected
  (echoed) from the heart to examine functioning
  heart structures, particularly the valves.
• Computed Tomography (CT, or "CAT scanning") uses
  an X-ray machine that is rapidly rotated around
  someone's body to produce computer-constructed
  images of the heart or brain in "slices" (like
  sliced bread).
• Magnetic Resonance Imaging (MRI) uses magnetic
  fields and radiowaves rather than X-rays to
  produce similar results as CAT scanning.
• Positron Emission Tomography (PET) visualizes
  tissue metabolism, but it is still too expensive
  to be used in routine medical examinations.
• Direct assessments of the heart can be made by
  inserting catheters.

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• People often have myocardial infarctions that
  involve such small portions of the heart that
  they experience no symptoms and are completely
  unaware that it happened.
• Nonetheless, such an event is often preliminary
  to a more serious heart attack.
• Damaged heart cells leak enzymes into the
  bloodstream, such as
• Creatine PhosphoKinase (CPK),
• Lactic DeHydrogenase (LDH) and
• Serum Glutamic Oxaloacetic Transaminase (SGOT).
• Blood Urea Nitrogen (BUN) and creatinine often
  indicate kidney damage due to high blood
  pressure.
• Blood tests often indicate problems before
  changes are apparent on an electrocardiogram.

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XIV. MEDICAL INTERVENTION

• Drug therapy can be used to lower cholesterol,
  reduce hypertension and prevent clotting.
• For patients with serious blockage of the left
  main coronary artery, bypass surgery will
  increase expected 50 survival time from 5 to 10
  years (which can buy time for advances in
  artificial hearts or other alternatives).
• Coronary angioplasty uses a catheter with a
  balloon tip to mechanically enlarge coronary
  arteries.
• An atherectomy catheter uses a rotating disk to
  shave-off atheromas.
• Catheters with laser tips vaporize plaque which
  dissolves in the bloodstream and is eliminated as
  natural body waste.

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• Pacemakers can be implanted on hearts that do not
  have a well-controlled natural electrical rhythm.
  
• External defibrillators can be worn which detect
  heart stoppage or electrical irregularity and
  apply a shock to restart the heart.
• Fibrinolytics administered within a few hours of
  a heart attack will dissolve clots in the artery.
  
• Streptokinase and
• tissue plasminogen activator (t-PA) are most
  widely used for this purpose.
• Concomitant injection of heparin seems to enhance
  the effectiveness of these agents.

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For optimal health, health professionals recommend

• Maintaining a healthy weight, with a body mass
  index (BMI) of 18.524.9.
• Limiting dietary fat to 30 percent or less of
  total calories10 percent saturated fat, 10
  percent polyunsaturated fat, and 10 percent
  monounsaturated fats. Consumers should be aware
  that ounce for ounce, all sources of fat have
  approximately the same amounts of calories.
• Limiting saturated fats to 10 percent of
  calories. Saturated fats come primarily from
  animal sources (e.g., high-fat dairy and meats),
  but also are found in coconut and palm oil.

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• Limiting polyunsaturated fats to 10 percent of
  calories. Polyunsaturated fats come primarily
  from vegetable oils (e.g., corn oil, safflower
  oil).
• Limiting monounsaturated fats to 10 percent of
  calories. Monounsaturated fats may have a
  protective role in heart disease. Excellent
  sources of monounsaturated fats include olive
  oils, nuts, avocado, and canola oil.
• Increasing intake of omega-3 fatty acids. Two to
  four grams daily of omega-3 fatty acids may lower
  risk for CVD by reducing blood clotting, making
  platelets less sticky, and lowering
  triglycerides. Patients should inform their
  physician if they are using omega-3 supplements,
  since they may increase the risk of bleeding.
• Excellent sources of omega-3 include fatty fish
  (such as salmon and sardines), fish oils, and
  flax seed.

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• Limiting sodium intake to 2,400 milligrams per
  day.
• Increasing potassium intake to at least 3,500
  milligrams per day.
• Eating at least five servings a day of fruits and
  vegetables.
• Eating a plant-based diet consisting primarily of
  whole grains, fruits, and vegetables is also
  recommended.
• Eating at least 25 grams of fiber daily.
• Eating 25 grams of soy protein daily.