Transcript Cardiovascular Disease - McGraw Hill Higher Education

Cardiovascular Health
Chapter 15
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Cardiovascular disease (CVD)
› Leading cause of death in the U.S.
› Affects nearly 81 million Americans
› Claims one life every 38 seconds
› About 2,300 Americans die every day
› CVD is largely due to our way of life
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Consists of the heart and blood vessels
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With lungs, known as the cardiorespiratory system
The Heart
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Four-chambered, fist-sized muscle located just beneath the sternum
Blood travels through two separate circulatory systems:
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Pulmonary circulation
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Right side of heart pumps blood to lungs.
Systemic circulation
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Left side of heart pumps blood through the rest of the body
Path of blood flow:
1.
2.
3.
4.
5.
6.
7.
Through venae cavae into atrium (right upper chamber)
From atrium to ventricle (right lower chamber)
Pulmonary artery to the lungs
In lungs, picks up oxygen and discards carbon dioxide
Through pulmonary veins into heart’s left atrium
Left atrium fills, pumps blood into left ventricle
When left ventricle full, pumps blood through aorta for
distribution to the rest of the body’s blood vessels
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Systole
› The heart’s contraction
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Diastole
› The period of relaxation
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Blood pressure
› Force exerted by blood on the walls of
the blood vessels, created by pumping
action of the heart
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Heartbeat
› Controlled by nerve impulses
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Blood Vessels (classified by size and function)
› Veins
 Carry blood to the heart
 Thin walls
› Arteries
 Carry blood away from the heart
 Thick elastic walls expand and relax with the volume of blood
 Coronary arteries
 Two large vessels that supply blood to the heart
› Capillaries
 Smallest arteries, only one cell thick
› Venules
 Blood empties from capillaries into venules that connect to veins
that return the blood back to the heart
› 150-pound person has about 5 quarts of blood that circulates
about once each minute
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Two categories of increased risk for CVD
1.
2.
Major risk factors
Contributing risk factors
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Controllable aspects of lifestyle that can be changed
Major risk factors that can be changed
› American Heart Association identified six major risk
factors.
1. Tobacco use
2. High blood pressure
3. High cholesterol
4. Physical inactivity
5. Obesity
6. Diabetes
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1 in 5 deaths from CVD is a smoker
Smokers have 2 to 3 times higher risk of death from
a heart attack than do nonsmokers
Smoking doubles risk of stroke
Damages the lining of arteries
Reduces HDL (“good” cholesterol)
Raises triglycerides and LDL
Nicotine increases blood pressure and heart rate
CO displaces O2
Causes platelets to become sticky and increases
blood thickness
Speeds the development of fatty deposits in the
arteries
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Hypertension
› Too much pressure against blood vessel walls
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Short periods of high blood pressure are normal,
but chronic high blood pressure is a health risk
Atherosclerosis
› Heart has to work harder, weakens, enlarges, arteries
narrow, scar, and harden
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About 33% (73 million) of adults have hypertension
37% of adults have prehypertension
Test your blood pressure at least once every two
years
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Fatty, waxlike substance that circulates through the
bloodstream
› Important component of:
 Cell membranes
 Sex hormones
 Vitamin D
 Fluid that coats the lungs
 Protective sheaths around nerves
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Excessive cholesterol clogs the arteries
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Good versus bad cholesterol
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Recommended blood cholesterol levels
Benefits of controlling cholesterol
› Increased risk of CVD
› Low –density lipoproteins (LDL) (“bad” cholesterol)
 Shuttle cholesterol from the liver to organs and tissues
› High-density lipoproteins (HDL) (“good” cholesterol)
 Shuttle unused cholesterol back to the liver for recycling
 By removing cholesterol from blood vessels, HDL helps
protect against atherosclerosis
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40-60 million Americans are so sedentary that they
are at high risk for developing CVD
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Exercise reduces risk
› Closest thing we have to a magic bullet against
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heart disease
Controls blood pressure and resting heart rate
Lowers LDL
Increases HDL
Maintains weight
Improves the condition of blood vessels
Helps prevent or controls diabetes
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Risk of death from CVD is two to three times more
likely in obese people (BMI ≥ 30)
Increased strain on the heart
Strongly associated with:
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Hypertension
High cholesterol
Insulin resistance
Diabetes
Physical inactivity
Increasing age
Endothelial cell dysfunction
 Coronary arteries constrict instead of dilate
› Hypertrophy (ventricular enlargement)
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Doubles the risk of CVD for men
Triples the risk of CVD for women
Loss of 5-10 years off your life
Higher risk
Hypertension
Obesity
Unhealthy blood lipid levels
Elevated blood glucose and insulin can
damage the endothelial cells lining the arteries
› More vulnerable to atherosclerosis
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High triglyceride levels
› Blood fats that are a reliable predictor of heart disease
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Psychological and social factors
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Stress
Chronic hostility and anger
Suppressing psychological distress
Depression
Anxiety
Social isolation
Low socioeconomic status
Alcohol and drugs
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Heredity
› CVD has genetic component; high cholesterol levels,
hypertension, diabetes, and obesity
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Aging
› Over the age of 65
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Being male
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Men have higher risk earlier in life
Ethnicity
› African Americans higher risk of hypertension;
Hispanics greater risk of HBP and angina;
Asians lower rates of CVD
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Insulin resistance and metabolic syndrome
Homocysteine
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Infectious agents
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Lipoprotein(a) – Lp(a)
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LDL particle size
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Blood viscosity (thickness) and iron
Uric acid
Time of day and time of year
› Amino acid circulating in the blood
› Chlamydia pneumoniae – flulike respiratory infections
› Strong genetic component
› Particles differ in shape and size
› More heart attacks and sudden death occur between 6:00AM
and noon
› 50% more occur in winter months than in summer months
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Atherosclerosis - narrowed by fatty deposits
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Plaques accumulate in artery walls
Coronary heart disease (CHD)
Coronary artery disease (CAD)
Peripheral arterial disease (PAD)
Heart attack – heart tissue is damaged and part of it
may die from lack of blood
› Myocardial infarction (MI)
› American Heart Association
 785,000 people have a first heart attack each year
 470,000 people have recurrent attack
 195,000 people suffer a symptomless or “silent” heart attack
each year
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Chest pain or pressure
 Arm, neck, or jaw pain
 Difficulty breathing
 Excessive sweating
 Nausea and vomiting
 Loss of consciousness
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Angina – arteries narrowed by disease, but under
stress heart cannot receive enough oxygen
› Angina pectoris
› Usually felt as an extreme tightness in the chest and
heavy pressure behind the breastbone or in the
shoulder, neck, arm, hand, or back
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Arrhythmias and sudden cardiac death – electrical
conduction system is disrupted
› Sudden cardiac death (cardiac arrest) often caused by
an arrhythmia called ventricular fibrillation
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Most victims die within 2 hours from initial
symptoms
 Give one adult aspirin tablet (325 mg)
 Cardiopulmonary resuscitation (CPR)
 Refer to Take Charge box “What to Do in
Case of a Heart Attack, Cardiac Arrest,
or Stroke”
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Electrocardiogram (ECG or EKG)
Electron-beam computed tomography (EBCT)
Echocardiography – sound waves
Multi-slice computed tomography (MSCT)
Magnetic resonance imaging (MRI)
Nuclear myocardial perfusion imaging
Positron Emission Tomography (PET)
Angiogram
Balloon angioplasty
Coronary bypass surgery
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2 million brain cells die per minute during a
stroke
 Ischemic stroke – blockage in a blood vessel
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› Thrombotic stroke - clot forms in a cerebral artery
› Embolic stroke - wandering blood clot
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Hemorrhagic stroke - blood vessel ruptures in the
brain
› Intracerebral hemorrhage
› Subarachnoid hemorrhage
› Aneurysm
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Interruption of the blood supply to any area
of the brain prevents the nerve cells from
functioning, in some cases causing death
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Usually suffer some lasting disability
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Paralysis
Walking disability
Speech impairment
Memory loss
Changes in behavior
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Prompt recognition of symptoms:
› Sudden numbness or weakness of face, arm,
leg, or one side of the body
› Loss of speech or difficulty speaking
› “Three Simple Ways to Recognize a Stroke”
1.
2.
3.
Ask the person to smile. If her smile droops on one
side, or if she is unable to move or open one side of
her mouth, she may be having a stroke.
Ask the person to hold his arms out. If the person
cannot move one arm or hold one arm still, it may be
a sign of a stroke.
Ask the person to repeat a simple sentence, such as
“Take me out to the ball game.” If she has trouble
speaking or cannot speak, a stroke is possible.
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Transient ischemic attack (TIA)
› Temporary stroke-like symptoms (ministroke)
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Computed tomography (CT)
MRI
Ultrasound
Drugs
Carotid endarterectomy surgery – plaque is
removed from the artery
Rehabilitation
› Physical therapy
› Speech and language therapy
› Occupational therapy
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PAD – atherosclerosis in the leg (or arm) arteries,
which can limit or block the blood flow
Patients typically also have coronary artery disease
About 8 million people in the U.S. have PAD
Risk factors:
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Smoking
Diabetes
Hypertension
High cholesterol
Symptoms
› Claudication (aching or fatigue in the affected leg)
› Rest pain (limb artery cannot supply enough blood at rest)
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Number of conditions
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High blood pressure
Heart attack
Atherosclerosis
Alcoholism
Viral infections
Rheumatic fever
Birth defects
Pulmonary edema - fluid accumulates in the lungs
› Heart can not maintain regular pumping rate; fluid backs up
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Controlled by:
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Reducing cardiac load
Eliminating excess fluid
Restriction of salt
Drug therapy
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Congenital heart defects
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Hypertrophic cardiomyopathy (HCM)
› Malformation of the heart or major blood vessel
› Occurs in 1 out of 500 people
› Most common cause of sudden death in athletes younger
than 35
› May be identified by a murmur
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Rheumatic heart disease
› Streptococcal infections cause damage to the heart muscle
and valves
› Strep throat needs to be treated
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Heart valve disorders
› Congenital heart defects and certain types of infections
› Mitral valve prolapse
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Eat heart-healthy
 Decrease fat and cholesterol
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› Total fats less than 30% of total calories
› Low saturated fats
Increase fiber intake
 Decrease sodium intake and increase
potassium intake
 Moderation of alcohol
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Omega-3 fatty acids
Plant stanols and sterols
Folic acid
Vitamins B-6 and B-12
Calcium
Soy protein
Healthy carbohydrates
Total calories
DASH
› Dietary Approaches to Stop Hypertension
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Moderate physical activity
 Avoid tobacco
 Know and manage your blood pressure
(monitor once every two years)
 Know and manage your cholesterol
levels
 Develop effective ways to handle
stress and anger
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