Download Chapter 2 - Preventing Cardiovascular Disease

Preventing
Cardiovascular Disease
Chapter 2
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Cardiovascular Disease

the leading cause of death in the U.S.—
37.3% of all deaths

Approximately 25% of Americans have one or
more forms of heart or blood vessel disease.

Approximately 330,000
people die annually of
coronary heart disease
(CHD).
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The Heart

Consists of cardiac muscle

Weighs 8 to 10 ounces

Has two halves (pumps)
divided by the septum

Halves are divided into upper chambers
(atria) and lower chambers (ventricles)
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Circulation
The primary function of circulation is to provide a constant supply of
blood and nutrients to cells while removing their waste products


The left side of the heart
(systemic pump) receives
the oxygenated blood
from the lungs and
pumps it to all the tissues
in the body
The right side of the
heart (pulmonary pump)
receives deoxygenated
blood from the body and
pumps it to the lungs
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Circulation

The heart has its own
conduction system

The beating rate and
rhythm are established by
the sinoatrial (SA) node
(pacemaker)

The electrical contraction
pauses at the
atrioventricular (AV)
node, allowing the
ventricles to fill with
blood
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Circulation

The heart is supplied
with blood from
coronary circulation
after it has been
ejected from the heart

Blood is so important to
the heart that every
muscle fiber is supplied
by at least one capillary
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Cardiovascular Disease

Coronary heart disease (coronary artery
disease; CAD) is diagnosed when any artery
is narrowed by 60% or more

A myocardial infarction (heart attack; death
of the heart muscle) occurs when blood flow
to the heart muscle is disrupted

Most heart attacks occur after age 65, but
the problems leading up to them begin as
early as adolescence
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Myocardial Infarction
The medical term for heart attack is myocardial infarction (MI)

Up to one third of all heart attacks are
silent—without obvious signs or symptoms
– Silent ischemia, reduced blood flow, can
initiate heart attacks without warning
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Cardiovascular Disease (2)

Americans as young as 8 have
obstructions in their coronary arteries
caused by atherosclerosis
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Stroke (Brain Attack)

Strokes are caused by a thrombus or an
embolus (70% to 80%) or a cerebral
hemorrhage

Brain cells die, causing loss of function of
some parts of the body

Strokes have similar risk and prevention
factors as heart disease
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Unchangeable Risk Factors for
Heart Disease

Age
– 55% of heart attacks occur after age 65

Male gender
– Heart disease is the leading cause of death for both
males and females
– Females have a lower rate than males
– Rate is increasing among females, particularly those
who smoke and use oral contraceptives

Heredity & Race
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Major Risk Factors That Can Be
Changed
 Cholesterol
is a steroid that does not
dissolve in blood, so it is transported to
cells by protein packages
 A certain amount of cholesterol is
necessary for good health
– The best way to lower serum (blood) cholesterol is to
reduce intake of saturated fat
– Saturated fat increases the liver’s production of
cholesterol
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Major Risk Factors That Can Be
Changed

Low-density lipoproteins (LDL), the
primary transporters of cholesterol, are
the most capable of producing
atherosclerosis

People with low blood levels of LDL (less
than 100 mg/dl) rarely have heart attacks
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More Risk Factors That Can Be
Changed:
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Blood Pressure (1)

Blood pressure is the force exerted against
artery walls as blood travels through the
circulatory system
– High blood pressure (hypertension) has no signs or
symptoms
– An estimated 90% to 95% of hypertension is
essential (of unknown origin)
– Prehypertension includes blood pressures ranging
from 120/80 to 139/89
– Hypertension= 140/90 mmHg
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Blood Pressure (2)
Long-term uncontrolled
hypertension increases the work
of the heart, causes it to
hypertrophy, and leads to
congestive heart failure
 Hypertension is the most
important risk factor for strokes

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Cigarette Smoking/Tobacco Use

Cigarette smoking is considered to be the
most harmful of the preventable risk factors
for chronic illness and premature death
– These illnesses include chronic bronchitis, emphysema,
strokes, and 87% of all lung cancers
– Loss of life from smoking represents a life expectancy
drop of ~18%

Passive smoking, inhaling the smoke of
others, causes the deaths of 38,000 to
43,000 nonsmokers annually
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Physical Inactivity

Physical inactivity increases the risk of coronary
heart disease by 1.5 to 2.4 times

The greatest health benefits are gained when
people expend 1500 to 2000 calories (walk 15
to 20 miles) per week

Exercise for health does not have to be as
strenuous as exercise for physical fitness
– But physical fitness is an important factor in
cardiovascular health
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Physical Inactivity

Physical activity is any physical movement
that results in energy expenditure—
walking, mowing the lawn, vacuuming

“Every U.S. adult should accumulate 30
minutes or more of moderate intensity
physical activity on most, preferably all,
days of the week.” (ACSM/CDC
statement)
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Obesity

Obese people who have no other risk factors
are still more likely to develop heart disease
or stroke.

Fat that accumulates in the upper half of the
body (central abdominal obesity) is
significantly more likely to contribute to heart
disease

A 5% to 10% weight loss that is maintained
can significantly reduce the risk of heart
disease
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Diabetes Mellitus

Diabetes is a metabolic disorder in which the
body cannot properly use sugar (glucose) as
fuel

Type II (90% of all diabetes) typically occurs
in older, overweight, sedentary adults
– It is being seen more and more in children,
adolescents, and young adults

Diabetes increases the risk of coronary artery
disease 2 to 4 times that of non-diabetics
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Changeable Risk Factors
Stress

Stress elevates heart rate, blood pressure, breathing
rate, and blood sugar levels, activates the immune
response, and causes other physiological changes

Chronic (long-term) distress significantly strains the
body
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Preventable / Changeable Risk
Factors:
Cholesterol
 Blood Pressure
 Cigarette Smoking/Tobacco Use
 Physical Inactivity
 Obesity
 Diabetes Mellitus
 Stress

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Preventing and Reversing Heart Disease
Preventing includes:
 Exercising regularly
 Maintaining an optimal
body weight
 Practicing sound nutrition
 Nonuse of tobacco and other drugs
 Nonuse or moderate use of alcohol
 Dealing constructively with stress
 Periodic medical examinations
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Preventing and Reversing Heart Disease
Reversing includes:
 Following a low-fat diet
 Stopping tobacco use
 Managing stress
 Attending support group
meetings regularly
 Exercising consistently at a
moderately intense level
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Other Risk Factors
Other factors include:
 Iron-enriched blood
 Homocysteine
 Lipoprotein
 High Sensitivity C-Reactive
Protein
 Fibrinogin
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Diagnostic Techniques

Medical examination and patient history

Exercise stress tests

Thallium treadmill test

Echocardiography

Cardiac catheterization
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Medical Treatment







Low-dose aspirin therapy
Coronary artery bypass
surgery
Balloon angioplasty
Coronary stent
Artificial valves
Left ventricular assist devices
Heart transplants
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Preventing Cardiovascular Disease
Chapter 2
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