Encyclopedia of Health and Medicine

102 The Cardiovascular System
ally restores normal circulation and ends the
symptoms. Stress and anxiety may sometimes initiate
the symptoms. Relaxation methods such as
MEDITATION are helpful when this is the case.
BIOFEEDBACK is effective for some people, and regular
physical exercise helps maintain circulation.
When Raynaud’s syndrome fails to respond to
preventive and lifestyle measures, doctors may
prescribe medications such as beta blockers, calcium
channel blockers, or topical nitroglycerin to
relax the arterioles. Treating any underlying conditions
helps mitigate the symptoms of Raynaud’s
syndrome.
See also MEDICATIONS TO TREAT CARDIOVASCULAR
DISEASE; NEUROPATHY; PULMONARY HYPERTENSION;
SMOKING AND CARDIOVASCULAR DISEASE.
risk factors for cardiovascular disease The circumstances
that make a person more or less likely
to develop conditions affecting the HEART and cardiovascular
system. A risk factor may be fixed, or
immutable, such as age, ethnicity, or gender.
Other risk factors are variable, or mutable. These
are the risk factors that an individual can influence,
such as dietary habits and physical activity.
Doctors also use the terms alterable and nonalterable,
respectively. Other health conditions may
also become risk factors for CARDIOVASCULAR DISEASE
(CVD), notably DIABETES. Certain cardiovascular
conditions, such as HYPERTENSION (high BLOOD PRES-
SURE) and ATHEROSCLEROSIS, are risk factors for
other cardiovascular conditions such as STROKE and
HEART ATTACK.
CARDIOVASCULAR DISEASE RISK FACTORS
Fixed
male
age 60 and older
genetic predisposition
African American heritage
Native American heritage
female postmenopause
Variable
cigarette smoking
OBESITY
physical inactivity
HYPERLIPIDEMIA (elevated blood
lipid levels)
HYPERTENSION (high BLOOD
PRESSURE)
DIABETES
More than 90 percent of cardiovascular disease
among Americans develops over decades, the consequence
of interactions between genetic predisposition
and lifestyle. Health experts believe
lifestyle choices can prevent nearly all of such
acquired cardiovascular disease, even when there
are genetic influences. The HUMAN GENOME PROJ-
ECT, the mapping of the human genome, has
broadened scientific understanding of genes and
of how they influence health and disease.
Researchers are better able to assess and even
manipulate the interplay between certain genetic
factors and lifestyle factors. One area of ongoing
genetic research is ethnicity. Though the rate of
CVD is significantly higher among people of certain
ethnic heritages, the reasons remain unclear.
Though individuals cannot alter genetic predisposition
for health conditions, they can often mitigate,
through lifestyle, the ways in which such
predispositions play out in their lives. A person
who has a family history of early-onset atherosclerosis,
for example, may mitigate the effects of this
genetic predisposition through daily moderate
exercise (aerobic and STRENGTH) and dietary habits
that limit fat consumption to less than 10 percent
of daily calories and increased fiber consumption,
as well as through maintaining healthy body
weight. Other preventive measures may include
frequent blood lipid level screening (every 6 to 12
months) and lipid-lowering medications for lipid
levels that remain elevated despite lifestyle efforts
to keep them low. These lifestyle efforts can minimize,
and often prevent, cardiovascular disease.
An important dimension to risk factors for CVD
is the interplay that exists among them. Physical
inactivity is a key element in the development and
progression of HYPERLIPIDEMIA, type 2 DIABETES, OBE-
SITY, and hypertension. Hyperlipidemia lays the
foundation for atherosclerosis, which progresses to
CORONARY ARTERY DISEASE (CAD). CAD causes
ISCHEMIC HEART DISEASE (IHD) and is the leading
cause of heart attack. Hypertension, alone though
especially in combination with atherosclerosis
(CAD or PVD), is the leading cause of stroke.
Congenital heart conditions, even those
repaired in early childhood, may predispose people
to other forms of cardiovascular disease later
in life. Adults under age 30 are the first generation
for whom surgical correction of congenital heart
defects was a viable treatment option. Doctors do
not yet know the extent to which these anomalies
may affect future cardiovascular risk.