Encyclopedia of Health and Medicine

22 The Cardiovascular System
nostic path typically includes CARDIAC CATHERIZA-
TION or vascular catheterization, which allows the
cardiologist to directly visualize the extent of atherosclerotic
disease present. ELECTRON BEAM COM-
PUTED TOMOGRAPHY (EBCT) SCAN, a noninvasive
imaging procedure, shows promise for identifying
atherosclerosis in its early stages. EBCT detects
calcium in the atherosclerotic deposits.
Treatment Options and Outlook
Treatment may target the damaged arteries, the
underlying disease process, or both. Treating the
damaged artery generally takes precedence as
the atherosclerotic occlusions restrict and may
even block the flow of blood.
Risk Factors and Preventive Measures
The primary risk factor for atherosclerosis is elevated
cholesterol blood levels, which allow fatty
acids to accumulate in the blood. Cigarette smoking,
OBESITY, hypertension, and DIABETES further
increase the risk for atherosclerosis. Cigarette
smoking and hypertension alter the cells of the
arterial walls in ways that reduce their FLEXIBILITY,
making them more susceptible to atherosclerotic
accumulations. Diabetes and obesity both alter
lipid METABOLISM. Preventive measures include a
diet with fewer than 10 percent of its CALORIES
from saturated fats (such as meats), daily physical
exercise, SMOKING CESSATION, and WEIGHT LOSS AND
WEIGHT MANAGEMENT. Health experts encourage
people to develop heart-healthy lifestyle habits
early in life, as so much research now confirms
that the cardiovascular diseases common in people
who are in their 60s and beyond get their start in
the teenage years or earlier.
See also CALORIE; CARDIOVASCULAR DISEASE PREVEN-
TION; DIET AND HEALTH; EXERCISE AND HEALTH; LIFESTYLE
AND CARDIOVASCULAR HEALTH; PHYSICAL EXERCISE AND
CARDIOVASCULAR HEALTH; PULMONARY EMBOLISM.
atherosclerotic plaque Debris that collects
within the inner layer of the wall of an artery, also
called arterial plaque. Atherosclerotic plaque typically
includes fatty acids, dead cells, platelets, and
other particles such as proteins and minerals
(notably calcium, which gives the plaque its stiffness).
The fatty acids, such as cholesterol and
triglycerides, are heavy and sticky. The flow of the
BLOOD pushes them to the outer edges, up against
the arterial walls. Initially the debris is a minor
irritation to the inner surface of the arteries. Over
time, however, the irritation creates INFLAMMATION
that attracts further debris. The sticky nature of
the debris in combination with the inflammation
establishes a circumstance in which the debris
becomes embedded within the intima, the inner
layer of the arterial wall, creating deposits called
atheromas and evolving into the disease state of
ATHEROSCLEROSIS. Atherosclerotic plaque in the
CORONARY ARTERIES becomes CORONARY ARTERY DIS-
EASE (CAD) and in other arteries becomes PERIPH-
ERAL VASCULAR DISEASE (PVD).
See also CAROTID STENOSIS; CHOLESTEROL BLOOD
LEVELS; HYPERLIPIDEMIA; LIFESTYLE AND CARDIOVASCU-
LAR HEALTH; PLATELET; TRIGLYCERIDE BLOOD LEVEL.
atrial fibrillation An ARRHYTHMIA in which the
upper chambers of the HEART, the atria, contract
rapidly and out of synchronization with each
other. As a consequence, they do not pump BLOOD
very effectively to the ventricles. Though most of
the blood that enters the atria drains to the ventricles,
some blood pools in the atria. The pooled
blood establishes a very high risk for blood clots to
form and a corresponding increase in the risk of
STROKE or TRANSIENT ISCHEMIC ATTACK (TIA). Atrial
fibrillation is the cause of one in five strokes.
Atrial fibrillation is the most common arrhythmia
that requires treatment, affecting about 5 percent
of people over age 65.
The typical symptoms of atrial fibrillation
include
• PALPITATIONS
• rapid tiring during physical activity
• generalized fatigue
• DYSPNEA (shortness of breath)
• ANGINA PECTORIS (CHEST PAIN)
• SYNCOPE (fainting)
However, many people have mild or no symptoms,
with the doctor detecting atrial fibrillation
during the course of examination for other health
concerns.
HYPOTENSION (low BLOOD PRESSURE) and a weak,
irregular, and often rapid PULSE are common signs