81 milligrams (mg) daily (one “baby” aspirin tablet)
or 325mg milligrams every other day (one “regu-
lar” aspirin). Some products are available at 162mg
strength, marketed specifically for aspirin therapy.
Call 911 at the first sign of HEART ATTACK.
Do not wait for an aspirin to relieve the
PAINof a heart attack. An aspirin will
only help to limit blood clotting during
the heart attack. It will not help the
pain.Aspirin may also limit the damage of a HEART
attack that is under way. Cardiologists recommend
that people who experience symptoms of heart
attack first call 911 for emergency medical aid and
then chew an aspirin tablet. Chewing the aspirin
tablet gets it into the bloodstream more quickly
than swallowing. Studies show this approach
releases enough of a burst of anticoagulant into
the blood to help prevent fibrin and other clotting
substances from adhering to the blockage in the
coronary artery that is causing the symptoms. This
small action can significantly reduce the amount
of heart tissue that suffers oxygen deprivation and
possible death during a heart attack.
See also CARDIOVASCULAR DISEASE PREVENTION;
CORONARY ARTERIES; DEEP VEIN THROMBOSIS(DVT); RISK
FACTORS FOR CARDIOVASCULAR DISEASE.
atherectomy A surgical procedure, done via
CARDIAC CATHETERIZATION, to remove patches of
arterial plaque (ATHEROSCLEROTIC PLAQUE), called
atheromas, from the inner walls of major arteries
such as the CORONARY ARTERIES. The cardiologist
uses either a laser to vaporize or a rotary burr on
the end of the catheter to shave away the athero-
mas. Often the cardiologist follows the atherec-
tomy with balloon ANGIOPLASTY and STENT
placement to help keep the ARTERY open, as
atheromas tend to redevelop. Risks of atherec-
tomy include STROKEandHEART ATTACKfrom debris
particles that break away and become lodged in
the arteries of the BRAINor the HEART.
See also ENDARTERECTOMY; SURGERY BENEFIT AND
RISK ASSESSMENT.
atherosclerosis Accumulation of lipids and other
materials (ATHEROSCLEROTIC PLAQUE) between the
two layers of an artery’s inner wall, the intima.
Over time the accumulations form brittle, hard
deposits called atheromas that thicken the intima
and the media (the middle of the arterial wall’s
three layers). The usual consequence is that the
ARTERYbecomes stiff and less flexible, and its inner
channel, the lumen, narrows. The combined effect
limits the ability of the artery to dilate or constrict,
increasing the pressure necessary to push BLOOD
through the artery. The result is CARDIOVASCULAR
DISEASE(CVD), including HYPERTENSION(high BLOOD
PRESSURE), CORONARY ARTERY DISEASE (CAD), and
PERIPHERAL VASCULAR DISEASE(PVD). Atherosclerosis
takes decades to develop. Many researchers
believe the process of atherosclerotic accumula-
tion begins in late childhood.
Atherosclerosis will most commonly affect
medium-size arteries such as the CORONARY ARTER-
IESthat supply the HEART, the carotid arteries that
supply the BRAIN, and the primary arteries that
supply the legs. Atherosclerosis can also develop
in the large arteries, notably the AORTA. Athero-
sclerosis in the aorta presents a significant risk for
aortic ANEURYSM, a potentially life-threatening cir-
cumstance in which the walls of the aorta weaken
and begin to separate. The most significant risk of
atherosclerosis, however, is HEART ATTACK or
STROKE, resulting from particles of atherosclerotic
plaque that break free and become lodged in an
artery. The blockage may occur at the location of
the occlusion or at a distant site. Blood clots also
may form at the sites of the plaque accumulations
(atheromas), occluding the artery at the site or,
like the plaque particles, breaking free and becom-
ing lodged elsewhere in the body.Symptoms and Diagnostic Path
Atherosclerosis typically does not present symp-
toms until it advances to a further disease state
such as CAD or hypertension resulting from renal
artery stenosis. A key indicator that atherosclerosis
exists, however, is elevated blood lipid (cholesterol
and triglycerides) levels. Cardiologists generally
perceive a total blood cholesterol level of 200 as
indicating that there is some degree of atheroscle-
rotic disease present. Lowering CHOLESTEROL BLOOD
LEVELSreduces the risk for further atherosclerotic
deposits and can also reverse to some extent ath-
erosclerotic disease that already exists. The diag-atherosclerosis 21