slip through filtration can cause damage to the
BRAINand lungs. Some people experience neuro-
logic effects such as cognitive dysfunction, mem-
ory difficulties, and mood swings in the months
after cardiopulmonary bypass. Cardiopulmonary
bypass also can affect lung function. However, for
most people the benefit of the operation car-
diopulmonary bypass makes possible outweighs
the potential risk for these usually transitory side
effects. Cardiovascular surgeons continue to
explore new techniques that reduce or eliminate
the need for cardiopulmonary bypass, including
MINIMALLY INVASIVE SURGERY and off-pump proce-
dures though these, too, carry risks.
See also CONGENITAL HEART DISEASE; SURGERY BENE-
FIT AND RISK ASSESSMENT.
cardiovascular disease (CVD) The collective
term for the numerous health conditions of the
HEART and BLOODvessels. Cardiovascular disease
(CVD) is the leading cause of death and disability
in the United States and in many other developed
countries. More than 70 million Americans live
with CVD; 10 million of them have sufficient dis-
ability that they cannot work or participate in the
activities they enjoy. CVD claims over 900,000
lives each year. The most common forms of CVD
are HYPERTENSION(high BLOOD PRESSURE), ATHERO-
SCLEROSIS(occluded arteries), CORONARY ARTERY DIS-
EASE (CAD), and ISCHEMIC HEART DISEASE (IHD).
Health experts sometimes refer to CAD and IHD
collectively as coronary heart disease (CHD).
Most CVD develops as a consequence of
lifestyle factors, though age, gender, and genetic
predisposition also contribute. The primary risk
factors for CVD are
- cigarette smoking
- OBESITY
- physical inactivity
- DIABETES
- renal (kidney) disease
- being a man under age 50
- age over 50 for men and over 60 for women
- family history of CVD
Acquired CVD is largely preventable through
lifestyle practices that incorporate nutritious eat-
ing habits, daily physical exercise, and not smok-
ing. These practices are also preventive for health
conditions that lead to CVD, such as diabetes and
obesity. Other forms of CVD may be hereditary or
congenital. Hereditary CVD conditions are the
result of GENEmutations. CONGENITAL HEART DISEASE
results from structural defects in the heart and its
major vessels, such as tetralogy of Fallot, or to
blood vessels elsewhere in the body, such as ARTE-
RIOVENOUS MALFORMATION(AV M), that occur during
early gestational development and are present at
birth.
For further discussion of CVD please see the
overview section “The Cardiovascular System.”
See also AGING, CARDIOVASCULAR CHANGES THAT
OCCUR WITH; LIFESTYLE AND CARDIOVASCULAR HEALTH;
PREVENTING CARDIOVASCULAR DISEASE; SMOKING AND
CARDIOVASCULAR DISEASE.cardioversion The application of an electrical
shock through the chest wall to the HEART,
administered under sedation, to alter the heart’s
electrical rhythm. The cardiologist performs car-
dioversion in a hospital setting staffed and
equipped to respond to cardiovascular emergen-
cies. There is a slight risk for HEART ATTACK or
STROKE. Cardioversion is most commonly a treat-
ment for ARRHYTHMIAsuch as ATRIAL FIBRILLATION, in
which the heart’s electrical patterns have gotten
out of synchronization in some way. The effect
may be permanent, long-lasting, or short term.
Some people experience slight SKINirritation at
the site of the electrodes or paddles on the surface
of the chest following cardioversion. Because the
procedure requires a general sedative, there may
also be grogginess for several hours. Most people
go home within 4 to 6 hours and return to their
usual activities the following day.
See also DEFIBRILLATION; IMPLANTABLE CONVERTER
DEFIBRILLATOR(ICD); RADIOFREQUENCY ABLATION.carotid bruit An abnormal sound characteristic
of ATHEROSCLEROSIS that the cardiologist hears
through a STETHOSCOPE placed over the carotid
ARTERYat the base of the neck. The sound, a mur-
mur that occurs during systole (contraction of the
left ventricle), represents turbulence as BLOOD
passes through areas of the carotid artery where
atheromas (collections of ATHEROSCLEROTIC PLAQUE)34 The Cardiovascular System