Encyclopedia of Health and Medicine

E–G
echocardiogram A noninvasive, diagnostic
ULTRASOUND examination of the HEART that can
show the heart’s structure and, when combined
with Doppler technology, the flow of BLOOD
through the heart’s chambers and the CORONARY
ARTERIES. Echocardiogram is most effective for
evaluating VALVULAR HEART DISEASE and structural
malformations of the heart such as major congenital
deformities, septal defects, and patent ductus
arteriosus (PDA).
There is no preparation for a echocardiogram,
which uses soundwaves to create visual images.
For a transthoracic echocardiogram (TTE), the
ultrasonographer places a small amount of gel on
the SKIN of the chest to improve contact with the
transducer, the device that sends and receives the
sound signals. The ultrasonographer then moves
the transducer over the surface of the skin. For a
transesophageal echocardiogram (TEE), the ultrasonographer
numbs the back of the THROAT and
passes a narrow cable with a transducer at the tip
down the throat into the ESOPHAGUS. A TEE places
the transducer as close as possible to the heart,
usually to obtain specific images such as to detect
septal defects or certain valve malformations.
A computer converts the sound signals into
two- or three-dimensional images. Typically the
cardiologist does an ELECTROCARDIOGRAM (ECG) at
the same time, to correlate the visual images from
the echocardiogram with the heart’s electrical
activity. Sometimes the cardiologist will combine
the echocardiogram with an injection of dye,
administered intravenously, to better highlight the
inner structures of the heart. Echocardiogram or
TTE takes 10 to 20 minutes and there is no recovery
time necessary after the procedure. People
undergoing TEE generally receive sedation before
the procedure begins so go to a recovery area after
51
the TEE until fully awake from the sedative and
the cardiologist is satisfied there will be no adverse
effects.
CONDITIONS ECHOCARDIOGRAM CAN HELP
DIAGNOSE OR MONITOR
AMYLOIDOSIS
aortic ANEURYSM
AORTIC STENOSIS
CARDIAC TAMPONADE
CARDIOMYOPATHY
congenital heart malformations
ENDOCARDITIS
HEART FAILURE
HEMACHROMATOSIS mitral valve prolapse
MYOCARDIAL INFARCTION MYOCARDITIS
MYXOMA
patent ductus arteriosus
PERICARDITIS
PRIMARY PULMONARY HYPERTENSION
septal defect
VALVULAR HEART DISEASE
See also ANGIOGRAM; COMPUTED TOMOGRAPHY (CT)
SCAN; CONGENITAL HEART DISEASE; MAGNETIC RESO-
NANCE IMAGING (MRI).
ectopic beat An extra or additional heartbeat.
Ectopic beats can be atrial, called premature atrial
contractions (PACs), or ventricular, called premature
ventricular contractions (PVCs). PACs are
nearly always benign (do not require treatment).
Though most PVCs are also benign, persistent
PVCs can cause symptoms that do require treatment.
CAFFEINE is a common cause of ectopic
beats. ALCOHOL use, cigarette smoking, and illicit
drugs also can cause or exacerbate ectopic beats.
The most common symptom of ectopic beat is
PALPITATIONS, the perception of the heart jumping
or skipping a beat though it actually does neither.
Ectopic beats are premature—that is, they are normal
contractions that occur before their normal
rhythm in the CARDIAC CYCLE. The beat that follows,
also a normal beat, then feels intensified. An
ELECTROCARDIOGRAM (ECG) shows the heart’s electri-