Risks and Complications
There are no risks or complications associated
with ECG. Sometimes the ECG technician must
shave a small area of SKINto allow good electrode
contact. Some people who are highly sensitive to
adhesive may have a slight skin reaction to the
adhesive pad that holds the electrode in place.
And some people quickly chill when lying on the
procedure table; the ECG technician can cover the
person with a warm blanket for improved comfort
and to prevent shivering, which can distort the
ECG reading. ECG only detects and records the
electrical activity of the heart; it does not send any
electrical impulses to the heart.
See also AUTOMATED EXTERNAL DEFIBRILLATOR
(AED); CARDIOVERSION; DEFIBRILLATION; ECHOCARDIO-
GRAM.
electrophysiology study (EPS) A diagnostic pro-
cedure in which the cardiologist inserts electrodes
into the HEARTto measure the heart’s rhythm and
response to various stimuli. The EPS is similar to
CARDIAC CATHETERIZATIONand provides information
to help diagnose disorders of ARRHYTHMIA. The EPS
takes place in a hospital or cardiac catheterization
laboratory setting and is a same-day procedure for
most people. Preparation consists of no food or
drink the night before the procedure. The person
undergoing the EPS needs a family member or
friend to drive to and from the hospital.
After administering a general sedative and a
local anesthetic, the cardiologist threads several
catheters through an incision in the groin into the
femoral vein and then through the arterial net-
work to the heart, watching their progress via
FLUOROSCOPY. Once in the heart, the leads on the
tips of the catheters send back electrical impulses
similar to an ELECTROCARDIOGRAM(ECG). The cardi-
ologist may administer medications or mild elec-
trical impulses to assess the heart’s response and
ability to return to a normal rhythm.
An EPS takes three to four hours to complete.
After the procedure is over, the person goes to a
recovery area until he or she is fully awake from
the sedative and the cardiologist is satisfied there
will be no adverse effects. Sometimes the cardiolo-
gist will want the person to stay overnight in the
hospital for cardiovascular monitoring. Most peo-
ple experience mild to moderate discomfort in the
groin area where the cardiologist inserted the
catheters, and occasionally this is the site for post-
procedure bleeding. The EPS provides comprehen-
sive information about the heart’s electrical
activity.
See also ECHOCARDIOGRAM; STRESS TEST.endarterectomy An OPERATION to surgically
remove accumulations of ATHEROSCLEROTIC PLAQUE
(atheromas) from the arteries. The most common
site for endarterectomy is the carotid arteries,
which carry BLOOD to the head and BRAIN.
Endarterectomy is a major surgery done under
general ANESTHESIA, typically with 24 to 48 hours
of inpatient hospitalization following the OPERA-
TION. During endarterectomy, the surgeon makes a
small incision through the SKINand into the ARTERY
at the site of the atheroma, briefly stops the flow
of blood through the artery and removes the
atheroma, restores blood flow, and sutures the
artery closed. Depending on the location and size
of the atheroma the surgeon may place a shunt in
the artery to allow blood to flow around the site of
the atheroma during the operation. The shunt
maintains blood supply to the brain and helps pre-
vent atherosclerotic fragments from escaping into
the blood flow to the brain.
Endarterectomy is a fairly high risk procedure
because of the potential for dislodging fragments
of the atheroma during the procedure. When this
happens, there is no way to prevent the fragments
from traveling up the carotid artery to the brain
where they cause STROKE. About 3 percent of peo-
ple who undergo endarterectomy experience
stroke, ranging in severity from imperceptible
symptoms to disability or death. Cardiologists rec-
ommend endarterectomy when the occlusion is
80 to 99 percent. Studies show that endarterec-
tomy can lower the risk for stroke even when
CAROTID STENOSISdoes not cause symptoms, though
because of the risk that the operation itself can
result in stroke, some cardiologists recommend
surgery only when the blockage causes symptoms.
See also CORONARY ARTERY BYPASS GRAFT(CABG);
POSTOPERATIVE PROCEDURES; PREOPERATIVE PROCEDURES;
SURGERY BENEFIT AND RISK ASSESSMENT.endocarditis INFLAMMATIONof the ENDOCARDIUM,
the lining of the HEART. Viral or bacterial INFECTIONendocarditis 53