CARDIAC CATHETeRIZATION
This procedure allows for a comprehensive assessment of the heart
and the blood vessels that supply the heart muscle. Special catheters
are threaded to the heart via major blood vessels in the arm or
the leg. A dye is injected via the catheter and x-ray equipment
especially designed for this purpose records images of the dye
flow through the heart and the blood vessels. Various pressures
within the heart are measured thus indicating the effectiveness
of the heart’s pumping ability and valve function.
Intracoronary Ultrasound
This diagnostic evaluation tool is done during cardiac catheterization
when the physician desires the benefits of ultrasound images of
the interior walls and structure of the coronary arteries. In this
case, a special coronary artery catheter with a transducer
(a sound wave-producing device) is guided into the major heart
arteries, and utilizing the ultrasound technology, graphic images
of the artery walls are reproduced. These images can detect structural
abnormalities within the arteries as well as further clarify the
extent of an artery blockage.
Echocardiography
This is a noninvasive ultrasound procedure that uses sound waves
and computerized digital equipment to provide graphic images of
the heart, its valves, and its chambers. These images are then
examined by the physician to detect abnormalities of the heart
anatomy or compromised function of the valves and chambers. This
study is called a transthoracic echocardiogram because the sound
waves pass through the chest wall to achieve the resulting images.
Transesophageal Echocardiogram (TEE)
In some instances, your physician may request this type of echocardiogram
in order to gain even clearer images of the heart. This study involves
placement of a transducer within a special tube that is passed
down the esophagus or food tube. Because the transducer is positioned
immediately adjacent to the heart, the sound waves can be utilized
to obtain more defined images because they do not have to pass
through the lungs or chest wall. This study is especially helpful
in assessing the presence of clots, masses, or tumors within the
heart. It is also used to clarify heart valve function and the possibility of
infection of the heart valves. Furthermore, images of the aorta
taken during the study can locate a tear or dissection of this
major vessel. Accomplished under minor sedation, TEE (transesophageal
echocardiogram) is usually done as an outpatient procedure.
Electrocardiographic Tests (ECG or EKG) These tests take advantage of the fact that every time the heart
beats, electrical impulses are produced. Electrodes with pads are
attached to the patient in order to record the pattern of electrical
activity generated. The resulting electrocardiogram (ECG or EKG)
generates important information about the status of the heart.
By analyzing the shape and size of the wave recording, the rate
and pattern of occurrence as well as the time lapse in-between,
the physician can diagnose a heart arrhythmia (abnormal heartbeat),
determine that not enough blood is reaching the heart muscle, or
establish that the heart chambers may be enlarged.
Stress Testing
Lack of blood supply to the heart reveals itself more readily
when the heart is stressed such as during vigorous exercise. This
is why exercising on a treadmill and recording the heart’s
electrical activity may be ordered to assess the possible presence
of artery blockage. This is also known as a stress ECG or simply
as a treadmill test. A treadmill
or stationary bicycle with cardiac monitoring is frequently used
to exercise patients in
a gradual controlled fashion for a variety of reasons. Some of
the indications include screening for the presence of coronary
artery disease, attempting to produce an arrhythmia, or determining
the effectiveness of medications in the presence of physical activity.
Nuclear Imaging
This diagnostic tool, usually in combination with stress testing,
utilizes low-dose radioactive isotopes that are injected and then
traced through the circulatory system of the heart. Thallium and
Cardiolyte are two commonly used isotopes in cardiac nuclear imaging.
After injection of the isotopes, a special camera records the progression
of the circulating isotopes and the resulting images of the heart.
These recorded images are assessed for the possibility of blockages
within the coronary arteries. In cases where patients are physically
unable to exercise, the administration of an intravenous medication
simulates the heart’s response to the stress of exercise.
MRI (Magnetic Resonance Imaging)
This imaging technique involves the use of magnets and radiofrequency
waves. The
images produced provide information about the status of the heart
muscle as well as
the structure and functional capabilities.
Electrophysiology Studies
For the patient, the perception of the electrophysiology study
is very similar to the performance of cardiac catheterization.
The electrophysiology study is performed in the cardiac cath lab
to determine the existence and nature of an arrhythmia or abnormal
heartbeat. For this evaluation of the heart’s electrical
system, special electrode catheters are introduced via the peripheral
circulatory system to the heart where they are used to study the
pattern of electrical impulses being generated. This study actually
creates a map if the electrical activity and identifies the location
of the abnormality in order to decide what intervention or treatment
is in the best interest of the patient.
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