Diagnostic Testing (HS)
Arrhythmia Surveillance Program
This service provides transtelephonic and clinic monitoring of Electrocardiogram
rhythm strips in patients with transient cardiac related symptoms. This
small monitor is worn conveniently by the patient for approximately 30
days and has the capabilities of “capturing” events while
they are happening. These events are in turn forwarded to the cardiologist
for review. Diagnosis and treatment options can then be provided to the patient.
X-rays are a form of radiation, like light or radio waves that can be focused
into a beam, much like a flashlight beam. Unlike a beam of light, however,
X-rays can pass through most objects, including the human body.
When X-rays strike a piece of photographic film, they can produce a picture.
Dense tissues in the body, such as bones, block (absorb) many of the X-rays
and appear white on an X-ray picture. Less dense tissues, such as muscles
and organs, block fewer of the X-rays (more of the X-rays pass through)
and appear in shades of gray. X-rays that pass only through air appear
black on an X-ray picture.
CT or CAT scan
A computed tomography (CT) scan uses X-rays to make detailed pictures of
structures inside of the body.
During the test, you will lie on a table that is hooked to the CT scanner,
which is a large doughnut-shaped machine. The CT scanner sends X-ray pulses
through the body. Each pulse lasts less than a second and takes a picture
of a thin slice of the organ or area being studied. One part of the scanning
machine can tilt to take pictures from different positions. The pictures
are saved on a computer.
A CT scan can be used to study any body organ, such as the liver, pancreas,
intestines, kidneys, adrenal glands, lungs, and heart. It also can study
blood vessels, bones, and the spinal cord.
An iodine dye (contrast material) is often used to make structures and
organs easier to see on the CT pictures. The dye may be used to check
blood flow, find tumors, and look for other problems. Dye can be put in
a vein (IV) in your arm, or you may drink the dye for some tests. CT pictures
may be taken before and after the dye is used.
An echocardiogram (echo or echocardiogram) is a type of ultrasound test
that uses high-pitched sound waves to produce an image of the heart. The
sound waves are sent through a device called a transducer and are reflected
off the various structures of the heart. These echoes are converted into
pictures of the heart that can be seen on a video monitor.
An echocardiogram generally is used to evaluate heart wall thickness and
motion, as well as the structure and function of the heart valves. An
echocardiogram can also be used to estimate the amount of blood pumped
out of your left ventricle with each heartbeat (ejection fraction).
An echocardiogram can help identify areas of poor blood flow in the heart,
areas of heart muscle that are not contracting normally, previous injury
to the heart muscle caused by impaired blood flow, or evidence of heart
failure, especially in people with chest pain or a possible heart attack.
In addition, an echocardiogram can detect a blood clot in the heart, evaluate
the heart valves for abnormalities, and identify pericardial effusion.
A fetal echocardiogram can be used to detect congenital heart defects
There are different types of echocardiograms. A Transthoracic echocardiogram
(TTE) is the standard, most commonly used method of echocardiogram. Views
of the heart are obtained by moving the transducer to different locations
on the chest or abdominal wall. An Echo can be used as part of a stress
test and in combination with electrocardiogram (EKG) monitoring to help
your health professional gain additional information about your heart.
Electrocardiography (EKG, ECG) Tracing
Electrocardiography (EKG, ECG) tracings show a characteristic pattern of
electrical impulses that are generated by the heart. These electrical
signals control the rhythm of your heartbeat. A natural electrical system
causes the heart muscle to contract and pump blood through the heart to
the lungs and the rest of the body. The electrical activity of the heart
can be detected through the skin by small metal discs called electrodes.
During an electrocardiogram, the electrodes are attached to the skin on
the chest, arms, and legs. The electrodes are also connected to a machine
that translates the electrical activity into line tracings on paper.
These tracings are often analyzed by the machine and then carefully reviewed
by a doctor for abnormalities. An electrocardiogram may show:
- Evidence of heart enlargement.
- Signs of insufficient blood flow to the heart.
- Signs of a new or previous injury to the heart (heart attack).
- Heart rhythm problems (arrhythmias).
- Changes in the electrical activity of the heart caused by an electrolyte
imbalance in the body.
- Signs of inflammation of the sac surrounding the heart (pericarditis).
An EP Study is the monitoring and recording of the electrical activity
the heart. This test is used to help find out the cause of your rhythm
disturbance and the best treatment option for you. During the test, the
doctor may safely reproduce your arrhythmia to diagnose your specific
type and locate the site of origin of the abnormal heart rhythm.
In most cases, EP testing and the Radio-frequency therapy performed during
the same setting can cure the arrhythmia. The procedure takes approximately
two to four hours to complete.
Through the use of intravascular coronary ultrasound (IVUS) it is now possible
to thread a tiny ultrasound "camera" into the coronary arteries
to give a valuable cross-sectional view from the inside-out, showing the
physician where the normal artery wall ends and the plaque begins. In
certain situations, IVUS can assist in the selection and sizing of stents
and balloons and can help to verify that a stent has been properly deployed.
This is of increasing importance in the era of drug-eluting stents.
Traditionally, coronary angiography has and still is being used to identify
narrowing of the coronary arteries. IVUS, an expansion of traditional
angiography, shows a more detailed depiction of the type and levels of
plaque. This has proven to be useful in selecting the form of angioplasty
that would be most effective.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging (MRI) is a test that uses a magnetic field and
pulses of radio wave energy to make pictures of organs and structures
inside the body. In many cases MRI gives information that cannot be seen
on an X-ray, ultrasound, or computed tomography (CT) scan.
For an MRI test, the area of the body being studied is placed inside a
special machine that is a strong magnet. Information from an MRI can be
saved and stored on a computer for more study. Photographs or films of
certain views can also be made. In some cases, a dye (contrast material)
may be used during the MRI to show pictures of organs or structures more clearly.
MRI can be used to find problems such as bleeding, tumors, infection, blockage,
or injury in the brain, organs and glands, blood vessels, and joints.
A pneumogram procedure is a four-channel recording that provides objective
documentation of respiratory disturbance events, heart rate fluctuations,
and oxygen desaturations. Typically performed in the Neonatal Intensive
Care Unit (NICU), pneumograms screen term and pre-term infants for periodic
breathing as well as other disorders.
An angiogram of the lung is an X-ray test that uses fluoroscopy to take
pictures of the blood flow within the blood vessels of the lung. A thin
flexible tube called a catheter is usually placed into a blood vessel
in the groin or just above the elbow and guided through the heart to the
lungs. Then a dye (contrast material) that contains iodine is injected
into the vessel being studied to make it more visible on the X-ray pictures.
Lung (pulmonary) angiogram is used to evaluate the arteries that lead to
the lungs (pulmonary arteries) and the blood vessels within the lungs.
It can also detect narrowing or a blockage in a blood vessel that slows
or prevents blood flow. Angiogram pictures can be produced on regular
X-ray films or stored as digital images in a computer.
Adenosine Stress Test. Adenosine has been proven to be a very accurate
and safe method of obtaining information. The effect of adenosine on blood
vessels can allow for the detection of blockages in the heart’s
blood vessels when combined with nuclear images of the heart muscle obtained
before and after the adenosine is given.
Dobutamine Stress Test. This is a test that combines an ultrasound study
of the heart with a pharmacological stress test. It looks at how the heart
functions when it is made to work harder. A stress test usually involves
exercising, either on a treadmill or stationary bike. For patients who
are unable to exercise adequately, the test may be performed with a drug
called Dobutamine. Dobutamine has an effect on the heart similar to exercise.
Nuclear Stress Testing. Nuclear testing involves the injection of a radioactive
isotope through an IV. The isotope travels in the bloodstream and through
the coronary arteries until it is picked up by the heart muscle cells.
The areas of the heart that have an adequate blood supply pick up the
tracer right away and more completely. Areas that do not have adequate
blood supply pick up the tracer very slowly or not at all. A computer
processes the information and produces the images of the radioactivity
distributed in the heart. These images allow the doctor to compare the
amount of blood flowing through the heart muscle during stress and at rest.
Exercise Stress Test. An exercise stress test, sometimes called a treadmill
test, can help your doctor find out how well your heart handles work.
As your body works harder during the test, it requires more oxygen, so
the heart must pump more blood. The test can show if the blood supply
is reduced in the arteries that supply the heart. Blood supply levels
can also indicate coronary artery disease, a possible heart-related cause
of symptoms such as chest pain, shortness of breath or lightheadedness,
to check the effectiveness of past procedures, and to help predict the
risk of a heart attack. The stress test results also help doctors know
the kind and level of exercise appropriate for a patient. Depending on
the results of the exercise stress test, the physician may recommend more
tests such as a nuclear stress test or cardiac catheterization.
Stress Echocardiogram. This test involves a transthoracic echocardiogram
both before and after your heart is stressed either by having you exercise
or by injecting a medication (dobutamine) that makes your heart beat harder
and faster. A stress echocardiogram is usually done to determine whether
you may have a significantly reduced flow of blood to your heart (coronary
Transesophageal Echocardiogram (TEE)
For a Transesophageal Echocardiogram (TEE), the transducer is passed down
the esophagus instead of being moved over the outside of the chest wall.
TEE shows clearer pictures of your heart, because the transducer is located
closer to the heart and because the lungs and bones of the chest wall
do not interfere with the sound waves produced by the transducer. This
test requires a sedative and an anesthetic applied to the throat to ease
Ultrasound is a test that uses reflected sound waves to produce an image
of organs and other structures in the body. It does not use X-rays or
other types of possibly harmful radiation.
For ultrasound testing, gel or oil is applied to the skin to help transmit
the sound waves. A small, hand held instrument called a transducer is
passed back and forth over the area of the body being examined. The transducer
sends out high-pitched sound waves (above the range of human hearing)
that are reflected back to the transducer. A computer analyzes the sound
waves and converts them into a picture that is displayed on a TV screen.
The picture produced by ultrasound is called a sonogram, echogram, or
ultrasound scan. Pictures or videos of the ultrasound images may be made
for a permanent record.
For more information on Pomona Valley Hospital Medical Center's Stead
Heart & Vascular Center, please call