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Diagnostic Testing (HS)

Arrhythmia Surveillance Program

This service provides 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.

Cardiovascular Imaging

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. The 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 the 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 before birth.

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 an 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).

Electrophysiology Study

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.

Intravascular Ultrasound

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), screen term and pre-term infants for periodic breathing as well as other disorders.

Pulmonary Angiogram

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.

Stress Testing

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 artery disease).

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 discomfort.


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 909.865.9858.