Diagnostic Testing
Although the history and physical examination remain key tools in diagnosing heart conditions and assessing the reponse to treatment, it is often necessary to perform specialized diagnostic tests to obtain more detailed and accurate information. Often this is a source of questions and anxiety for patients. Although it is the responsibility of your physician or provider to explain the rationalle for such tests, alternative diagnostic methods, and any risks involved, it is not uncommon for the average patient to have remaining questions. We hope, here, to provide you with additional information about commonly performed diagnostic cardiac tests at DHMC and to make the process just a little bit less anxiety inducing!
Some of the tests we use often in the DHMC Cardiology department:
| Echocardiogram |
Heart Catheterization | |||
| Dobutamine Stress Echocardiogram | Holter Monitor | |||
| Exercise Echocardiogram | Loop Recorder | |||
| Transesophageal Echocardiogram | Implantable Loop Recorder | |||
| Transthoracic Echocardiogram | Stress Tests | |||
| Endomyocardial Biopsy | Treadmill Stress Test | |||
| Electrocardiogram (ECG or EKG) | Sestamibi Stress Test | |||
| Signal Average ECG | Adenosine Sestamibi Stress Test | |||
| Electrophysiologic Study | T-wave Alternans Stress Test | |||
| Event Monitor | Tilt Table Testing | |||
Echocardiogram
An echocardiogram uses sound waves to make a picture of your heart. Your doctor sees this image on a television monitor, and can examine how well your heart works. Doctors often use echocardiograms to tell if a person has a heart arrhythmia, or irregular heartbeat. The test takes about 45 minutes, and is painless.
An exercise echocardiogram shows how well your heart works before and after exercise. Your doctor first takes an echocardiogram, then has you walk on a treadmill or ride an exercise bike until your heart reaches a certain rate. He or she then takes a second reading, and compares the results.
Dobutamine Stress Echocardiogram
This is for patients who are too weak to do an exercise echocardiogram. The drug dobutamine makes the heart speed up, as if you had been exercising.
Transesophageal Echocardiogram
An esophageal echocardiogram uses a thin, soft, flexible plastic tube to take an echocardiogram close to your heart's upper (atrial) chambers. The tube is inserted into your nostril and guided to the esophagus, the tube that connects the mouth and stomach. A recording here gives more precise information than a regular echocardiogram.
During a transthoracic (through-the-chest) echocardiogram, the sound-wave producing equipment (transducer) is moved over the skin of your chest to make images of the front and sides of your heart.
Endomyocardial Biopsy
A doctor uses a thin, flexible tube (catheter) with a tiny grasping device on its tip to take a small piece of heart muscle tissue. The tissue—about the size of the head of a pin—is then tested. Endomyocardial biopsy is used after a heart transplant, to see if the heart has been accepted or rejected by the body, and also to diagnose cardiomyopathy. The procedure takes about an hour.
Electrocardiogram (ECG or EKG)
An electrocardiogram (ECG or EKG) measures the electrical activity of your heart. It helps your doctor see how well your heart beats, and can tell if your heart muscle has been damaged in any way. A technician puts small metal disks—electrodes—on your skin to read the pattern of electrical impulses from your heart. The test only takes a few minutes, and is often used to diagnose a heart arrhythmia, or irregular heartbeat.
This is also called a high-resolution ECG. It uses three different waves of electrical signals to measure different parts of your heartbeat. The test may tell if you are at risk for dangerous arrhythmia, or irregular heartbeats, in the lower portion of your heart.
Electrophysiologic Study
An electrophysiology study (EPS) shows how your heart reacts to electrical signals. It is used to diagnose heart arrhythmia, or irregular heartbeats. You will be awake, but under mild pain medicine, for the procedure. Your doctor first threads a thin, flexible tube—a catheter—from an artery in your leg up into your heart. He or she then uses small electrical impulses to make your heart beat at different speeds. This helps your doctor learn where the arrhythmia starts, and which medicines might help stop your heart's irregular rhythm. You will need to rest in the hospital for a few hours after an electrophysiology study.
Event Monitor
Irregular heartbeats, or arrhythmia, sometimes pass before a patient can reach thedoctor or hospital. Because a doctor needs to study every patient's arrhythmia symptoms, he or she may give a patient a small event monitor to take home. Whenever the patient feels irregular heartbeats, he or she turns on the monitor and makes an electrocardiogram. The patient can then use the monitor to send the data by phone to the doctor for study.
Heart Catheterization
A heart catheterization allows a doctor to record information from inside the heart. With the patient awake and under pain medicine, the doctor inserts a thin, flexible tube called a catheter into an artery in the leg, and guides it into the heart. The doctor can then perform many tests, including an angiography, where an injected dye shows the heart and its arteries.
Holter Monitor
A Holter monitor provides a non-stop reading of your heart rate and rhythm as you go about your daily activities. You wear the small monitor at all times, and it makes a record of your heart's electrical activity, much like an electrocardiogram. This gives your doctor valuable information about what happens to your heart when you feel an arrhythmia (irregular hearbeat), or chest pain (angina). Holter monitors are most often used for a day or two.
A loop recorder is similar to a Holter monitor, in that it provides a reading of your heart rate and rhythm as you go about your daily activities. However, a loop recorder is used for longer periods of time than a Holter monitor. Most record your heart's rate and rhythm only when a button or switch is turned on.
An implantable loop recorder is placed just beneath the skin of your upper chest in a brief operation. It is about the size of a pack of gum, and continuously monitors the rate and rhythm of your heart. After an episode of irregular heartbeats (arrhythmia), chest pain (angina), or fainting (syncope), you can send information from the loop recorder to your doctor for study.
A stress test shows how your heart responds when it needs to pump harder. This can help your doctor diagnose several heart conditions, or learn what level of exercise your heart can safely handle.
In this common test, a patient is first hooked up to monitoring equipment, which may include an electrocardiogram, and then told to walk slowly on a treadmill. A technician adjusts the speed and angle of the treadmill to make the patient's heart work harder. Afterwards, the technician may perform an echocardiogram.
In this test, a radioactive tracer (sestamibi) shows how blood flows to your heart before, during, and after exercise. A tiny amount of sestamibi is injected while you work out on a treadmill. A special camera then records images as the sestamibi moves through your heart and arteries. Sestamibi stress tests are more accurate and provide more information than standard treadmill stress tests.
Adenosine Sestamibi Stress Test
This is for patients who are too weak to exercise. The drug adenosine makes the heart speed up, as if you had been exercising. A special camera then records images as the sestamibi moves through your heart and arteries.
T-wave Alternans Stress Testing
This test finds tiny heartbeat variations in your electrocardiogram that may lead to heart problems. You exercise on a treadmill for about ten minutes while a technician measures your heart's electrical patterns. These patterns can predict your chances of having a heart arrhythmia or a heart attack.
A tilt-table exam is sometimes given to those with a history of fainting (syncope). The test shows how a patient's heart reacts to a quick change of position. The patient lies flat on a table which is then rapidly tilted to 65 degrees. Sometime a doctor may give a patient various medications during the test to help find the best treatment for a patient's fainting episodes.
