Diagnostic Procedures

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To diagnose why you are experiencing irregular heartbeats, your doctor will likely begin with a physical exam and a discussion of your medical history.

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During the discussion, your doctor will want to know about your symptoms, when they began, how often you have symptoms, how long they last and what they feel like. Be sure to share any history of heart or lung problems, high blood pressure or thyroid dysfunction as these conditions can trigger arrhythmias.

The heart's pumping action is driven by electrical stimulation within the heart muscle. The heart's electrical system allows it to beat in an organized pattern. Electrical signals in your heart can become blocked or irregular, causing a disruption in your heart's normal rhythm. When the heart rhythm is too fast, too slow, or out of order, arrhythmia—also called a rhythm disorder—occurs. When your heart beats out of rhythm, it may not deliver enough blood to your body.

Your doctor may order one or more of the following diagnostic tests to learn more about your heart's electrical system and if blood is moving through your heart and lungs as it should.

Electrocardiogram (ECG) – The ECG is used to gather a record of the heart's electrical activity, including any abnormal electrical impulses. The test is given at the doctor's office. During an ECG, electrodes are placed on your wrists, ankles and chest to monitor your heart rhythm, which is recorded on graph paper.  

Holter Monitor – A Holter monitor is a portable ECG that can be worn for a day or more to automatically record your heart's activity. It is used to show a change in heart rhythm over time while you go about daily activities.

Event Recorder – An external recorder is a portable ECG that is worn on your body to monitor your heart rhythm at home. Unlike a Holter monitor, it doesn't record continuously. When you feel symptoms, you push a button and a recording is made.

Electrophysiologic Testing or EP Study – An EP study makes it possible to reproduce troubling arrhythmias in a safe setting and learn where in the heart they begin.

During an EP study, a thin tube (called a diagnostic catheter) is inserted into a blood vessel and moved through your body and into your heart. An electrophysiologist, a cardiologist with training in heart rhythm disorders, watches on a special monitor as the catheter is moved into place.

Once inside the heart, the catheter stimulates your heart and records where irregular electrical signals start, how fast they travel and how they affect your heart rhythm. During the test, your doctor may choose to treat your arrhythmia to learn if a certain treatment stops the arrhythmia. After the testing is done, the catheter is removed and the insertion site is closed with stitches or by applying pressure at the site.

Learn more about the types of doctors who may be involved in your care.

Tilt Table Test – A tilt table test is used to explain lightheadedness or fainting. You begin by lying flat on a table. Then, the table is lifted to raise the upper part of your body, as if you were standing. Your doctor studies how your heart responds to the change in position by monitoring your blood pressure, heart rate and heart rhythm.

Stress Test – This test records your heart’s electrical activity while you walk on a treadmill or pedal on an exercise bike. While you exercise, heart rate is monitored. If you are unable to use the treadmill or stationary bike, your doctor may create the effect of exercise on your heart with a medication.

Last Reviewed: March 11, 2010 900245