Tests and diagnosisBy Mayo Clinic staff
Your doctor can make a diagnosis of a specific tachycardia based on your answers to questions about symptoms, a physical exam and heart tests. Common tests include the following.
An electrocardiogram — also called an ECG or EKG — is a primary tool for diagnosing tachycardia. An ECG uses small sensors (electrodes) attached to your chest and arms to record electrical signals as they travel through your heart. Your doctor can look for patterns among these signals to determine what kind of tachycardia you have and how abnormalities in the heart may be contributing to a fast heart rate.
Your doctor may also ask you to use portable ECG devices at home to provide more information about your heart rate. These devices include:
- Holter monitor. This portable ECG device is carried in your pocket or worn on a belt or shoulder strap. It records your heart's activity for an entire 24-hour period, which provides your doctor with a prolonged look at your heart rhythms. Your doctor will likely ask you to keep a diary during the same 24 hours. You'll describe any symptoms you experience and record the time they occur.
- Event recorder. This portable ECG device is intended to monitor your heart activity over a few weeks to a few months. You activate it only when you experience symptoms of a fast heart rate. When you feel symptoms, you push a button, and an ECG strip of the preceding few minutes and following few minutes is recorded. This permits your doctor to determine your heart rhythm at the time of your symptoms.
Your doctor may recommend an electrophysiological test to confirm the diagnosis or to pinpoint the location of problems in your heart's circuitry. During this test, thin, flexible tubes (catheters) tipped with electrodes are threaded through your blood vessels to various spots in your heart. Once in place, the electrodes can precisely map the spread of electrical impulses during each beat and identify abnormalities in your circuitry.
Tilt table test
This test helps your doctor better understand how your tachycardia contributes to fainting spells. Under careful monitoring, you'll receive a medication that causes a tachycardia episode. You lie flat on a special table, and then the table is tilted as if you were standing up. Your doctor observes how your heart and nervous system respond to these changes in position.
Your cardiologist may order additional tests to diagnose an underlying condition that is contributing to tachycardia and judge the condition of your heart.
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