Tachycardia

Diagnosis

Mayo Clinic doctors trained in heart rhythm disorders (electrophysiologists) work with your doctor to diagnose your condition. Your doctor may ask you whether you have been diagnosed with any conditions that can trigger your rapid heartbeat, such as coronary artery disease or a thyroid problem.

Different tests can reveal the kinds of information that help your doctor recommend the most appropriate treatment.

• Electrocardiogram (ECG). In this test, your doctor puts sensor patches with wires attached (electrodes) on your skin to measure the timing and duration of each electrical phase in your heartbeat.
• Echocardiogram. Your doctor puts a device (transducer) on your chest, and sound waves bounce off your heart and produce video images of your heart's size, structure and motion.
• Coronary angiogram. To get a detailed look inside the blood vessels of your heart, the doctor injects a dye that shows up on an X-ray and then makes a series of X-ray images.
• Blood tests. These tests help identify thyroid problems or other blood chemistry abnormalities that may lead to tachycardia.
• Stress test. To find out if exercise triggers or worsens your tachycardia, you will exercise on a treadmill or stationary bicycle while your doctor closely watches your heart activity with an electrocardiogram (ECG).
• Electrophysiology (EP) testing and mapping. This test involves threading thin, flexible tubes (catheters) with electrodes at the tips through your blood vessels into your heart to precisely map the spread of electrical impulses through your heart.

Some tests involve monitoring the heart during your everyday activities.

• Holter monitor. Your doctor may ask you to wear this portable ECG device for a day or more to record your heart's electrical activity.
• Event monitor. If your irregular heartbeats come and go from time to time, your doctor may ask you to wear a portable ECG event monitor at home that you start when symptoms occur. You may also have an implanted recorder.

Read more about blood tests, coronary angiograms, echocardiograms, electrocardiograms, Holter monitors and stress tests.