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Tests and Diagnosis

Glossary

Glossary

Find definitions of technical terms in our glossary.

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Learn about heart health and rhythm disorders, including details about additional diagnostic tests, from the American Heart Association.

Having Tests and Receiving a Diagnosis 

When you visit a doctor to discuss your arrhythmia, be prepared to talk about your symptoms, how long they last and what they feel like. The doctor will want to know your medical history, in particular about heart or lung problems, high blood pressure or thyroid dysfunction, which can cause arrhythmias. You may also receive a physical exam. The doctor will order one or more heart-monitoring tests to identify and document your arrhythmia. There are many types of heart rhythm disorders and many types of tests available to diagnose them.

Arrhythmia testing 

Common diagnostic tests for arrhythmias include:

Insertable cardiac monitors (ICMs)

An insertable cardiac monitor (ICM) provides valuable diagnostic information for your doctor to detect a variety of suspected arrhythmias. Unlike other tests, an ICM monitors your heart rhythm over a longer length of time.

St. Jude Medical is the first to introduce a technology designed to automatically transmit your heart data securely to your doctor, using a smartphone app. Our Confirm Rx™ insertable cardiac monitor gives your doctor continuous insight into your heart’s activity without disrupting your life.

Electrocardiogram (ECG or EKG)

This test is the most basic and generally takes place in your doctor’s office, where a healthcare professional places sticky electrodes on your wrists, ankles and chest for a few minutes to record your heart’s electrical activity. The test does not hurt. The timing and duration of the electrical phases of your heartbeat are recorded. The doctor studies the three waves that appear on the ECG. Each wave represents a different part of the heartbeat and tells the doctor about your heart and its rhythm. This test shows a snapshot of your heart’s electrical activity. 

Echocardiogram

This ultrasound test records sound waves in your heart using a microphone-like attachment. When administering this test and evaluating the results, your doctor can look at your heart in motion. The test can provide a wealth of helpful information, including the size and shape of your heart, its pumping capacity, and the location and extent of any tissue damage. 

Holter monitor

This device is a small portable electrocardiogram (ECG) that you wear around your neck or in a pocket to automatically record your heart's activity. It records your heart rhythm as you go about your daily activities for 24 to 48 hours, and provides your doctor with information about changes in your heart rhythm over that period of time.

Event recorder

Like a Holter monitor, this is another small, portable electrocardiogram (ECG) that you wear to monitor your heart’s rhythm. When you feel symptoms, you push a button and the device records your heart’s electrical activity. It is often used with patients who have infrequent symptoms.

Electrophysiologic testing or EP study

In an electrophysiology (EP) lab or hospital, an electrophysiologist—a doctor trained in heart rhythm disorders—inserts a catheter, a special long, flexible tube with a wire, into one of your blood vessels, moving the catheter through your body and into the heart. The doctor then uses the catheter, medication or another kind of stimulus to trigger an arrhythmia. The doctor can evaluate your type arrhythmia and determine how best to treat it. Treatment could include medication and an implanted device or some other option.

Tilt table test

This test is often used when people have fainting or near-fainting spells. If you experience these, in this test your medical team straps you comfortably to a special table that tilts upright for 30 to 45 minutes, as if you are standing, to see if you will faint. As the angle of the table changes, your heart rhythm and blood pressure are monitored to see if and how they change.

Blood test

Your doctor may conduct a blood test to rule out other conditions that may cause arrhythmias. For example, hyperthyroidism—overproduction of the thyroid hormone—and other chemical abnormalities in the blood may trigger atrial fibrillation (AF) episodes.

Stress test

Some arrhythmias are triggered or made worse by exercise. In this test, you walk on a treadmill or pedal on an exercise bike while hooked up to electrodes that record your heart’s electrical activity. If you are unable to use a treadmill or stationary bike, your doctor may use medication to simulate the effects of exercise on your heart.