Cardiac Tests to Diagnose Heart Rhythm Disorders

Your doctor may order diagnostic tests if you are having signs or symptoms of a heart problem. Symptoms of the two most common heart rhythm disorders, atrial fibrillation and atrial flutter, include heart palpitations (feeling like your heart is racing, pounding or fluttering), shortness of breath or dizziness. There are several tests (listed here in alphabetical order) that can be done to check for a fast or irregular heartbeat:

• Click image to launch an animation illustrating how an echocardiogram works.

  Cardiac computerized tomography (CT) — Cardiac computed tomography, or cardiac CT, uses an X-ray machine and a computer to take clear, detailed pictures of the heart. During a cardiac CT scan you will lie on a table. An X-ray machine will move around your body. The machine will take pictures of your heart and chest. A computer will put the pictures together to make a three-dimensional (3D) picture of your heart and chest.
• Cardiac magnetic resonance imaging (MRI) — A cardiac MRI uses radio waves, magnets and a computer to create pictures of your heart. During a cardiac MRI you will lie on a table inside a long tube-like machine. Cardiac MRI creates detailed pictures of your heart as it is beating. The MRI will create snapshots as well as videos. Doctors use cardiac MRI to see the beating heart, the parts of the heart and how the heart is working.
• Echocardiogram — An echocardiogram uses sound waves to produce images of your heart. Watch an animation showing how an echocardiogram works. This test allows your doctor to see how your heart muscle is moving and pumping blood.
  More on echocardiograms »
  
  You may have one of several types of echocardiograms:
  • Transthoracic echocardiogram (TTE) — This is a standard non-invasive (no incisions or cuts) echocardiogram that gives your doctor a picture of your beating heart. A technician spreads a special gel on your chest and then uses an imaging device, called a transducer, that gives off and reads sound waves. The imaging device records the sound waves bouncing off the walls and valves (echoes) in your heart. A computer then creates a video of your heart. This video can show the size of your heart, how well your heart is working, if the heart valves are working and if there are blood clots in your heart.
  • Transesophageal echocardiogram — A transesophageal echocardiogram, or a TEE, is often done when the doctor needs to get a good picture of the back of your heart. To get a clear picture, a probe called a transducer is placed down your esophagus (the tube that connects your mouth to your stomach). The esophagus passes right behind the heart. Having the probe positioned in the esophagus allows for better visualization of the atria. This procedure can be uncomfortable; therefore, a small amount of sedation can be given through an intravenous (IV) line to make you sleepy. A topical anesthesic spray is used to numb the back of the throat to enable the probe to be passed with minimal discomfort. Once the probe is in place, it works the same way as described above (TTE)
• Electrocardiogram (ECG or EKG) — An ECG is a snapshot of your heart's electrical activity. Stickers (electrodes) are attached to your chest, arms and legs. These electrodes measure the rate and rhythm of your heart. An ECG often is performed in your doctor's office, using a machine that prints out a graph showing electrical activity of different parts of the heart. AFL shows a very distinct "sawtooth" pattern on the ECG.More on slectrocardiograms »
• Event recorder or event monitor — An event monitor is a portable ECG that is used for patients who have an irregular heart rhythm every once in a while. You will carry this small device with you at all times and attach it to your chest when you feel symptoms, to make a one- to two-minute recording of their heart rhythm when they actually experience symptoms. This is useful for patients with relatively infrequent and brief symptoms and lets your doctor check heart rhythms at the time of symptoms.
• Holter monitor — A Holter monitor is a small portable device with electronic memory to record a series of ECGs over time. A Holter monitor runs continuously, and usually is worn for 24 to 48 hours. Stickers (electrodes) are placed on your chest and are then connected to a small recording machine that is usually worn around the waist. It records the electrical activity of your heart for your doctor to review later. Learn more about a holter monitor »
• Mobile cardiac monitoring — A mobile cardiac monitor is worn for up to 30 days. It monitors your heart beat when it is normal and will trigger a recording when it senses an abnormal rhythm. The results are automatically sent to your physician. Your physician uses this information to evaluate your symptoms and determine what is causing the arrhythmia. This type of monitor is helpful to diagnose AF in asymptomatic patients.

Additional Heart Tests

• Electrophysiology (EP) Study— during an EP study, arrhythmia events may be provoked to collect data; EP studies can help locate the specific areas heart tissue that give rise to the abnormal electrical impulses that cause arrhythmias
• Exercise Stress Test — a diagnostic test in which a person walks on a treadmill or pedals a stationary bicycle while hooked up to equipment that monitors the heart. The test monitors heart rate, breathing, blood pressure, electrical activity (on an electrocardiogram) and the person's level of tiredness. It shows if the heart's blood supply is sufficient and if the heart rhythm is normal. (Also known as Treadmill Test, Exercise Test, Exercise Cardiac Stress Test or ECST.)
• Heart Catheterization — A thin hollow tube called a catheter is inserted through a blood vessel and, under X-ray guidance, threaded to the heart in cardiac catheterization. The catheter can obtain tissue samples of heart muscle that may be damaged, measure the pressure in the heart, or diagnose blood vessel or heart valve disease.
• Implantable Loop Recorder — small device to help identify the causes of fainting or loss of consciousness (syncope). Certain heart disorders, such as arrhythmias, can cause fainting.
• Tilt Table Test — used to determine a cause of fainting.