How Are Cardiac Arrhythmias Diagnosed?
An arrhythmia may be “silent” and not cause any symptoms. A doctor can detect an irregular heartbeat during an examination by taking your pulse, listening to your heart or by performing diagnostic tests.
If symptoms occur, they may include:
- Palpitations: A feeling of skipped heartbeats, fluttering, “flip-flops” or feeling that the heart is “running away”
- Pounding in the chest
- Dizziness or feeling lightheaded
- Shortness of breath
- Chest discomfort
- Weakness or fatigue (feeling very tired)
After evaluating your symptoms and performing a physical examination, the cardiologist may perform a variety of diagnostic tests to help confirm the presence of an arrhythmia and indicate its causes. Some tests that may be done to confirm the presence of an irregular heart rhythm include:
- Electrocardiogram (ECG or EKG): a picture of the electrical impulses traveling through the heart muscle. An ECG is recorded on graph paper, through the use of electrodes (small, sticky patches) that are attached to your skin on the chest, arms and legs.
- Ambulatory monitors, such as:
- Holter monitor: A small portable recorder that is attached to electrodes on your chest. It continuously records your heart’s rhythm for 24 hours.
- Transtelephonic monitor: A small monitor is attached to electrode leads, usually on your finger or wrist. With the help of this device, your heart’s rhythm is transmitted over the phone line to your doctor’s office.
- Transtelephonic monitor with a memory loop: A small, portable recorder that is worn continuously for an extended period of time to record and save information about your heart’s rhythm around the time you experience an arrhythmia. The recording is triggered by pushing a button (event button). The rhythm is recorded, saved and transmitted over the phone line.
- Stress test: a test used to record arrhythmias that start or are worsened with exercise. This test also may be helpful in determining if there is underlying heart disease or coronary artery disease associated with an arrhythmia.
- Echocardiogram: a type of ultrasound used to provide a view of the heart to determine if there is heart muscle or valve disease that may be causing an arrhythmia. This test may be performed at rest or with activity.
- Cardiac catheterization: using a local anesthetic, a catheter (small, hollow, flexible tube) is inserted into a blood vessel and guided to the heart with the help of an X-ray machine. A contrast dye is injected through the catheter so X-ray movies of your coronary arteries, heart chambers and valves may be taken. This test helps your doctor determine if the cause of an arrhythmia is coronary artery disease. This test also provides information about how well your heart muscle and valves are working.
- Electrophysiology study (EPS): a special heart catheterization that evaluates your heart’s electrical system. Catheters are inserted into your heart to record the electrical activity. The EPS is used to find the cause of the abnormal rhythm and determine the best treatment for you. During the test, the arrhythmia can be safely reproduced and terminated.
- Tilt table test (also called a passive head-up tilt test or head upright tilt test): records your blood pressure and heart rate on a minute-by-minute basis while the table is tilted in a head-up position at different levels. The test results may be used to evaluate heart rhythm, blood pressure and sometimes other measurements as you change position.