Tests Used to Diagnose Abnormal Heart Rhythms
An abnormal heart rhythm, also called an arrhythmia, occurs when the heart beats too fast, too slow or irregularly. Some people with abnormal heart rhythms don’t experience any symptoms at all. Others may feel a fluttering or pounding in their chest when an abnormal rhythm occurs.
There are several tests that may be used to diagnose irregular heart rhythms.
An electrocardiogram is a measurement of the heart’s electrical activity recorded on a graph. An ECG is a non-invasive test that involves placing electrodes at specific locations on your body (chest, arms, and legs). Variations of ECG include:
- Resting ECG, which lasts about a minute while lying down.
- Exercise ECG or stress test, which involves exercising on a treadmill or stationary bike to assess changes in your heart’s electrical activity, as well as heart rate and blood pressure. If a person is unable to exercise, a heart-stimulating drug may be used instead.
- Signal-averaged ECG, which is used less commonly for more difficult diagnoses and lasts 15 to 20 minutes.
Portable ECG monitors
Portable monitors are worn for 24 hours or more to record the electrical activity of the heart during the course of normal activity. Patients may be asked to keep a diary of symptoms along with wearing the monitor. There are several different types of portable monitors, including:
- Holter monitor, which is the most commonly used and records a continuous ECG over a period of 24 to 48 hours. Electrodes are attached to the chest and connected to a small recording device as one goes about daily activities. The monitor is only removed for showering, swimming, or activities that lead to excessive sweating, as the electrodes can loosen or fall off.
- Event monitors are similar to a Holter monitor, but patients start the ECG recording by pushing a button when they feel symptoms. These are typically even smaller, worn longer, and are easy to remove for bathing.
- Mobile cardiac monitoring allows for electrical activity to be measured for a longer period of time (up to 30 days) and sent to the doctor regardless of symptoms. These may include an adhesive patch monitor, which are easy, convenient, comfortable, and water-resistant but more expensive because they are not reusable.
An echocardiogram—performed at rest or with activity—is an ultrasound of the heart that maps the shape and size of the heart with sound waves. It helps determine if a muscle abnormality or valve disease is causing an arrythmia.
Cardiac catheterization and electrophysiologic studies (EPS)
During these nonsurgical but invasive tests, a small, thin tube (catheter) is inserted through a vein in the leg or arm and guided to the heart using a special x-ray machine.
- Cardiac catheterization includes injecting dye to better view the heart’s valves, chambers, and arteries to determine if coronary artery disease, weak muscle, or non-working valves are impacting heart rhythm.
- Electrophysiological studies record data of the heart’s electrical activities and pathways and help doctors identify and treat the arrythmia type. During the test, an arrythmia is safely reproduced and terminated.
Tilt table test
Differences in blood pressure and heart rate are recorded as a patient lies flat on a table and is tilted to different levels. This test is typically used if a patient is experiencing fainting spells to determine if an arrhythmia is the cause.
Implantable loop recorder
This is a miniature recording device that is implanted underneath the skin over your heart. It can record the heart rhythm for up to two years and is useful in diagnosing intermittent or rarely occurring arrhythmias.
While the symptoms of some abnormal heart rhythms may seem mild, some arrhythmias can increase the risk of stroke and be life threatening. If you are experiencing abnormal heart rhythms, contact Oklahoma Heart Hospital today to schedule an appointment with one of our physicians.