Diagnostic Methods: Heart Rhythm

Heart rhythm problems (arrhythmias) can be diagnosed using a variety of methods. The method depends upon the suspected heart rhythm problem and the physician. An ECG (electrocardiogram) is the most common test. Holter monitors, external loop recorders, implantable loop recorders, and tilt-table tests may be used when the ECG does not record the arrhythmia. An electrophysiology (EP) study may be done when the arrhythmia is identified as a fast heart rhythm problem (tachyarrhythmia). Other diagnostic tests may check for structural heart disease (heart failure, heart valve disease, coronary artery disease).

   • Electrocardiogram (ECG)
   • Exercise ECG or Stress Test
   • Holter Monitor (24-72 hour ECG)
   • External Loop Recorder
   • Implantable Loop Recorder
   • Tilt Table Test
   • Electrophysiology (EP) Study







Electrocardiogram (ECG)
A graphical record of the heart's rhythm and rate for a second. To record the ECG, patches with wires are placed on the chest and the wires are connected to a monitor. This is typically done in a physician's office or hospital setting. This test helps narrow the search for identifying the specific arrhythmia.

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Exercise ECG or Stress Test
A graphical recording of the heart's rhythm during exertion. The exertion may be created using a treadmill machine or by using medications that mimic exercise. This test helps evaluate whether exercise can create an arrhythmia or make it worse. Or, it can show if there may be not be enough blood flowing to the heart (ischemia).

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Holter Monitor (24-72 hour ECG)
A device that measures and records heart rhythm over 1-3 days. This test may be done when an ECG does not show the arrhythmia and it still is suspected to be the cause of symptoms.

Patches with wires are placed on the chest. The wires are connected to a portable monitor that can be attached to a purse or belt.

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External Loop Recorder
A device that monitors heart rhythm and rate for up to one month. During this test, the patient wears a device on the wrist or around the waist. When symptoms are experienced, the patient presses a button on the device to make a recording of the heart activity that just occurred.

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Implantable Loop Recorder
A device that continuously monitors the heart rhythm for up to 14 months. This small device is placed under the skin during an approximate 20-minute procedure using a local anesthetic. When a symptom is experienced, the patient places a hand-held activator over the recorder. Later, a physician analyzes the stored information.

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Tilt Table Test
This procedure attempts to simulate conditions that may cause the arrhythmia. This procedure enables a physician to understand how blood pressure, heart rate and rhythm respond to a change in position from lying down to standing. The patient is positioned on a table, given medication, and the table is tilted by varying degrees. The test typically lasts for 20 to 45 minutes.

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Electrophysiology (EP) Study
Several tests are performed in a special lab in the hospital that can take several hours. These tests help pinpoint the location, the type of arrhythmia, and how the arrhythmia responds to treatment. During an EP study, the patient is sedated and small catheters are guided to the heart. The heart's rhythm is recorded as small amounts of electricity are delivered through the catheter. This internal recording is often compared with an external recording (from electrodes placed on the patient's chest and back) taken at the same time.

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