Arrhythmia

Diagnosis

To diagnose a heart arrhythmia, the patient may be asked about or tested for conditions that may trigger heart arrhythmia, such as heart disease or a problem with the thyroid gland. The patient may have two kinds of heart monitoring tests: active and passive.

Active Tests

These tests involve trying to actively induce an irregular heart beat while the patient is being closely monitored. They include:

Electrophysiology (EP) testing and mapping
Mayo Clinic is nationally recognized for its experience, research and innovations in electrophysiology assessments, using advanced equipment for recording and analyzing heart rhythms.

In this test, catheters (thin, flexible tubes) with electrodes at the tips, are threaded through the patient's blood vessels to a variety of spots within the heart. Once in place, the electrodes can precisely map the spread of electrical impulses through the heart. During the test, the electrophysiologist (a cardiologist who specializes in heart rhythms) may use the electrodes to stimulate the heart to beat at rates that may trigger — or halt — an irregular heart beat. This allows the doctor to observe the location of the arrhythmia and the mechanics of the heart that may be causing the irregular heart beat.

The ability to trigger and then stop an arrhythmia may also be used to test various treatment methods for their effectiveness. For example, if catheter radiofrequency ablation — a catheter-based treatment option for many arrhythmias — is determined by the doctor to be appropriate treatment, the procedure can be performed during EP testing. Read more about catheter radiofrequency ablation.

Stress test
Some arrhythmias are triggered or get worse when the patient is exercising. During a stress test, the patient may exercise on a treadmill or stationary bicycle, with close monitoring by an electrocardiograph or ECG of heart activity. The test may involve use of a drug to stimulate the heart similar to how exercise stimulates it. This may be particularly helpful to patients who have difficulty doing exercise. The stress test can also be used to detect coronary artery disease.

Passive Tests

These tests involve monitoring the heart during regular activity. They include:

Electrocardiogram (ECG)
In this test, electrodes (sensor patches with wires attached) are placed on the patient's skin to measure the electrical impulses given off by the heart. The ECG measures the timing and duration of each electrical phase in the heart beat.

Holter monitor
A Holter monitor is a portable ECG device that the patient wears for a day or more to record the heart's electrical activity during the patient's daily routine.

Event monitor
For irregular heart beats that occur sporadically, this portable ECG device is kept at home so the patient can attach it and activate the ECG recording only when experiencing symptoms of an arrhythmia. The device is small, about the size of a portable compact disc player, and can be clipped on to clothing and the electrodes (sticky pads with wires) applied by the patient on their chest. When the patient feels symptoms, a push of a button begins the ECG recording.

Echocardiogram (Doppler echocardiogram)
This test uses sound waves to produce detailed images of the patient's heart. Through a hand-held device (transducer) held on the patient's chest, sound waves bounce off the heart and are reflected back to produce video images of the heart's size, structure and motion. The echocardiogram can also be used to measure the heart's blood volume and the speed and direction of blood flow through the heart.

Transesophageal echocardiogram
In this test, a tube with a transducer (sound device) is inserted down the esophagus, the tube that runs from the throat to the stomach. Because the esophagus lies close to the heart, having the transducer placed there provides an even more detailed image of the heart's size, structure and motion.

A comprehensive diagnosis is critical in determining the best treatment options for the patient.