Common Tests for Arrhythmia

Updated:May 10,2016

Several tests can help your doctor diagnose an arrhythmia. View an animation of arrhythmia.

Common Tests for Arrhythmia

An arrhythmia is considered documented if it can be recorded on an electrocardiogram (ECG or EKG.) This is the standard clinical tool for diagnosing arrhythmias. It records the relative timing of atrial and ventricular electrical events. It can be used to measure how long it takes for impulses to travel through the atria (the heart's upper chambers), the atrioventricular (AV) conduction system and the ventricles (the heart's two lower, pumping chambers). Because of the fleeting nature of arrhythmias, a person who complains of symptoms that suggest arrhythmia may often have an ECG that appears normal. Electrocardiographic techniques are passive; they can only record an arrhythmia if it occurs spontaneously while the ECG is being taken.

To conduct an ECG, the healthcare professional places small patches or stickers called electrodes on different parts of the body. One is put on each arm and leg and several across the chest. They don't hurt. With various combinations of these electrodes, different tracings of the heart's electrical activity can be made and permanently recorded on paper or in a computer.

Three major waves of electric signals appear on the ECG. Each one shows a different part of the heartbeat.

  • The first wave is called the P wave. It records the electrical activity of the atria (the heart’s upper chambers).
  • The second and largest wave, the QRS wave, records the electrical activity of the ventricles (the heart’s lower chambers).
  • The third wave is the T wave. It records the heart's return to the resting state.
Doctors study the shape and size of the waves, the time between waves and the rate and regularity of beating. This tells a lot about the heart and its rhythm.

Learn more about Electrocardiogram (ECG or EKG).

This content was last reviewed on 10/23/2014.



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