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Fact Sheet


What is it?

Disorganized electrical signals in the heart

Risk Factors

  • Heart surgery

  • Heart attack

  • Thyroid disease

  • Certain medications

  • Genetics


  • Palpitations

  • Fast or slow heartbeat

  • Fatigue

  • Lightheadedness or fainting


  • Electrocardiogram

    • Holter monitor

    • Event recorder

    • Loop recorder

  • Electrophysiology testing


  • Antiarrhythmic medications

  • Pacemaker or defibrillator

  • Surgical or catheter ablation


Schedule a consultation with one of our cardiologists

What is an arrhythmia?

The squeezing action of the heart is normally a well coordinated process that starts high in the loading chambers (the atria) before going to the pumping chambers (the ventricles). At rest, your heart should beat in a regular rhythm and at a normal rate, usually between 60 and 100 beats per minute. When your heart beats too fast, too slow, or the gaps between heartbeats become irregular, this is called an arrhythmia. Atrial fibrillation is one of the most common arrhythmias, but there are many others as well. Some of them, like supraventricular tachycardia (SVT), are relatively benign while others may need more immediate treatment.

What causes an arrhythmia?

Generally, arrhythmias are caused when the electrical signal that triggers a normal heartbeat becomes abnormal. This can happen in a number of ways. First, the trigger that starts a heartbeat can fire either too fast or too slow. Sometimes, the trigger comes from a part of the heart that isn’t meant to trigger a heartbeat, and this can also cause problems. Also, because the heart has electrical properties, it can sometimes develop or short-circuit, or the timing of the electrical pathway is a little off, and this can lead to the signal going places it shouldn’t. All of these can lead to a heartbeat that isn’t normal: an arrhythmia.


Risk factors for developing an arrhythmia


The mechanical and electrical properties of the heart are closely related, so changes in the structure of the heart can lead to an arrhythmia. This includes problems that you may have been born with (congenital heart disease), but structural changes can also come after the heart tissue scars after being damaged, like after heart surgery or even a heart attack. On the other hand, thyroid disease and some medications are known to interact with the electrical properties of the heart to cause an arrhythmia.

Symptoms of an arrhythmia


Common symptoms of arrhythmias include feeling like you have an irregular or fast heartbeat (palpitations), fatigue, shortness of breath, or possibly lightheadedness or fainting. Depending on your specific arrhythmia, the symptoms may not be present all the time, and they may come and go quickly, without any apparent trigger or warning.



[1] Fu DG. Cardiac Arrhythmias: Diagnosis, Symptoms, and Treatments. Cell Biochem Biophys. 2015;73(2):291-296.

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