Millions of Canadians experience irregular heart rhythms, known as arrhythmias. Are you a patient who has been diagnosed with an arrhythmia? Do you care for someone with one of these conditions? CANet includes Canada’s top clinical experts and researchers in this field.

For most people, the heart beats between 60 to 80 times per minute in a regular rhythm. An arrhythmia is an abnormal heart beat. The beats may be too slow, or too fast, or irregular.

Your heart has a natural pacemaker, called the sinus node, which creates electrical impulses that cause your heart to beat. When there is a disorder in this electrical system, an arrhythmia may occurs.

Arrhythmia [ah-rith´me-ah]

Any rhythm in the heart that falls outside the norm with respect to rate, regularity, and propagation sequence of depolarization wave.

What Causes Arrhythmias?

Damage from heart diseases and disorders can cause arrhythmias. These include:

  • Coronary artery disease
  • Injury from a heart attack
  • High blood pressure
  • Heart valve disease
  • Congenital heart disease

Arrhythmias can also be caused by other things, including:

  • Genetic disorders (such as Long QT Syndrome)
  • Diabetes
  • Endocrine disorders (such as problems with the thyroid gland),
  • Excess alcohol and some street drugs
  • Excess caffeine
  • Smoking
  • Some prescription medications or dietary supplements
  • Stress

Arrhythmias may occur frequently in normal hearts.


Damage from heart diseases and disorders can cause arrhythmias. These include:

Although many arrhythmias occur normally and will not cause serious health problems, they can lead to troublesome symptoms, such as dizziness or chest discomfort. Other arrhythmias are more dangerous and can affect the supply of blood to the heart or other organs. Left untreated, this can sometimes lead to stroke, heart attack, heart failure, or sudden death.

  • Atrial fibrillation is the most common sustained arrhythmia. Atrial fibrillation may last for seconds or be permanent. This condition is more common in older people and can have many different causes.
  • Ventricular fibrillation is the most dangerous type of arrhythmia. Irregular signals prevent the ventricles from contracting, and blood from being pumped throughout the body. Without immediate treatment it may be fatal. Treatment is administered by a defibrillator, which administers an electric shock to the body, allowing the heart to reset itself.
  • Other types of arrhythmia include bradycardia, tachycardia, atrial flutter, paroxysmal supraventricular tachycardia, and Wolff-Parkinson-White syndrome.


Symptoms of arrhythmia include:

  • Heart palpitations (a sensation of racing or irregular heartbeat)
  • Light-headedness or dizziness
  • Fainting or almost fainting
  • Shortness of breath
  • Chest pain or discomfort

Many of these symptoms can be confused with the effects of aging or physical inactivity, or with other diseases affecting the heart.

If you experience symptoms of arrhythmia, you should call your doctor. A number of tests are used to diagnose arrhythmias, including:

  • Electrocardiogram to record the electrical activity of your heart
  • Echocardiogram to create a moving picture of your heart and see how strongly your heart is pumping
  • Holter monitor to record your heart rhythm for several days
  • Event monitor to record your heart rhythm when you notice symptoms
  • Treadmill (stress) test to see your heart’s electrical activity during exercise
  • Electrophysiology studies to track and stimulate electrical impulses in the heart to find the cause of the abnormal rhythm.


There are many ways to treat arrhythmias, depending on their seriousness. Many arrhythmias require no treatment, while others may require immediate treatment. Treatments include drug therapies, implantable devices, ablation, and lifestyle changes.

  • Drug therapies: There are many medications available to slow the heartbeat, keep the heart rhythm normal, or help prevent blood clots.
  • Implantable devices are used to help the heart beat in a normal rhythm. A pacemaker is a small device implanted near the heart, which delivers a small electrical pulse when the heart beats too slowly. An implantable cardioverter-defibrillator is similar to a pacemaker but can deliver an electrical shock to restore normal heart rhythms.
  • Ablation is a minimally invasive technique, in which an electrode is inserted to heat and destroy a small area of tissue that is causing abnormal electrical signals.
  • Lifestyle changes can sometimes, but not always, reduce the arrhythmias. Lifestyle changes include quitting smoking, limiting alcohol, caffeine, and over-the-counter medications that include stimulants, increasing physical activity, avoiding stress, and maintaining a healthy weight.

How to get involved

Contact us if you are interested in becoming involved in arrhythmia research and you fit the following criteria:
– Have significant experience of living with an arrhythmia
– Are in a period of stable health
– Have a constructive critical attitude and a certain distance from your own story
– Are willing to help people by working with both patients and health professionals and researchers

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