Arrhythmia • Cardiovascular Network of Canada — CANet


DISCLAIMER — All information contained in this webpage is NOT intended as specific medical advice for any individual with a medical condition similar to that described herein.

What Is an Arrhythmia?

An arrhythmia is an uneven heartbeat. It means your heart is out of its usual rhythm.

It may feel like your heart skipped a beat, added a beat, or is “fluttering.” It might feel like it’s beating too fast (which doctors call tachycardia) or too slow (called bradycardia). Or you might not notice anything.

Arrhythmias can be an emergency, or they could be harmless. If you feel something unusual happening with your heartbeat, get medical help right away so doctors can find out why it’s happening and what you need to do about it.

Symptoms of Arrhythmias

An arrhythmia can be silent, meaning you don’t notice any symptoms. Your doctor may spot an uneven heartbeat during a physical exam.

If you have symptoms, they may include:

  • Palpitations (a feeling of skipped heartbeats, fluttering, or “flip-flops”)
  • Pounding in your chest
  • Dizziness or feeling lightheaded
  • Fainting
  • Shortness of breath

  • Chest pain or tightness
  • Weakness or fatigue (feeling very tired)
  • Anxiety
  • Blurry vision
  • Sweating

Arrhythmia Causes

You could have an arrhythmia even if your heart is healthy. Or it could happen because of:

  • Heart disease
  • The wrong balance of electrolytes (such as sodium or potassium) in your blood
  • Heart injury or changes such as reduced blood flow or stiff heart tissue
  • Healing process after heart surgery

  • Certain medications
  • Problems with the electrical signals in your heart
  • Strong emotions, stress, or surprise
  • Things in your daily life like alcohol, tobacco, caffeine, or exercise

Types of Arrhythmias

Heart arrhythmias fall into two categories. One starts from inside the heart’s lower chambers. Doctors call this kind “ventricular” because the lower chambers of the heart are the ventricles. The other kind starts outside or above the ventricles. You may hear these called “supraventricular” arrhythmias.

The most common types of arrhythmia include:

  • Atrial fibrillation. This happens when your heart sends electrical impulses at a fast rate, causing a fast and irregular heartbeat.
  • Atrial flutter. Your heart misfires its electrical impulses, bringing on an irregular or fast heartbeat.
  • Premature atrial contractions. Doctors may call these “PACs” or “APCs.” When your heart contracts earlier than expected, it adds an extra heartbeat.
  • Premature ventricular complex, or PVCs. Your heart fires an abnormal electrical impulse, causing an early heartbeat. Usually, the heart returns to its normal rhythm right away.
  • Sick sinus syndrome. This has nothing to do with the sinuses in your head. It’s about your heart’s SA node. Your electrical system fires abnormally, slowing down your heart rate.
  • Supraventricular arrhythmias. These are more common, are generally temporary, and often aren’t serious. They can create a sensation of a fast heartbeat and dizziness.
  • Supraventricular tachycardiaor paroxysmal SVT. This is when your heart beats rapidly because of abnormal electrical impulses above the lower heart chamber.
  • Ventricular tachycardia. Your heart sends fast impulses and causes a very rapid heart rate. This is usually serious. Get medical help right away.
  • Ventricular fibrillation. Electrical impulses start in a fast and disordered sequence, which causes your heart to lose its ability to beat and pump blood. This typically causes cardiac arrest.

Source: WEbMD