Heart - Cardiology & Cardiovascular Surgery

What is Arrhythmia?

An arrhythmia is an abnormal heart rhythm. It can be either too fast or too slow. The heartbeat is tightly controlled by the heart's electrical system, which usually keeps our heart beating in a regular pattern between 60 and 100 times a minute.

The healthy heart is a muscle about the size of a fist. It has four chambers: two atria on top, two ventricles below. Normally blood flows from the body to the heart to the lungs (to pick up additional oxygen), then back to the heart and out to the rest of the body. To keep your blood flowing effectively – not too fast and not too slow – your heart’s electrical system keeps things running. When the normal electrical system gets disrupted, arrhythmias can occur.

Common types of arrhythmias include:

  • atrial fibrillation
  • atrial flutter
  • sick sinus syndrome
  • sinus tachycardia
  • supraventricular tachycardia
  • ventricular tachycardia
  • ventricular fibrillation
  • premature ventricular contractions

Some arrhythmias can lead to more serious medical problems, such as sudden cardiac arrest or stroke. A cardiologist who specializes in heart rhythms, called an electrophysiologist, usually treats these conditions.

Symptoms of Arrhythmia

Many types of arrhythmias show no signs of symptoms. When they do appear, the most common symptoms are palpitations (sensations that your heart is pounding skipping or racing) or a slow or irregular heartbeat. More serious signs include:

  • dizziness or light-headedness
  • fainting
  • sweating
  • fatigue
  • shortness of breath

Women with arrhythmias may experience more symptoms than men.

Causes of Arrhythmia

Sometimes we cannot determine a specific cause for an abnormal heart rhythm. Conditions that can lead to the development of an arrhythmia include but are not limited to age; alcohol or drug abuse; diabetes; electrolyte imbalances; excessive caffeine; heart disease (including heart attack, an enlarged or weak heart, heart failure, myocarditis, and congenital heart disease); high blood pressure (hypertension); medications; supplements, and herbal remedies; sleep apnea; smoking; stress; and thyroid problems.