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Arrhythmia is an abnormal rhythm of the heart. Each heartbeat starts with an electrical impulse from the sinus node, which is the normal pacemaker of the body. The impulse travels along the other parts of the electrical system to activate the atria and the ventricles, thereby completing a single heartbeat. Damage to any part of the heart's electrical system can result in an abnormally slow heart rate, called bradycardia, or an abnormally fast heart rate, called tachycardia.


Symptoms of bradycardia (a slow heart rate) include:

  • Fatigue
  • Poor exercise tolerance
  • Dizziness
  • Loss of consciousness

Symptoms of tachycardia (a fast heart rate) include:

  • Palpitations
  • Dizziness
  • Shortness of breath
  • Fainting


Bradycardia (slow heart rate) may be improved or prevented with the surgical insertion of a permanent pacemaker. This mechanical device provides an electrical trigger for a heart beat when and where it is needed.

Tachycardia (fast heart rate) may be treated with: 
  • Medications
  • Electrical therapy, which involves delivering electrical impulses directly to the atrial or ventricular tissue
  • Radiofrequency ablation, which is generally performed in the cardiac catheterization lab, usually with the patient under general anesthesia. Catheters or wires are placed into the patient's heart by way of large veins in the legs and neck. The cardiologist then "maps" the heart's electrical system to locate the electrical short-circuit or over-active cells. Once found, this small amount of abnormal tissue can be destroyed by direct heating of the tip of a catheter using radiofrequency current
  • Heart surgery


Learn more about our specialized teams caring for these patients

Make an Appointment

The specialists in Lurie Children's Heart Center treat children with arrythmia. Learn how to make an appointment.

Related Specialties & Services

Read about the specialty areas and services that treat Arrhythmia/Electrophysiology.

How to Use an AED 

Seconds count when a person is in cardiac arrest, and the use of an AED can be the difference between life and death. We've created an infographic to explain how AEDs work and how to use them.

View the infographic.