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UCLA Cardiac Arrhythmia Center


Patient Education


View video of Cardiac Arrhythmias


An arrhythmia is an abnormal heart rhythm.

Some arrhythmias can cause problems with contractions of the heart chambers by:

  • Not allowing the ventricles (lower chambers) to fill with an adequate amount of blood because an abnormal electrical signal is causing the heart to pump too fast or too slow.

  • Not allowing a sufficient amount of blood to be pumped out to the body because an abnormal electrical signal is causing the heart to pump too slowly or too irregularly.

  • Not allowing the top chambers to work properly. 

In any of these situations, the body's vital organs may not receive enough blood to meet their needs.

Atria: The two upper chambers of the heart - one on the right, one on the left.

Bradycardia: A heart rate of less than 60 beats per minute is called bradycardia. The average resting heart rate is 60 to 100 beats per minute.

Palpitations: A symptom sometimes associated with arrhythmias.  It is often described by people as a sensation of the heart "skipping," "jumping," "fluttering" or "racing."

Tachycardia: A fast heart rate, usually greater than 100 beats per minute.

Ventricles: The two lower chambers of the heart - one on the right, one on the left.

Helpful Links

Visit our Resources and Links page for helpful links regarding heart rhythm problems and various cardiac procedures.

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