Abnormal Heart Rhythms

Abnormal heart rhythms, also called arrhythmias, develop when a problem arises in the heart's electrical system. These can make the heart beat faster than it should, or beat with an irregular or disordered rhythm. Rhythm abnormalities range from mild to life threatening.

A faster-than-normal heartbeat is called tachycardia. A slower-than-normal heartbeat is called bradycardia.

There are many types of heart rhythm disorders. Some occur in the heart's upper chambers (the atria) and some occur in the lower chambers (the ventricles).


Symptoms of cardiac arrhythmias include:

  • fast or slow heartbeat
  • feeling like the heart is skipping beats
  • feeling lightheaded or dizzy
  • chest pain
  • shortness of breath
  • sweating

Common cardiac arrhythmias

Common heart rhythm problems include:

  • atrial fibrillation
  • atrial flutter
  • atrial tachycardia
  • heart block
  • long QT Syndrome
  • paroxysmal supraventricular tachycardia
  • premature atrial contractions
  • premature ventricular contraction
  • sinus node dysfunction
  • ventricular fibrillation
  • ventricular tachycardia