What is an arrhythmia?

Cardiac arrhythmia is the medical term for an abnormal heart rhythm. This is a problem with the electrical wiring of the heart. Arrhythmia can occur in the upper chambers of the heart (atria) or the lower chambers of the heart (ventricle).


There are a variety of causes of abnormal heart rhythm that fall under two main categories:

  • Pacemaker problems: when the heart’s natural pacemaker fails
  • Conduction problems: when the path of an electrical impulse is blocked; or the electrical impulse joins a short-circuit generating a continuous loop


Some arrhythmias result in symptoms, while others can be debilitating or potentially life-threatening. Common symptoms are:

  • Palpitations
  • Dizziness / light headedness
  • Fainting / loss of consciousness


Arrhythmias are commonly undetected or misdiagnosed. Blackouts may be indicative of a dangerous arrhythmia, but could also be the result of a simple faint.

Cardiac Ablation for Arrhythmias from Khan Academy.

An electrocardiogram (ECG) is a basic test to record a heart rhythm trace. A Holter monitor records ECG signals for 24 hours and an event monitor can do this for up to a few weeks. For infrequently occurring arrhythmias, an internal loop recorder can be implanted under the skin of the chest to record the heart rhythm for up to 3 years. An exercise test on a treadmill may be used to provoke an arrhythmia. An electrophysiology study (EP study) can be done to manually stimulate the heart to record the heart impulse internally and induce abnormal heart rhythms to obtain a diagnosis.


Slow arrhythmias are commonly treated by a cardiac pacemaker. Fast arrhythmias (tachycardias) can be treated with medications, an internal defibrillator or cardiac ablation. The utility of each of these treatment options depend upon the diagnosis and cause of your arrhythmia. Each of the common diagnoses and treatment options available are explained in detail in the next sections.