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Arrythmia Definition

An arrhythmia is an abnormal heart rhythm. There are several types of arrhythmias, named by the chambers of the heart in which they occur (atria or ventricles) and by what effect they have on the heart's
rhythm. An arrhythmia may happen for different reasons:

  • The heartbeat may begin in a part of the heart other than the sinus node
  • The sinus node may develop an abnormal rate or rhythm
  • A heart block (delay in the normal flow of electrical impulses that cause the heart to beat) may be present.

Any of these may cause the heart to skip a beat, beat too fast, or beat too slow. The two major types of heart arrhythmia are tachycardia (fast arrhythmia) and bradycardia (slow arrhythmia).

Tachycardia is defined by a heart rate over 100 beats per minute. There are three major types of tachycardia:

  1. Atrial tachycardia (starting in the atria)
  2. Supraventricular tachycardia (starting above the ventricles)
  3. Ventricular tachycardia (starting in the ventricles)

Bradycardia refers to a slow heart rhythm, caused by a failure of the heart signals to fire as they should.

It is not always clear what causes an arrhythmia. Possible causes include heart disease, aging, myocardial ischemia (reduced blood flow to heart muscle), electrical conduction disorders, stress, caffeine, tobacco, alcohol, diet pills, and cough medication. In the case of tachycardia, complicating factors include heart attack, heart valve disease, angina, and emphysema.
Diagnosis & Treatment

Arrhythmias are diagnosed through medical history, physical examination, and EKG. Upon diagnosis, tachycardia is treated with medical therapies including anticoagulants to prevent blood clots and stroke, anti-arrhythmics to control rate and rhythm of the heart or beta-blockers to help lower blood pressure or other surgical options. For select patients, surgical treatments such as radio-frequency ablation or ICD implantation may be recommended. Bradycardia is most often treated with a pacemaker to keep the heart beating at a regular pace.