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Ectopic pacemaker



An ectopic pacemaker or ectopic focus is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the human heart. Acute occurrence is usually non-life threatening, but chronic occurrence can progress into ventricular fibrillation.

Additional recommended knowledge

Contents

Etiology

Ectopic pacemakers can occur within healthy hearts in response to various stimulating events, such as:

Physiology

An ectopic pacemaker can reside within a part of the conduction system of the heart, or within the muscle cells of the atria or ventricles. When an ectopic pacemaker initiates a beat, premature contraction occurs. A premature contraction will not follow the normal signal transduction pathway, and can render the heart refractory or incapable of transmitting the normal signal from the SA node.

Diagnosis

On an ECG, the QRS complex will be abnormally shaped. It can be perceived as a skipped beat on both the ECG and through normal pulse-taking.

References

  1. ^ Carol, Mattson, Port. Pathophysiology: Concepts of Altered Health States 7th Ed, Pg 588. Lippincott Williams & Wilkins, 2005. ISBN 0-7817-4988-3
  2. ^ Keller-Wood, Maureen. "Electrical Activity in the Heart." Lecture at the University of Florida College of Pharmacy, 23-Oct-2007.

See Also

Cardiac ectopy

Clinical cardiac electrophysiology

Electrical conduction system of the heart

 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ectopic_pacemaker". A list of authors is available in Wikipedia.
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