This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

Eric Duncan, MD; Irwin Silverman, MD; Steven Swiryn, MD

Arch Intern Med. 1987;147(5):977-979.

	Since this article does not have an abstract, we have provided the first 150 words of the full text PDF and any section headings.

The sinus node is the dominant pacemaker in the normal human heart. Rhythms arising from any part of the heart other than the sinus node are considered ectopic.¹ Most tissues in the conduction system can manifest pacemaker activity. When the dominant pacemaker slows or fails (default, see below) or when conduction is interrupted (block, see below), these pacemakers have the potential to escape and become the dominant pacemaker of the heart. The more distally located a subsidiary pacemaker, the slower its escape rate (Lewis' "law of the heart"). Under pathologic conditions, these ectopic pacemakers can accelerate and become the dominant pacemaker of the heart (usurpation, see below).

Under usual circumstances, the atria and ventricles are driven by a single pacemaker. When the atria and ventricles are driven by different pacemakers, atrioventricular (AV) dissociation is said to be present. Pick and Langendorf² have described four basic mechanisms for AV . . . [Full Text PDF of this Article]

Author Affiliations
From the Division of Cardiology, Department of Medicine, Evanston Hospital and Northwestern University Medical School, Evanston, Ill. Dr Duncan is now with the Carle Clinic, Normal, Ill.

Footnotes
Accepted for publication Aug 20, 1986.

Reprint requests to Evanston Hospital, 2650 Ridge Ave, Evanston, IL 60201 (Dr Swiryn).

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?