Nicotine exposure in ag...( Bethesda MD Large numbers of American...)

Bethesda, MD Large numbers of Americans still smoke cigarettes or use over-the-counter nicotine products such as patches and gums to satisfy their craving for nicotine. However, serious and sometime fatal cases of atrial fibrillation (AF) have been reported in patients who use a nicotine product. This is particularly true when the individual has smoked while using a nicotine patch. AF is the most common type of disturbance of the normal rhythm of the heart and affects some two million people annually. At its most devastating, AF results in stroke (brain attack) and congestive heart failure. Previous studies have concluded that transdermal nicotine patches should be used cautiously because of the high risk of AF they carry for patients with heart disease.

How specific atrial substrates control and modulate atrial vulnerability, which can induce atrial tachycardia (AT) and AF (AT/AF) in response to acute doses of nicotine, is poorly understood. One substrate known to modulate atrial vulnerability to inducible AT/AF is enhanced atrial interstitial fibrosis, commonly found among the aging. Against this backdrop a team of researchers has hypothesized that nicotine concentrations found in the blood of certain smokers exerts a differential influence on the atria and on different substrates for AT/AF. They tested their hypothesis by determining atrial sensitivity to nicotine by inducible AT/AF in young and old rats.

A New Study
The authors of a new study entitled, "Age-related Sensitivity to Nicotine for Inducible Atrial Tachycardia and Atrial Fibrillation," are Hideki Hayashi, Chikaya Omichi, Yasushi Miyauchi, William J. Mandel, Shien-Fong Lin, Peng-Sheng Chen and Hrayr S. Karagueuzian, all of the Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center and David Geffen School of Medicine, University of California, Los Angeles, CA. Their findings appear in the November 2003 edition of the American Journal of Physiology--
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Contact: Donna Krupa
djkrupa1@aol.com
703-527-7357
American Physiological Society
12-Nov-2003

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