alexa Enhanced parasympathetic tone shortens atrial refractoriness in man.


Anatomy & Physiology: Current Research

Author(s): Prystowsky EN, Naccarelli GV, Jackman WM, Rinkenberger RL, Heger JJ,

Abstract Share this page

Abstract The purpose of this study was to determine the effects of enhanced vagal tone on human right atrial refractoriness in 12 patients. A specially built neck collar connected to a vacuum source was placed around the patient's neck and enhanced vagal tone was produced during neck suction using intracollar negative pressures of 50 to 60 mm Hg. Refractory periods were determined with a catheter electrode positioned in the high right atrium near the sinus node. Induced neck suction increased the spontaneous sinus cycle length from 837 +/- 96 to 1.136 +/- 273 ms (p less than 0.001) and shortened the atrial effective refractory period from 241 +/- 24 to 230 +/- 20 ms (p less than 0.01) and the atrial functional refractory period from 272 +/- 32 to 262 +/- 29 ms (p less than 0.01). In 2 of 2 patients, collar-induced decreases in atrial refractoriness and increases in spontaneous cycle length were prevented after atropine (0.03 mg/kg) was given intravenously. It is concluded that enhanced vagal tone mediated through muscarinic receptors shortens atrial refractory periods in man.
This article was published in Am J Cardiol and referenced in Anatomy & Physiology: Current Research

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version