This Article Full Text Full Text (PDF) All Versions of this Article: 107/20/2583    most recent 01.CIR.0000068339.04731.4Dv1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chiou, C.-W. Articles by Prystowsky, E. N. Search for Related Content PubMed PubMed Citation Articles by Chiou, C.-W. Articles by Prystowsky, E. N. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB PHENYLEPHRINE Related Collections Arrhythmias, clinical electrophysiology, drugs

(Circulation. 2003;107:2583.)
© 2003 American Heart Association, Inc.

Clinical Investigation and Reports

Effects of Continuous Enhanced Vagal Tone on Dual Atrioventricular Node and Accessory Pathways

Chuen-Wang Chiou, MD; Shih-Ann Chen, MD; Ming-Ho Kung, MD; Mau-Song Chang, MD; Eric N. Prystowsky, MD

From the Division of Cardiology, Veterans General Hospital-Taipei and Kaohsiung, National Yang-Ming University, School of Medicine, Taiwan, and The Care Group (E.N.P.), Indianapolis, Ind.

Correspondence to Eric N. Prystowsky, MD, The Care Group, 8333 Naab Road, Suite 400, Indianapolis, IN 46260-1919. E-mail eprystow{at}thecaregroup.com

Background— The aim of this study was to test the electrophysiological effects of continuous enhanced vagal tone on dual atrioventricular (AV) nodal and accessory pathways.

Methods and Results— This study included 10 patients with typical, slow-fast AV nodal reentrant tachycardia (AVNRT) and 10 patients with AV reciprocating tachycardia. Electrophysiological data were measured before and during continuous vagal enhancement by using phenylephrine infusion (0.6 to 1.5 µg/kg per min). For patients with AVNRT, during phenylephrine infusion, 1:1 conduction times over the anterograde fast and slow and retrograde fast pathways were prolonged (453±64 to 662±120 ms, P<0.001; 379±53 to 443±95 ms, P<0.05; 405±112 to 442±118 ms, P<0.05). The effective refractory period and functional refractory period of the anterograde fast pathway were prolonged with phenylephrine (394±73 to 544±128 ms, P<0.001; 454±60 to 596±118 ms, P<0.001). In contrast, the effective refractory period and functional refractory period of the anterograde slow and retrograde fast were not significantly changed. No significant change was observed in the conduction or refractoriness of the accessory pathways in patients with AV reciprocating tachycardia nor in atrial or ventricular refractoriness.

Conclusions— Enhanced vagal tone produces disparate effects on the refractoriness of the slow and fast AV nodal conduction pathways, with the anterograde fast pathway being the most sensitive. These changes are conducive to induction of AVNRT with a premature atrial complex and may explain in part the relatively common occurrence of AVNRT during sleep or other periods of presumed increased parasympathetic tone.

Key Words: vagus nerve • tachycardia • electrophysiology • Wolff-Parkinson-White syndrome • atrioventricular node

This article has been cited by other articles:

				F. Onorati, A. Curcio, G. Santarpino, D. Torella, P. Mastroroberto, L. Tucci, C. Indolfi, and A. Renzulli Routine ganglionic plexi ablation during Maze procedure improves hospital and early follow-up results of mitral surgery. J. Thorac. Cardiovasc. Surg., August 1, 2008; 136(2): 408 - 418. [Abstract] [Full Text] [PDF]