Document Detail


Reduction of the internal atrial defibrillation threshold with balanced orthogonal sequential shocks.
MedLine Citation:
PMID:  12380930     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
INTRODUCTION: The aim of this study was to determine the atrial defibrillation threshold (ADFT) of a first shock across the standard right atrium (RA) to distal coronary sinus (dCS) configuration followed by a second shock along the atrial septum with a standard sequential waveform (the second shock leading edge equaled the first shock trailing edge) and a balanced sequential waveform (the leading edges of both shocks were equal). METHODS AND RESULTS: In nine sheep atrial fibrillation was induced with acetyl-beta-methylcholine and burst pacing. A catheter was placed with electrodes in the dCS, proximal coronary sinus (pCS), and RA. A J-shaped catheter was positioned with an electrode at Bachmann's bundle (BB) while another catheter was positioned with an electrode in the superior vena cava (SVC). The ADFTs of six single- and dual-pathway configurations were determined with single, standard sequential, or balanced sequential shocks. The ADFT of the RA-->dCS configuration (0.86 +/- 0.27 J, 159 +/- 29 V, 2.42 +/- 0.36 A) was significantly reduced when followed by an SVC-->pCS (0.58 +/- 0.17 J, 112 +/- 20 V, 1.64 +/- 0.39 A) or a BB-->pCS shock (0.64 +/- 0.16 J, 119 +/- 18 V, 1.81 +/- 0.38 A) with standard sequential shocks. With balanced sequential shocks, the peak voltage and current ADFTs were further significantly reduced (85 +/- 11 V and 1.24 +/- 0.21 A for second shock SVC-->pCS, and 93 +/- 13 V and 1.38 +/- 0.27 A for second shock BB-->pCS). CONCLUSION: The ADFT of the standard RA-->dCS shock is significantly reduced when followed by a second shock along the atrial septum delivered between electrodes in the pCS and either SVC or BB and ADFT is further reduced with balanced sequential shocks.
Authors:
Xiangsheng Zheng; Michael E Benser; Gregory P Walcott; William M Smith; Raymond E Ideker
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of cardiovascular electrophysiology     Volume:  13     ISSN:  1045-3873     ISO Abbreviation:  J. Cardiovasc. Electrophysiol.     Publication Date:  2002 Sep 
Date Detail:
Created Date:  2002-10-16     Completed Date:  2003-02-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9010756     Medline TA:  J Cardiovasc Electrophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  904-9     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Atrial Fibrillation / chemically induced,  physiopathology,  therapy
Defibrillators, Implantable*
Differential Threshold
Disease Models, Animal
Electric Countershock*
Electric Impedance
Electrodes, Implanted
Heart Atria / physiopathology,  surgery
Heart Conduction System / physiopathology,  surgery
Methacholine Chloride / adverse effects
Models, Cardiovascular
Parasympathomimetics / adverse effects
Sheep
Treatment Outcome
Vena Cava, Superior / physiopathology,  surgery
Grant Support
ID/Acronym/Agency:
HL-42760/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Parasympathomimetics; 62-51-1/Methacholine Chloride

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Autonomic control of the location and rate of the cardiac pacemaker in the sinoatrial fat pad of par...
Next Document:  Restitution properties and occurrence of ventricular arrhythmia in LQT2 type of long QT syndrome.