Document Detail

Termination of sustained atrial flutter and fibrillation using low-voltage multiple-shock therapy.
MedLine Citation:
PMID:  20969974     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Defibrillation therapy for atrial fibrillation (AF) and flutter (AFl) is limited by pain induced by high-energy shocks. Thus, lowering the defibrillation energy for AFl/AF is desirable.
OBJECTIVE: In this study we applied low-voltage multiple-shock defibrillation therapy in a rabbit model of atrial tachyarrhythmias comparing its efficacy to single shocks and antitachycardia pacing (ATP).
METHODS: Optical mapping was performed in Langendorff-perfused rabbit hearts (n = 18). Acetylcholine (7 ± 5 to 17 ± 16 μM) was administered to promote sustained AFl and AF, respectively. Single and multiple monophasic shocks were applied within 1 or 2 cycle lengths (CLs) of the arrhythmia.
RESULTS: We observed AFl (CL = 83 ± 15 ms, n = 17) and AF (CL = 50 ± 8 ms, n = 11). ATP had a success rate of 66.7% in the case of AFl, but no success with AF (n = 9). Low-voltage multiple shocks had 100% success for both arrhythmias. Multiple low-voltage shocks terminated AFl at 0.86 ± 0.73 V/cm (within 1 CL) and 0.28 ± 0.13 V/cm (within 2 CLs), as compared with single shocks at 2.12 ± 1.31 V/cm (P < .001) and AF at 3.46 ± 3 V/cm (within 1 CL), as compared with single shocks at 6.83 ± 3.12 V/cm (P =.06). No ventricular arrhythmias were induced. Optical mapping revealed that termination of AFl was achieved by a properly timed, local shock-induced wave that collides with the arrhythmia wavefront, whereas AF required the majority of atrial tissue to be excited and reset for termination.
CONCLUSION: Low-voltage multiple-shock therapy terminates AFl and AF with different mechanisms and thresholds based on spatiotemporal characteristics of the arrhythmias.
Christina M Ambrosi; Crystal M Ripplinger; Igor R Efimov; Vadim V Fedorov
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-10-19
Journal Detail:
Title:  Heart rhythm : the official journal of the Heart Rhythm Society     Volume:  8     ISSN:  1556-3871     ISO Abbreviation:  Heart Rhythm     Publication Date:  2011 Jan 
Date Detail:
Created Date:  2010-12-27     Completed Date:  2011-05-24     Revised Date:  2014-09-18    
Medline Journal Info:
Nlm Unique ID:  101200317     Medline TA:  Heart Rhythm     Country:  United States    
Other Details:
Languages:  eng     Pagination:  101-8     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
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MeSH Terms
Atrial Fibrillation / therapy*
Atrial Flutter / therapy*
Electric Countershock / methods*
Electrodes, Implanted
Pain Measurement
Voltage-Sensitive Dye Imaging
Grant Support
Comment In:
Heart Rhythm. 2011 Jan;8(1):109-10   [PMID:  21044899 ]

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

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