| Direct evidence of the role of virtual electrode-induced phase singularity in success and failure of defibrillation. | |
| | |
MedLine Citation:
|
PMID: 10969748 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
INTRODUCTION: We recently demonstrated that virtual electrode-induced phase singularity is responsible for arrhythmogenesis during T wave shocks and explains the upper and lower limits of vulnerability. Furthermore, we suggested that the same mechanism might be responsible for defibrillation failure. The aim of this study was to experimentally support this hypothesis. METHODS AND RESULTS: We used the voltage-sensitive dye di-4-ANEPPS and fast imaging to assess electrical activity in Langendorff-perfused rabbit hearts. Ventricular arrhythmias were induced by monophasic shocks applied during T wave. Three types of defibrillation shocks (n = 79) were delivered from an intravenous right ventricular electrode: monophasic (8 msec), optimal biphasic (8/8 msec, 2/1 leading-edge voltage ratio), and nonoptimal biphasic (8/8 msec, 1/1 leading-edge voltage ratio). We found that a monophasic shock extinguished arrhythmic pattern of electrical activity via a virtual electrode polarization effect. However, the virtual electrode polarization was likely to produce phase singularities, leading to another arrhythmia and defibrillation failure. Nonoptimal biphasic shocks produced similar effects. Optimal biphasic shocks were successful because the first phase of the shock erased the arrhythmia via the virtual electrodes effect, whereas the second phase canceled the virtual electrodes, eliminating the substrate for phase singularities and arrhythmia resulting from them. CONCLUSION: Our data provide the first experimental support of the hypothesis implicating virtual electrode-induced phase singularity in defibrillation failure in the Langendorff-perfused rabbit heart. Optimal biphasic shock has a higher defibrillation efficacy because it does not produce virtual electrode-induced phase singularities. |
| | |
Authors:
|
I R Efimov; Y Cheng; Y Yamanouchi; P J Tchou |
Related Documents
:
|
7394538 - Radionuclide evaluation of cardiac trauma. 14597928 - Influence of thrombolytic therapy, with or without intra-aortic balloon counterpulsatio... 17079038 - Acute reversible cardiomyopathy with cardiogenic shock in a patient with addisonian cri... 8911848 - Early graft failure after heart transplantation due to coronary artery embolization wit... 19175358 - Transient limb ischaemia remotely preconditions through a humoral mechanism acting dire... 12665878 - Thrombolytic therapy for acute ischemic stroke : issues and answers. |
Publication Detail:
|
Type: In Vitro; 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: 11 ISSN: 1045-3873 ISO Abbreviation: J. Cardiovasc. Electrophysiol. Publication Date: 2000 Aug |
Date Detail:
|
Created Date: 2000-12-11 Completed Date: 2000-12-22 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 9010756 Medline TA: J Cardiovasc Electrophysiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 861-8 Citation Subset: IM |
Affiliation:
|
Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195, USA. efimov@ieee.org |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Arrhythmias, Cardiac / etiology, physiopathology, therapy Electric Countershock / adverse effects, instrumentation*, standards* Electrodes* Electrophysiology Female Fluorescent Dyes Heart / physiopathology Male Perfusion Pyridinium Compounds Rabbits Treatment Failure Treatment Outcome User-Computer Interface* |
| Grant Support | |
ID/Acronym/Agency:
|
R01-HL59464/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Fluorescent Dyes; 0/Pyridinium Compounds; 90134-00-2/1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Simultaneous occurrence of atrial fibrillation and atrial flutter.
Next Document: Spatially distributed dominant excitation frequencies reveal hidden organization in atrial fibrillat...