| Assessment of global atrial fibrillation organization to optimize timing of atrial defibrillation. | |
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MedLine Citation:
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PMID: 11401945 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: We hypothesized that frequency domain analysis of a wide bipolar interatrial electrogram describes the global organization of atrial fibrillation (AF) and should vary over time. By timing shocks to periods of high organization of AF, cardioversion efficacy should improve. METHODS AND RESULTS: A total of 15 dogs (weight, 28.2+/-3.4 kg) were rapidly paced for 48 to 72 hours to induce AF. Coil electrodes with a surface area of 1.80 cm(2) were then placed in the left and right atria to form a wide bipole. Wide bipolar electrograms were digitally filtered, and a fast Fourier transform was performed over a sliding 2-s window every 0.5 s. The organization index (OI) was calculated as the ratio of the area of the dominant peak and its harmonics to the total area of the magnitude spectrum. The atrial defibrillation threshold (ADFT(50)) was determined using a 3-ms/3-ms biphasic shock and an up-down-up protocol. Additional shocks with higher and lower energies were delivered in a random sequence to develop a distribution curve. The OI varied over time, with a mean of 0.42+/-0.03, a maximum of 0.65+/-0.07, and a minimum of 0.20+/-0.06. The OI changed rapidly, with durations of high organization (OI>0.5) ranging from 1 to 5 s. The ADFT(50) for QRS complex-synchronized shocks was 183+/-56 V, versus 142+/-49 V for shocks synchronized to an OI>0.5 (P<0.001). The distribution curve shifted leftward when shocks were synchronized to an OI>0.5. CONCLUSIONS: AF signals show a high degree of variability. Shock efficacy is increased when shocks are delivered during periods of high AF organization as determined by the OI method. |
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Authors:
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T H Everett; J R Moorman; L C Kok; J G Akar; D E Haines |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Circulation Volume: 103 ISSN: 1524-4539 ISO Abbreviation: Circulation Publication Date: 2001 Jun |
Date Detail:
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Created Date: 2001-06-12 Completed Date: 2001-07-19 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0147763 Medline TA: Circulation Country: United States |
Other Details:
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Languages: eng Pagination: 2857-61 Citation Subset: AIM; IM |
Affiliation:
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Cardiovascular Division, Department of Internal Medicine, the University of Virginia Health System, Charlottesville, VA 22908, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Algorithms Animals Atrial Fibrillation / physiopathology*, therapy* Cardiac Pacing, Artificial / methods Disease Models, Animal Dogs Electric Countershock / methods* Electrocardiography Electrodes, Implanted Electrophysiologic Techniques, Cardiac Fourier Analysis Heart Conduction System / physiopathology Sensory Thresholds Signal Processing, Computer-Assisted Treatment Outcome |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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