Document Detail

Rectification of the background potassium current: a determinant of rotor dynamics in ventricular fibrillation.
MedLine Citation:
PMID:  11739288     Owner:  NLM     Status:  MEDLINE    
Ventricular fibrillation (VF) is the leading cause of sudden cardiac death. Yet, the mechanisms of VF remain elusive. Pixel-by-pixel spectral analysis of optical signals was carried out in video imaging experiments using a potentiometric dye in the Langendorff-perfused guinea pig heart. Dominant frequencies (peak with maximal power) were distributed throughout the ventricles in clearly demarcated domains. The fastest domain (25 to 32 Hz) was always on the anterior left ventricular (LV) wall and was shown to result from persistent rotor activity. Intermittent block and breakage of wavefronts at specific locations in the periphery of such rotors were responsible for the domain organization. Patch-clamping of ventricular myocytes from the LV and the right ventricle (RV) demonstrated an LV-to-RV drop in the amplitude of the outward component of the background rectifier current (I(B)). Computer simulations suggested that rotor stability in LV resulted from relatively small rectification of I(B) (presumably I(K1)), whereas instability, termination, and wavebreaks in RV were a consequence of strong rectification. This study provides new evidence in the isolated guinea pig heart that a persistent high-frequency rotor in the LV maintains VF, and that spatially distributed gradients in I(K1) density represent a robust ionic mechanism for rotor stabilization and wavefront fragmentation.
F H Samie; O Berenfeld; J Anumonwo; S F Mironov; S Udassi; J Beaumont; S Taffet; A M Pertsov; J Jalife
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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:  Circulation research     Volume:  89     ISSN:  1524-4571     ISO Abbreviation:  Circ. Res.     Publication Date:  2001 Dec 
Date Detail:
Created Date:  2001-12-12     Completed Date:  2002-01-23     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0047103     Medline TA:  Circ Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1216-23     Citation Subset:  IM    
SUNY Upstate Medical University, Syracuse, NY, USA.
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MeSH Terms
Body Surface Potential Mapping
Computer Simulation
Electrophysiologic Techniques, Cardiac
Guinea Pigs
Heart Conduction System / physiopathology*
Heart Ventricles / pathology,  physiopathology*
Models, Cardiovascular
Patch-Clamp Techniques
Potassium / metabolism*
Potassium Channels, Inwardly Rectifying / metabolism*
Ventricular Fibrillation / etiology,  pathology,  physiopathology*
Grant Support
Reg. No./Substance:
0/Potassium Channels, Inwardly Rectifying; 7440-09-7/Potassium
Comment In:
Circ Res. 2001 Dec 7;89(12):1089-91   [PMID:  11739272 ]

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

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