| Shock-induced figure-of-eight reentry in the isolated rabbit heart. | |
| | |
MedLine Citation:
|
PMID: 10576949 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The patterns of transmembrane potential on the whole heart during and immediately after fibrillation-inducing shocks are unknown. To study arrhythmia induction, we recorded transmembrane activity from the anterior and posterior epicardial surface of the isolated rabbit heart simultaneously using 2 charge-coupled device cameras (32,512 pixels, 480 frames/second). Isolated hearts were paced from the apex at a cycle length of 250 ms. Two shock coils positioned inside the right ventricle (-) and atop the left atrium (+) delivered shocks at 3 strengths (0.75, 1.5, and 2.25 A) and 6 coupling intervals (130 to 230 ms). The patterns of depolarization and repolarization were similar, as is evident in the uniformity of action potential duration at 75% repolarization (131.4¿8.3 ms). At short coupling intervals (<180 ms), shocks hyperpolarized a large portion of the ventricles and produced a pair of counterrotating waves, one on each side of the heart. The first beat after the shock was reentrant in 90% of short coupling interval episodes. At long coupling intervals (>180 ms), increasingly stronger shocks depolarized an increasingly larger portion of the heart. The first beat after the shock was reentrant in 18% of long coupling interval episodes. Arrhythmias were most often induced at short coupling intervals (98%) than at long coupling intervals (35%). The effect and outcome of the shock were related to the refractory state of the heart at the time of the shock. Hyperpolarization occurred at short coupling intervals, whereas depolarization occurred at long coupling intervals. Consistent with the "critical point" hypothesis, increasing shock strength and coupling interval moved the location where reentry formed (away from the shock electrode and pacing electrode, respectively). |
| | |
Authors:
|
I Banville; R A Gray; R E Ideker; W M Smith |
Related Documents
:
|
15013709 - Ischemia, reperfusion, and the role of surgery in the treatment of cardiogenic shock se... 2393609 - Measurement of cardiac reserve in cardiogenic shock: implications for prognosis and man... 7967019 - "myocardial stunning"-like phenomenon during a crisis of pheochromocytoma. 2647229 - Myocardial dysfunction in sepsis. 19468019 - Intractable cardiogenic shock in stress cardiomyopathy with left ventricular outflow tr... 12053679 - Acute cardiogenic shock immediately after successful intervention for failed thrombolysis. 8623109 - Clinical relevance of intracranial microembolic signals in patients with left ventricul... 2468139 - Reliability of transesophageal pacing in the assessment of sinus node function in patie... 22115649 - Double-edged role of the cxcl12/cxcr4 axis in experimental myocardial infarction. |
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: 85 ISSN: 1524-4571 ISO Abbreviation: Circ. Res. Publication Date: 1999 Oct |
Date Detail:
|
Created Date: 1999-11-04 Completed Date: 1999-11-04 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0047103 Medline TA: Circ Res Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 742-52 Citation Subset: IM |
Affiliation:
|
Department of Biomedical Engineering, Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Ala, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Action Potentials Animals Cardiac Pacing, Artificial Electrophysiology Electroshock* Rabbits Reaction Time Reproducibility of Results Ventricular Fibrillation / etiology*, physiopathology* |
| Grant Support | |
ID/Acronym/Agency:
|
HL-28429/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Egocentric localization: visually directed alignment to projected head landmarks in binocular and mo...
Next Document: Single-plate Molteno implants in complicated glaucomas: results, survival rates, and complications.