Document Detail


Diltiazem does not increase ventricular fibrillation threshold during hypothermia.
MedLine Citation:
PMID:  7572017     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study was designed to investigate whether the calcium channel blocker diltiazem affects the threshold for ventricular fibrillation during hypothermia in dogs. Ten dogs were cooled from 37 to 25 degrees C and rewarmed to 37 degrees C. The threshold for ventricular fibrillation was determined at body temperatures 37, 34, 31, 28 and 25 degrees C by programmed electrical stimulation using a stimulation protocol which involved application of maximal five extrastimuli. At 25 degrees C, six dogs were given an i.v. bolus dose of 100 micrograms.kg-1 followed by a continuous infusion of 100 micrograms.kg-1.h-1 of diltiazem hydrochloride. The other four dogs, were given no drugs at 25 degrees C and served as a control group. The dogs were rewarmed, and the stimulus protocol was performed at the same temperatures as during cooling. Cooling from 37 to 25 degrees C reduced the threshold for ventricular fibrillation in both groups. Heart rate were reduced, monophasic action potential duration at the apex and base of the heart increased from 167 +/- 5 ms to 469 +/- 17 ms and from 164 +/- 5 ms to 466 +/- 17 ms, respectively, when the temperature was reduced. The ventricular effective refractory period increased from 176 +/- 9 ms at 37 degrees C to 472 +/- 15 ms at 25 degrees C. Cooling increased QRS time on the ECG from 55 +/- 4 ms to 138 +/- 13 ms. Addition of diltiazem at 25 degrees C did not affect the threshold for ventricular fibrillation during rewarming. Further, diltiazem at 25 degrees C did not affect the heart rate or refractoriness.(ABSTRACT TRUNCATED AT 250 WORDS)
Authors:
H Bjørnstad; D Jenssen; E Mortensen
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta anaesthesiologica Scandinavica     Volume:  39     ISSN:  0001-5172     ISO Abbreviation:  Acta Anaesthesiol Scand     Publication Date:  1995 Jul 
Date Detail:
Created Date:  1995-11-09     Completed Date:  1995-11-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370270     Medline TA:  Acta Anaesthesiol Scand     Country:  DENMARK    
Other Details:
Languages:  eng     Pagination:  659-65     Citation Subset:  IM    
Affiliation:
Department of Medical Physiology, University of Tromsø, Norway.
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MeSH Terms
Descriptor/Qualifier:
Action Potentials / drug effects
Animals
Calcium Channel Blockers / pharmacology*
Diltiazem / pharmacology*
Dogs
Electrocardiography
Female
Heart Rate / drug effects
Hypothermia, Induced / adverse effects*
Male
Refractory Period, Electrophysiological / drug effects
Ventricular Fibrillation / prevention & control*
Chemical
Reg. No./Substance:
0/Calcium Channel Blockers; 42399-41-7/Diltiazem

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


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