Document Detail


Effect of adrenergic stimulation on action potential duration restitution in humans.
MedLine Citation:
PMID:  12538429     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Enhanced sympathetic activity facilitates complex ventricular arrhythmias and fibrillation. The restitution properties of action potential duration (APD) are important determinants of electrical stability in the myocardium. Steepening of the slope of APD restitution has been shown to promote wave break and ventricular fibrillation. The effect of adrenergic stimulation on APD restitution in humans is unknown. METHODS AND RESULTS: Monophasic action potentials were recorded from the right ventricular septum in 18 patients. Standard APD restitution curves were constructed at 3 basic drive cycle lengths (CLs) of 600, 500, and 400 ms under resting conditions and during infusion of isoprenaline (15 patients) or adrenaline (3 patients). The maximum slope of the restitution curves was measured by piecewise linear regression segments of sequential 40-ms ranges of diastolic intervals in steps of 10 ms. Under control conditions, the maximum slope was steeper at longer basic CLs; eg, mean values for the maximum slope were 1.053+/-0.092 at CL 600 ms and 0.711+/-0.049 at CL 400 ms (+/-SEM). Isoprenaline increased the steepness of the maximum slope of APD restitution, eg, from a maximum slope of 0.923+/-0.058 to a maximum slope of 1.202+/-0.121 at CL 500 ms. The effect of isoprenaline was greater at the shorter basic CLs. A similar overall effect was observed with adrenaline. CONCLUSIONS: The adrenergic agonists isoprenaline and adrenaline increased the steepness of the slope of the APD restitution curve in humans over a wide range of diastolic intervals. These results may relate to the known effects of adrenergic stimulation in facilitating ventricular fibrillation.
Authors:
Peter Taggart; Peter Sutton; Zaid Chalabi; Mark R Boyett; Ron Simon; Donna Elliott; Jaswinder S Gill
Related Documents :
15892539 - Hemodynamics of graded water immersion in the baboon: +gz protection potential.
10904039 - Effect of the mechanical ventilatory cycle on thermodilution right ventricular volumes ...
138489 - Pre and postoperative ventricular function in infants and children with right ventricul...
1984949 - Combined thermodilution and two-dimensional echocardiographic evaluation of right ventr...
2516699 - Evaluation and comparison of the axis of the interventricular septum by two-dimensional...
2337189 - Rapid ventricular pacing in pigs: an experimental model of congestive heart failure.
17584099 - C-reactive protein and hypertension: is there a causal relationship?
9323069 - Impact of acute mental stress on sympathetic nerve activity and regional blood flow in ...
20673309 - Relationship between an increased serum kynurenine/tryptophan ratio and atherosclerotic...
Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  Circulation     Volume:  107     ISSN:  1524-4539     ISO Abbreviation:  Circulation     Publication Date:  2003 Jan 
Date Detail:
Created Date:  2003-01-22     Completed Date:  2003-01-28     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0147763     Medline TA:  Circulation     Country:  United States    
Other Details:
Languages:  eng     Pagination:  285-9     Citation Subset:  AIM; IM    
Affiliation:
The Hatter Institute, Department of Cardiology, University College London HospitalsLondon, WC1E 6DB. peter.taggart@uclh.org.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Action Potentials / drug effects,  physiology*
Adrenergic alpha-Agonists / pharmacology*
Adrenergic beta-Agonists / pharmacology*
Adult
Aged
Diastole / physiology
Electrophysiologic Techniques, Cardiac*
Epinephrine / pharmacology
Female
Heart Ventricles / drug effects
Humans
Isoproterenol / pharmacology
Male
Middle Aged
Signal Processing, Computer-Assisted
Ventricular Function*
Chemical
Reg. No./Substance:
0/Adrenergic alpha-Agonists; 0/Adrenergic beta-Agonists; 51-43-4/Epinephrine; 7683-59-2/Isoproterenol

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


Previous Document:  Echocardiographic predictors of survival and response to early revascularization in cardiogenic shoc...
Next Document:  Vasopressor response to angiotensin II infusion in patients with chronic heart failure receiving bet...