| The influence of elevated Mg2+ concentrations on cardiac electrophysiologic parameters. | |
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MedLine Citation:
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PMID: 2484855 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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This study was performed to evaluate the direct effects of magnesium ions on cardiac conduction velocities and on refractoriness using a modified Langendorff perfusion system and a special ECG recording and stimulation technique. An increase of the MG2+ concentration to 2.3 mM had no detectable effects. Higher concentrations of up to 4.6 mM decreased the spontaneous sinus rate and the conduction velocity through the AV node and the His bundle in a concentration-dependent manner. During stimulation with premature beats, in the presence of 4.6 mM of Mg2+, the effective and relative refractory periods (ERP, RRP) of sinoatrial, AV nodal, and His bundle conduction and the ERP of the ventricular myocardium were significantly prolonged, whereas the ERP of the atrial myocardium remained unaffected. The refractoriness of sinoatrial, AV nodal, and His bundle conduction, and of the ventricular myocardium, were also prolonged during pacing with a stepwise increased pacing rate. These observations suggest a marked rate-dependent inhibitory effect of magnesium on the refractoriness of the His-bundle conduction and of the ventricular myocardium, which might be an important factor in the antiarrhythmic effectiveness of magnesium in ventricular tachyarrhythmias. |
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Authors:
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G Stark; U Stark; E Pilger; K Hönigl; H Bertuch; H A Tritthart |
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Publication Detail:
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Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy Volume: 3 ISSN: 0920-3206 ISO Abbreviation: Cardiovasc Drugs Ther Publication Date: 1989 Apr |
Date Detail:
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Created Date: 1991-03-28 Completed Date: 1991-03-28 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8712220 Medline TA: Cardiovasc Drugs Ther Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 183-9 Citation Subset: IM |
Affiliation:
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Department of Internal Medicine, Karl-Franzens-University of Graz, School of Medicine, Austria. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Atrioventricular Node / drug effects Bundle of His / drug effects Cardiac Complexes, Premature / physiopathology Electric Stimulation Electrocardiography Electrophysiology Female Guinea Pigs Heart / drug effects* Heart Conduction System / drug effects Magnesium / pharmacology* Male Refractory Period, Electrophysiological / drug effects Sinoatrial Node / drug effects |
| Chemical | |
Reg. No./Substance:
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7439-95-4/Magnesium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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