| Acute effects of intravenous magnesium on ventricular refractoriness and monophasic action potential duration in humans. | |
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MedLine Citation:
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PMID: 10540920 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The objective of this study was to examine the antiarrhythmic mechanisms of magnesium (Mg). The 12 patients who were selected for the study were given 12 mmol Mg sulphate followed by an infusion of 8 mmol/h. Ventricular effective refractory period (VERP). monophasic action potential duration at 50% and 90% repolarization during spontaneous rhythm (MAPD50, MAPD90) and atrial pacing at a cycle length of 600 ms (MAPD(50)600, MAPD(90)600) were measured before and after the intervention. Plasma magnesium concentration rose from 0.83 +/- 0.05 to 1.85 +/- 0.24 mmol/l (p < 0.001). Shortening of MAPD(50) (250 +/- 45 vs 240 +/- 46 ms; p < 0.05), MAPD(90) (294 +/- 42 vs 283 +/- 41 ms; p < 0.05) and shortening of sinus cycle length (SCL) (783 +/- 153 vs 742 +/- 160 ms; p < 0.01) were detected. During controlled cycle length, magnesium decreased MAPD(50)600 (230 +/- 28 vs 221 +/- 28 ms; p < 0.01), MAPD(90)600 (274 +/- 25 vs 261 +/- 29 ms; p < 0.01) and VERP (247 +/- 25 vs 241 +/- 21 ms: p < 0.05). QRS duration, QT interval and blood pressure remained unchanged. The change in SCL correlated with the change in MAPD(50) (r = 0.58; p < 0.05) and MAPD(90) (r = 0.55; p = 0.06 ) but not with MAPD(50)600, MAPD(90)600 or VERP. Magnesium acutely shortens ventricular monophasic action potential duration and refractoriness. This effect is partly mediated by mechanisms that increase heart rate. The reductions might bring salutary effects in arrhythmias evoked by prolonged repolarization. |
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Authors:
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H J Parikka; L K Toivonen |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Scandinavian cardiovascular journal : SCJ Volume: 33 ISSN: 1401-7431 ISO Abbreviation: Scand. Cardiovasc. J. Publication Date: 1999 |
Date Detail:
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Created Date: 1999-11-17 Completed Date: 1999-11-17 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 9708377 Medline TA: Scand Cardiovasc J Country: NORWAY |
Other Details:
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Languages: eng Pagination: 300-5 Citation Subset: IM |
Affiliation:
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Department of Medicine, Helsinki University Central Hospital, Finland. hannu.parikka@huch.fi |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials
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drug effects*,
physiology Adolescent Adult Aged Female Heart Conduction System / drug effects* Humans Infusions, Intravenous Magnesium / administration & dosage, pharmacology* Male Middle Aged |
| 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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