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Negru AG, Pastorcici A, Crisan S, Cismaru G, Popescu FG, Luca CT. The Role of Hypomagnesemia in Cardiac Arrhythmias: A Clinical Perspective. Biomedicines 2022; 10:2356. [PMID: 36289616 PMCID: PMC9598104 DOI: 10.3390/biomedicines10102356] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/03/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
The importance of magnesium (Mg2+), a micronutrient implicated in maintaining and establishing a normal heart rhythm, is still controversial. It is known that magnesium is the cofactor of 600 and the activator of another 200 enzymatic reactions in the human organism. Hypomagnesemia can be linked to many factors, causing disturbances in energy metabolism, ion channel exchanges, action potential alteration and myocardial cell instability, all mostly leading to ventricular arrhythmia. This review article focuses on identifying evidence-based implications of Mg2+ in cardiac arrhythmias. The main identified benefits of magnesemia correction are linked to controlling ventricular response in atrial fibrillation, decreasing the recurrence of ventricular ectopies and stopping episodes of the particular form of ventricular arrhythmia called torsade de pointes. Magnesium has also been described to have beneficial effects on the incidence of polymorphic ventricular tachycardia and supraventricular tachycardia. The implication of hypomagnesemia in the genesis of atrial fibrillation is well established; however, even if magnesium supplementation for rhythm control, cardioversion facility or cardioversion success/recurrence of AF after cardiac surgery and rate control during AF showed some benefit, it remains controversial. Although small randomised clinical trials showed a reduction in mortality when magnesium was administered to patients with acute myocardial infarction, the large randomised clinical trials failed to show any benefit of the administration of intravenous magnesium over placebo.
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Schoeller AB, Rudloff E, Waldner CL, Klose TC, Linklater AK. Preliminary evaluation of the efficacy of intravenous magnesium sulfate for the treatment of ventricular arrhythmias in 16 dogs. J Vet Emerg Crit Care (San Antonio) 2020; 30:687-692. [PMID: 33037777 DOI: 10.1111/vec.13004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 12/30/2018] [Accepted: 01/13/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To evaluate the efficacy of IV magnesium sulfate in decreasing the number of ventricular ectopic beats or convert ventricular tachyarrhythmia to sinus rhythm in dogs. DESIGN Prospective, observational feasibility study. SETTING Private referral center. ANIMALS Sixteen client-owned dogs exhibiting 1 or more of the following: (1) sustained or paroxysmal ventricular tachycardia (heart rate > 180/min), (2) single or multiform ventricular complexes at > 60 ectopies/min. INTERVENTIONS Pretreatment (T1) blood creatinine and electrolyte concentrations were measured. A 60-second lead II ECG strip and systolic arterial blood pressure (SABP) were recorded. Magnesium sulfate 0.1 mmol/kg (0.2 mEq/kg) was administered IV over 5 minutes. Five minutes after completion of the magnesium sulfate injection (T2), electrolyte concentrations were measured again. A second 60-second lead II ECG strip and SABP were recorded. The number of ectopic ventricular and supraventricular beats (sinus beats) that occurred in 60 seconds during the T1 and T2 ECG recordings was compared. T1 and T2 electrolytes and SABP were also compared. RESULTS There was an increase in the ionized magnesium concentration, a decrease in the heart rate and the number of ventricular ectopic beats, and an increase in the number of supraventricular beats at T2. Two dogs converted to a sinus rhythm at T2 that was not sustained. CONCLUSIONS Intravenous administration of 0.1 mmol/kg (0.2 mEq/kg) magnesium sulfate in dogs with ventricular ectopy decreased the number of ventricular beats and heart rate. However, a specific conclusion regarding the use of magnesium sulfate as a first-line therapy for dogs with ventricular tachyarrhythmias at the investigated dose cannot be made.
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Affiliation(s)
| | - Elke Rudloff
- Lakeshore Veterinary Specialists, Glendale, Wisconsin
| | - Cheryl L Waldner
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Tyler C Klose
- Lakeshore Veterinary Specialists, Glendale, Wisconsin
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Liu M, Dudley SC. Magnesium, Oxidative Stress, Inflammation, and Cardiovascular Disease. Antioxidants (Basel) 2020; 9:E907. [PMID: 32977544 PMCID: PMC7598282 DOI: 10.3390/antiox9100907] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Hypomagnesemia is commonly observed in heart failure, diabetes mellitus, hypertension, and cardiovascular diseases. Low serum magnesium (Mg) is a predictor for cardiovascular and all-cause mortality and treating Mg deficiency may help prevent cardiovascular disease. In this review, we discuss the possible mechanisms by which Mg deficiency plays detrimental roles in cardiovascular diseases and review the results of clinical trials of Mg supplementation for heart failure, arrhythmias and other cardiovascular diseases.
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Affiliation(s)
- Man Liu
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Samuel C. Dudley
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
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Baker WL. Treating arrhythmias with adjunctive magnesium: identifying future research directions. Eur Heart J Cardiovasc Pharmacother 2016:pvw028. [DOI: 10.1093/ehjcvp/pvw028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Abstract
Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4–6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4–6-month space missions.
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Li EC, Esterly JS, Pohl S, Scott SD, McBride BF. Drug-Induced QT-Interval Prolongation: Considerations for Clinicians. Pharmacotherapy 2010; 30:684-701. [DOI: 10.1592/phco.30.7.684] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Hanci V, Ayoğlu H, Yurtlu S, Yildirim N, Okyay RD, Erdoğan G, Sayin E, Turan IO. An Evaluation of P Wave Dispersion, QT, Corrected QT and Corrected QT Dispersion Intervals on the Electrocardiograms of Malnourished Adults. Anaesth Intensive Care 2010; 38:122-7. [DOI: 10.1177/0310057x1003800120] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The aim of our study was to investigate P wave dispersion (Pwd), QT, corrected QT (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) intervals in subjects with malnutrition diagnosed in the pre-anaesthetic assessment, compared to those without malnutrition. A total of 76 adult patients were included. Main diagnoses, anthropometric measurement, body mass index, electrocardiogram and serum sodium, potassium, chloride, magnesium and calcium levels were recorded for all patients. Pwd, QT and QTd intervals were measured on all electrocardiogram records and QTc and QTcd intervals determined with the Bazett formula. Protein-energy malnutrition was diagnosed with the nutritional risk index. No statistically significant difference was found between the age, gender and malignant cancer diagnosis rates between patients with malnutrition (group M) and those not suffering from malnutrition (group N) (P >0.05). Serum albumin, total protein, potassium, calcium, magnesium and chloride values of group M were found to be significantly lower than group N (P <0.05). In group M, Pwd, QT, QTc, QTd and QTcd intervals were significantly longer than in group N (P <0.001). Patients diagnosed with malnutrition during pre-anaesthetic assessment had significantly longer Pwd, QTc and QTcd interval durations than the control group. We attribute such extended Pwd, QTc and QTcd durations in these patients to malnutrition and malnutrition-related electrolyte imbalance.
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Affiliation(s)
- V. Hanci
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - H. Ayoğlu
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - S. Yurtlu
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - N. Yildirim
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
- Associate Professor Doctor, Department of Cardiology
| | - R. D. Okyay
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - G. Erdoğan
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - E. Sayin
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
| | - I. O. Turan
- Department of Anesthesiology and Reanimation, Zonguldak Karaelmas University, School of Medicine, Zonguldak, Turkey
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Abstract
Pediatric cardiomyopathies are heterogeneous groups of serious disorders of the heart muscle and are responsible for significant morbidity and mortality among children who have the disease. While enormous improvements have been made in the treatment and survival of children with congenital heart disease, parallel strides have not been made in the outcomes for cardiomyopathies. Thus, ancillary therapies, such as nutrition and nutritional interventions, that may not cure but may potentially improve cardiac function and quality of life, are imperative to consider in children with all types of cardiomyopathy. Growth failure is one of the most significant clinical problems of children with cardiomyopathy with nearly one-third of children with this disorder manifesting some degree of growth failure during the course of their illness. Optimal intake of macronutrients can help improve cardiac function. In addition, several specific nutrients have been shown to correct myocardial abnormalities that often occur with cardiomyopathy and heart failure. In particular, antioxidants that can protect against free radical damage that often occurs in heart failure and nutrients that augment myocardial energy production are important therapies that have been explored more in adults with cardiomyopathy than in the pediatric population. Future research directions should pay particular attention to the effect of overall nutrition and specific nutritional therapies on clinical outcomes and quality of life in children with pediatric cardiomyopathy.
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Affiliation(s)
- Tracie L Miller
- Division of Pediatric Clinical Research, Department of Pediatrics, Miller School of Medicine, University of Miami, Miami, FL
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Abstract
Physicians' use of micronutrients to improve symptoms or outcomes in chronic illness has until recently been guided by limited data on the actions of individual agents in vitro or in animal studies. However several recently published clinical trials have provided information about which groups of patients are likely to benefit from which combination of micronutrients. Patients with chronic cardiac failure (CCF), particularly elderly individuals, have several reasons to be deficient in micronutrients including reduced intake, impaired gastrointestinal absorption and increased losses on the background of increased utilisation due for example to increased oxidative stress. Studies of nutritional supplementation in CCF patients have usually concentrated on specific agents. However given that many micronutrients have synergistic influences upon metabolic processes this strategy might merely lead to a shifting of a limiting step. Rather, a strategy of increasing the availability of multiple agents at once might be more logical. The aim of this article is to briefly review the experimental rationale for each of the micronutrients of potential benefit in chronic heart failure and examine the current clinical trial evidence supporting their use.
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Affiliation(s)
- Klaus K Witte
- Mount Sinai Hospital, University Health Network, 600 University Avenue, Toronto, ON, M5J 1X5, Canada.
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Averbukh Z, Berman S, Efrati S, Manevits E, Rosenberg R, Malcev E, Galperin E, Weissgarten J. Blockade of renin-angiotensin system reduces QT dispersion and improves intracellular Ca/Mg status in hemodialysis patients. Nephron Clin Pract 2006; 104:c176-84. [PMID: 17003569 DOI: 10.1159/000095853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 07/25/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Electrolyte impairments are common in hemodialysis (HD) patients. Consequently, QT dispersion (QTd) is prolonged, correlating with high intracellular magnesium. In patients with cardiac disorders, renin-angiotensin system (RAS) inhibition reduces QTd. AIM To compare the effects of ACE inhibition or AT-1 blockade on QTd duration and intracellular magnesium (Mg)/calcium (Ca) in peripheral blood mononuclear cells (PBMC) from chronic HD patients. METHODS 24 HD patients received cilazapril for 8 weeks and, following a 2-week withdrawal, were switched to valsartan for additional 8 weeks. QTd measurements and PBMC isolation were performed at the beginning and the end of each period. Total intracellular Ca and Mg were assessed by atomic spectrometer, and cytosolic free Ca2+ by fluorocytometer. RESULTS Both treatments significantly decreased QTd, demonstrating similar reduction magnitudes. In both groups, PBMC exhibited basally low cytosolic Ca2+ and undisturbed high transmembrane Ca2+ influx following phytohemagglutinin stimulation. Total intracellular Ca was increased, while Mg was reduced, following either treatment. The total intracellular Ca/Mg ratio inversely correlated with QTd duration. CONCLUSIONS (1) RAS inhibition reduces prolonged QTd in HD patients. (2) In PBMC from ordinarily Ca-depleted HD patients, RAS suppression brings about elevation of total intracellular Ca. (3) RAS blockade decreases high intracellular Mg in PBMC from HD patients. Consequently, the Ca/Mg ratio increases, inversely correlating with QTd reduction.
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Affiliation(s)
- Zhan Averbukh
- Nephrology Division, Assaf Harofeh Medical Center, Affiliated to Sackler Medical School, Tel Aviv University, Zerifin, Israel.
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Abstract
A novel technique, using energy dispersive X-ray microanalysis (EXAtm), for noninvasive intracellular (i.c.) measurement of magnesium [Mg2+]i has now been accomplished and proven to be a valuable tool in multiple aspects of normal as well as pathological magnesium metabolism. Since only 1% of total body Mg2+ is found in the intravascular space, serum levels of Mg2+ give little information about a patient's overall Mg2+ status with respect to this essential mineral. Using the EXAtm analysis it has shown been determined that Mg2+ levels are significantly reduced in many physiological states which may lead to serious pathological conditions [15]. Description of the methodology and examples of data as well as potential applications will focus on intracellular (i.c.) [Mg2+]i determinations obtained in cells from subjects with cardiovascular disease (CVD) syndromes related to Mg2+ deficiency. Examples of the application of EXAtm evaluation include examination of intracellular magnesium and other minerals in a wide spectrum of conditions which include cardiovascular conditions, arrhythmias, heart failure, myocardial infarction, and bypass surgery. Standardization of control values were performed at NASA.
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Affiliation(s)
- Burton B Silver
- Department of Physiology & Biophysics, University of Louisville, School of Medicine, Louisville, Kentucky, USA.
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Abstract
Atrial tachyarrhythmias, including atrial fibrillation and flutter, occur frequently. Magnesium has been studied in the early conversion and prevention of atrial tachyarrhythmias, as well as in prevention of atrial tachyarrhythmias after coronary artery bypass graft surgery. Early conversion of atrial tachyarrhythmias and control of heart rate may be greater with magnesium than with common antiarrhythmic agents. Magnesium appears to be less useful for preventing recurrent atrial tachyarrhythmias; however, discrepancies in study methodologies make interpretation of results difficult. The use of magnesium for prevention of postoperative atrial arrhythmias has produced conflicting results, likely due to differences in study design. From the limited data available, magnesium appears to have some inherent antiarrhythmic properties. Certain patient populations may derive benefit from magnesium for the treatment of atrial tachyarrhythmias. However, further study is necessary to define the role of magnesium clearly for the treatment or prevention of atrial tachyarrhythmias.
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Affiliation(s)
- Alexandria A Piotrowski
- Division of Pharmacotherapy, University of Texas Health Science Center, San Antonio, Texas, USA
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Averbukh Z, Rosenberg R, Galperin E, Berman S, Cohn M, Cohen N, Modai D, Efrati S, Weissgarten J. Cell-associated magnesium and QT dispersion in hemodialysis patients. Am J Kidney Dis 2003; 41:196-202. [PMID: 12500237 DOI: 10.1053/ajkd.2003.50004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Impaired magnesium (Mg) homeostasis has been implicated in a variety of cardiovascular disturbances, including ventricular arrhythmias and changes in the interval between the onset of wave Q to the end of wave T (QT interval) on electrocardiogram. Cardiac arrhythmias are common in patients on hemodialysis therapy. METHODS We investigated the relationship between QT interval corrected for heart rate (QTc) dispersion and Mg content in peripheral blood mononuclear cells (PBMC) of chronic hemodialysis patients treated with high-dose calcium carbonate providing Mg in excess (group I; n = 18) or low-dose calcium carbonate and smaller Mg load (group II; n = 13). RESULTS Mean Mg content in PBMC of group I patients (27.9 +/- 4.2 [SD] micromol/L/mg protein) was significantly greater than in group II patients (10.4 +/- 4.1 micromol/L/mg protein; P < 0.05) and greater in both groups than in healthy control subjects (2.75 +/- 0.6 micromol/L/mg protein; P < 0.05). Mean QTc dispersion was significantly longer (74.6 +/- 21.4 milliseconds) in group I than group II (37.8 +/- 13.1 milliseconds; P < 0.02) and longer in both groups than in controls (27.3 +/- 9.6 milliseconds; P < 0.05). After dialysis, in both groups of patients, cell-associated Mg (c-a Mg) levels and QTc dispersion were significantly greater (P < 0.05) than before dialysis started. One week after stopping calcium carbonate treatment, group 1 patients showed significant reductions in predialytic c-a Mg levels (to 19.5 +/- 9.8 micromol/L/mg protein; P < 0.05) and QTc dispersions (to 48.9 +/- 23.7 milliseconds; P < 0.05). Plasma Mg and other electrolyte concentrations prior to and during hemodialysis did not correlate with QTc dispersion. CONCLUSION Prolongation of QTc dispersion in patients on chronic hemodialysis therapy could be, at least in part, a consequence of increased concentrations of c-a Mg resulting from excess daily Mg intake.
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Affiliation(s)
- Zhan Averbukh
- Nephrology Division and Department of Medicine F, Assaf Harofeh Medical Center, Zerifin, Israel.
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Abstract
OBJECTIVE To determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium. DESIGN Quantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries. SETTING Hiroshima University Hospital a tertiary cardiology centre. PATIENTS 17 patients with angiographically normal coronary arteries. INTERVENTIONS Magnesium sulfate (MgSO(4)) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA. MAIN OUTCOME MEASURES Diameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow. RESULTS At a dose of 0.02 mmol/min, MgSO(4) did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO(4) caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p < 0.001 v baseline for all). MgSO(4) increased the changes in these parameters after the infusion of L-NMMA (p < 0.001 v baseline). CONCLUSIONS Magnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.
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Affiliation(s)
- H Teragawa
- The First Department of Internal Medicine, Hiroshima University School of Medicine, 1-2-3 Kasumi, Minamiku, Hiroshima, Japan 734-8851.
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Teragawa H, Kato M, Yamagata T, Matsuura H, Kajiyama G. Magnesium causes nitric oxide independent coronary artery vasodilation in humans. Heart 2001. [DOI: 10.1136/hrt.86.2.212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVETo determine how magnesium affects human coronary arteries and whether endothelium derived nitric oxide (EDNO) is involved in the coronary arterial response to magnesium.DESIGNQuantitative coronary angiography and Doppler flow velocity measurements were used to determine the effects of the nitric oxide synthase inhibitorNG-monomethyl-L-arginine (L-NMMA) on magnesium induced dilation of the epicardial and resistance coronary arteries.SETTINGHiroshima University Hospital a tertiary cardiology centre.PATIENTS17 patients with angiographically normal coronary arteries.INTERVENTIONSMagnesium sulfate (MgSO4) (0.02 mmol/min and 0.2 mmol/min) was infused for two minutes into the left coronary ostium before and after intracoronary infusion of L-NMMA.MAIN OUTCOME MEASURESDiameter of the proximal and distal segments of the epicardial coronary arteries and coronary blood flow.RESULTSAt a dose of 0.02 mmol/min, MgSO4 did not affect the coronary arteries. At a dose of 0.2 mmol/min, MgSO4 caused coronary artery dilation (mean (SEM) proximal diameter 3.00 (0.09) to 3.11 (0.09) mm; distal 1.64 (0.06) to 1.77 (0.07) mm) and increased coronary blood flow (79.3 (7.5) to 101.4 (9.9) ml/min, p < 0.001 vbaseline for all). MgSO4 increased the changes in these parameters after the infusion of L-NMMA (p < 0.001v baseline).CONCLUSIONSMagnesium dilates both the epicardial and resistance coronary arteries in humans. Furthermore, the coronary arterial response to magnesium is dose dependent and independent of EDNO.
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Abstract
The cause of low back pain is heterogeneous, it has been hypothesised that a latent chronic acidosis might contribute to these symptoms. It was tested whether a supplementation with alkaline minerals would influence symptoms in patients with low back pain symptoms. In an open prospective study 82 patients with chronic low back pain received daily 30 g of a lactose based alkaline multimineral supplement (Basica) over a period of 4 weeks in addition to their usual medication. Pain symptoms were quantified with the "Arhus low back pain rating scale" (ARS). Mean ARS dropped highly significant by 49% from 41 to 21 points after 4 weeks supplemention. In 76 out of 82 patients a reduction in ARS was achieved by the supplementation. Total blood buffering capacity was significantly increased from 77.69 +/- 6.79 to 80.16 +/- 5.24 mmol/L (mean +/- SEM, n = 82, p < 0.001) and also blood pH rose from 7.456 +/- 0.007 to 7.470 +/- 0.007 (mean +/- SEM, n = 75, p < 0.05). Only intracellular magnesium increased by 11% while other intracellular minerals were not significantly changed in sublingual tissue as measured with the EXA-test. Plasma concentrations of potassium, calcium, iron, copper, and zinc were within the normal range and not significantly influenced by the supplementation. Plasma magnesium was slightly reduced after the supplemenation (-3%, p < 0.05). The results show that a disturbed acid-base balance may contribute to the symptoms of low back pain. The simple and safe addition of an alkaline multimineral preparate was able to reduce the pain symptoms in these patients with chronic low back pain.
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Affiliation(s)
- J Vormann
- Institut für Prävention und Ernährung, Ismaning, Germany.
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Haigney MC, Wei S, Kääb S, Griffiths E, Berger R, Tunin R, Kass D, Fisher WG, Silver B, Silverman H. Loss of cardiac magnesium in experimental heart failure prolongs and destabilizes repolarization in dogs. J Am Coll Cardiol 1998; 31:701-6. [PMID: 9502656 DOI: 10.1016/s0735-1097(97)00524-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES We sought to determine whether heart failure results in loss of cardiac magnesium sufficient to alter cellular electrophysiology. BACKGROUND Free magnesium has numerous intracellular roles affecting metabolism, excitability and RNA synthesis. Total cardiac magnesium content is reduced in heart failure, but it is unclear whether magnesium loss is primary or iatrogenic. Furthermore, it is unknown whether free magnesium levels are affected or whether a change in free magnesium would alter cellular electrophysiology. METHODS Eight mongrel dogs underwent demand ventricular pacing (VVI) at 250 beats/min for 3 weeks to induce heart failure. Sublingual epithelial magnesium was measured before pacing and at death. Left ventricular myocytes were isolated and loaded with Mag-Indo-1 to measure free magnesium ([Mg2+]i); myocytes from eight normal dogs served as controls. To test whether changes in [Mg2+]i in this range could alter cellular repolarization, current-clamped myocytes were dialyzed with 0.5 or 1.0 mmol/liter MgCl2. RESULTS Mean sublingual epithelial magnesium fell significantly in the paced animals, from 36.9 +/- 0.5 to 33.9 +/- 0.7 mEq/liter (p < 0.01). Mean cardiac [Mg2+]i was significantly lower in the dogs with heart failure--0.49 +/- 0.06 versus 1.06 +/- 0.15 mmol/liter (p < 0.003). Time to 90% repolarization was significantly shorter in cells dialyzed with 1.0 mmol/liter compared with 0.5 mmol/liter MgCl2 in myocytes from normal dogs or dogs with heart failure (596 +/- 34 vs. 760 +/- 58 ms in normal dogs and 586 +/- 29 vs. 838 +/- 98 ms in dogs with heart failure; p < 0.05 for each). CONCLUSIONS Experimental heart failure results in both tissue and cardiac magnesium loss in the absence of drug therapy. Free cardiac magnesium is significantly reduced, possibly contributing to abnormal repolarization in heart failure.
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Affiliation(s)
- M C Haigney
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA.
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