1
|
de Kok JWTM, van Rosmalen F, Koeze J, Keus F, van Kuijk SMJ, Castela Forte J, Schnabel RM, Driessen RGH, van Herpt TTW, Sels JWEM, Bergmans DCJJ, Lexis CPH, van Doorn WPTM, Meex SJR, Xu M, Borrat X, Cavill R, van der Horst ICC, van Bussel BCT. Deep embedded clustering generalisability and adaptation for integrating mixed datatypes: two critical care cohorts. Sci Rep 2024; 14:1045. [PMID: 38200252 PMCID: PMC10781731 DOI: 10.1038/s41598-024-51699-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/08/2024] [Indexed: 01/12/2024] Open
Abstract
We validated a Deep Embedded Clustering (DEC) model and its adaptation for integrating mixed datatypes (in this study, numerical and categorical variables). Deep Embedded Clustering (DEC) is a promising technique capable of managing extensive sets of variables and non-linear relationships. Nevertheless, DEC cannot adequately handle mixed datatypes. Therefore, we adapted DEC by replacing the autoencoder with an X-shaped variational autoencoder (XVAE) and optimising hyperparameters for cluster stability. We call this model "X-DEC". We compared DEC and X-DEC by reproducing a previous study that used DEC to identify clusters in a population of intensive care patients. We assessed internal validity based on cluster stability on the development dataset. Since generalisability of clustering models has insufficiently been validated on external populations, we assessed external validity by investigating cluster generalisability onto an external validation dataset. We concluded that both DEC and X-DEC resulted in clinically recognisable and generalisable clusters, but X-DEC produced much more stable clusters.
Collapse
Affiliation(s)
- Jip W T M de Kok
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands.
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands.
| | - Frank van Rosmalen
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Jacqueline Koeze
- Department of Critical Care, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Frederik Keus
- Department of Critical Care, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Sander M J van Kuijk
- Department of Clinical Epidemiology and Medical Technical Assessment, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - José Castela Forte
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, The Netherlands
| | - Ronny M Schnabel
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
| | - Rob G H Driessen
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Thijs T W van Herpt
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Jan-Willem E M Sels
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Department of Cardiology, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Dennis C J J Bergmans
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - Chris P H Lexis
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
| | - William P T M van Doorn
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Department of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Steven J R Meex
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Department of Clinical Chemistry, Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Minnan Xu
- Takeda Pharmaceuticals, Deerfield, IL, USA
| | - Xavier Borrat
- Department of Biostatistics Harvard T.H, Chan School of Public Health, Boston, MA, USA
- Anaesthesiology and Critical Care Department, Hospital Clinic de Barcelona, Barcelona, Spain
- Medical Informatics Department, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Rachel Cavill
- Department of Advanced Computing Sciences, Maastricht University, Maastricht, The Netherlands
| | - Iwan C C van der Horst
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Bas C T van Bussel
- Department of Intensive Care Medicine, Maastricht University Medical Centre+, P. Debyelaan, 25, 6229 HX, Maastricht, The Netherlands
- Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
- Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
2
|
Soomro QH, Bansal N, Winkelmayer WC, Koplan BA, Costea AI, Roy-Chaudhury P, Tumlin JA, Kher V, Williamson DE, Pokhariyal S, McClure CK, Charytan DM. Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study. KIDNEY360 2022; 3:1871-1880. [PMID: 36514397 PMCID: PMC9717630 DOI: 10.34067/kid.0003142022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/13/2022] [Indexed: 11/06/2022]
Abstract
Background Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain. Methods The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of predialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours before an HD session. Associations with CSBA were analyzed with mixed-effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters and associations of peridialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next. Results There were 551 CSBA that occurred in the last 12 hours of the interdialytic interval preceding 100 HD sessions in 12% of patients and 1475 CSBA events in 23% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 versus 8, P=0.04). Use of dialysate sodium concentrations ≤135 (versus 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next. Conclusions Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.
Collapse
Affiliation(s)
- Qandeel H. Soomro
- Nephrology Division, Department of Medicine, NYU Langone Medical Center, New York, New York
| | - Nisha Bansal
- Division of Nephrology, Kidney Research Institute, University of Washington, Seattle, Washington
| | - Wolfgang C. Winkelmayer
- Section of Nephrology, Selzman Institute for Kidney Health, Department of Medicine, Baylor College of Medicine, Houston, Texas
- Internal Medicine/Nephrology, Emory University, Atlanta, Georgia
| | | | | | - Prabir Roy-Chaudhury
- University of North Carolina Kidney Center, Chapel Hill, North Carolina
- WG (Bill) Hefner VA Medical Center, Salisbury, North Carolina
| | - James A. Tumlin
- Georgia Nephrology Clinical Research Institute, Atlanta, Georgia
| | - Vijay Kher
- Fortis Escorts Kidney and Urology Institute, Fortis Escorts Hospital, New Delhi, India
| | | | | | | | - David M. Charytan
- Nephrology Division, Department of Medicine, NYU Langone Medical Center, New York, New York
| |
Collapse
|
3
|
Tuttle A, Fitter S, Hua H, Moussavi K. The Effects of Magnesium Coadminstration During Treatment of Hypokalemia in the Emergency Department. J Emerg Med 2022; 63:399-413. [DOI: 10.1016/j.jemermed.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/06/2022] [Accepted: 06/04/2022] [Indexed: 11/12/2022]
|
4
|
Barton CD, Pizer B, Jones C, Oni L, Pirmohamed M, Hawcutt DB. Identifying cisplatin-induced kidney damage in paediatric oncology patients. Pediatr Nephrol 2018; 33:1467-1474. [PMID: 28821959 PMCID: PMC6061670 DOI: 10.1007/s00467-017-3765-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 11/06/2022]
Abstract
Cisplatin is one chemotherapeutic agent used to treat childhood cancer in numerous treatment protocols, including as a single agent. It is likely to remain in clinical use over the long term. However, cisplatin-related toxicities, including neurotoxicity and nephrotoxicity, are common, affecting treatment, day-to-day life and survival of such children. With one in 700 young adults having survived childhood cancer, patients who have completed chemotherapy that includes cisplatin can experience long-term morbidity due to treatment-related adverse reactions. A better understanding of these toxicities is essential to facilitate prevention, surveillance and management. This review article discusses the effect of cisplatin-induced nephrotoxicity (Cis-N) in children and considers the underlying mechanisms. We focus on clinical features and identification of Cis-N (e.g. investigations and biomarkers) and the importance of magnesium homeostasis and supplementation.
Collapse
Affiliation(s)
- Chris D Barton
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Paediatric Oncology, Alder Hey Children's Hospital, Liverpool, UK
| | - Barry Pizer
- Department of Paediatric Oncology, Alder Hey Children's Hospital, Liverpool, UK
| | - Caroline Jones
- Department of Paediatric Nephrology, Alder Hey Children's Hospital, Liverpool, UK
| | - Louise Oni
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
- Department of Paediatric Nephrology, Alder Hey Children's Hospital, Liverpool, UK
| | - Munir Pirmohamed
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Daniel B Hawcutt
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
- NIHR Alder Hey Clinical Research Facility, University of Liverpool, Liverpool, UK.
| |
Collapse
|
5
|
Fernando H, Adams N, Mitra B. Review article: The utility of troponin and other investigations in patients presenting to the emergency department with supraventricular tachycardia. Emerg Med Australas 2018; 31:35-42. [PMID: 29752780 DOI: 10.1111/1742-6723.12971] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 02/16/2018] [Accepted: 02/20/2018] [Indexed: 11/30/2022]
Abstract
Patients with supraventricular tachycardia commonly present to the ED. There is a lack of consensus regarding assessment of these patients. Our aim was to determine the utility of troponin and four other investigations (full blood examination, electrolyte levels, thyroid function tests and chest X-rays) commonly requested for these patients. MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (January 1992-March 2017) were searched for randomised controlled trials and observational studies (of sample size greater than 10). Our search strategy yielded no randomised controlled trials and seven observational studies with significant statistical heterogeneity among selected studies (I2 87.3%, P < 0.001). Included studies investigated a total of 1155 patients. All studies reported on the utility of troponin testing in this patient population. The pooled proportion of patients investigated with troponin was 0.66 (95% confidence interval 0.44-0.88). The pooled proportion of positive troponin tests was 0.32 (95% confidence interval 0.23-0.41). Only one study reported on the utility of the remaining four investigations with abnormal results as follows: thyroid stimulating hormone 14%, haemoglobin 6%, white cell count 19% and chest X-ray 22%. Investigations are commonly requested for patients presenting with supraventricular tachycardia. Troponin testing is commonly performed with a high proportion of positive findings although these results did not appear to be associated with major adverse cardiac events. Heterogeneity among studies and low levels of evidence precluded conclusions on full blood examinations, electrolyte levels, thyroid testing and utility of chest X-rays in this patient population.
Collapse
Affiliation(s)
- Harith Fernando
- National Trauma Research Institute, The Alfred Hospital, Melbourne, Victoria, Australia.,The University of Melbourne, Melbourne, Victoria, Australia
| | - Nicholas Adams
- Emergency and Trauma Centre, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Biswadev Mitra
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
6
|
de Francisco AL, Varas J, Ramos R, Merello JI, Canaud B, Stuard S, Pascual J, Aljama P. Proton Pump Inhibitor Usage and the Risk of Mortality in Hemodialysis Patients. Kidney Int Rep 2017; 3:374-384. [PMID: 29725641 PMCID: PMC5932134 DOI: 10.1016/j.ekir.2017.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/11/2017] [Accepted: 11/06/2017] [Indexed: 12/11/2022] Open
Abstract
Introduction Long-term inappropriate proton pump inhibitors use (PPIs) is a matter of concern because of the risks associated with their long-term use in older patients with chronic conditions. The risk of PPI treatment in hemodialysis patients remains unexplored. Methods We assessed the relationship between the use of PPIs and the risk of death in hemodialysis patients throughout a retrospective multicenter propensity score–matched study. Information about demographic, hemodialysis treatment, laboratory data, and concomitant medication was obtained from the EuCliD database (Fresenius Medical Care). We studied 1776 hemodialysis patients on PPI therapy compared to 466 patients not receiving PPIs. The resulting population comprising 2 groups of 410 matched patients was studied. Results PPI use was associated with hypomagnesemia (Mg <1.8 mg/dl (0.75 mmol/l); odds ratio [OR] = 2.70, 95% confidence interval [CI] = 1.38−5.27, P < 0.01). The exposure to PPIs in the full patient cohort was identified as an independent predictor for all-cause mortality in both univariate (HR = 3.16, 95% CI = 1.69–5.90, P < 0.01) and multivariate (HR = 2.70, 95% CI = 1.38–5.27, P < 0.01) Cox regression models. Moreover PPI use was identified as a predictor of CV mortality (HR = 1.51, 95% CI = 1.05−2.20, P = 0.03) Of the 820 patients matched throughout the propensity score analysis, the hazard ratios for all-cause mortality (HR = 1.412, 95% CI = 1.04–1.93, P = 0.03) and CV mortality (HR = 1.67, 95% CI = 1.03−2.71, P = 0.04) were higher among patients on PPIs versus those not on PPIs. Conclusion The study data suggest that the PPI treatment should be regularly monitored and prescribed only when indicated.
Collapse
Affiliation(s)
- Angel L.M. de Francisco
- Servicio de Nefrología H. U. Valdecilla, Santander, Spain
- Correspondence: Angel L.M. de Francisco, Department of Nephrology, Valdecilla Universitary Hospital, Avenida Valdecilla sn, 39008 Santander, Spain.
| | - Javier Varas
- Dirección Médica, Fresenius Medical Care, Madrid, Spain
| | - Rosa Ramos
- Dirección Médica, Fresenius Medical Care, Madrid, Spain
| | | | | | | | - Julio Pascual
- Servicio de Nefrologia, Hospital del Mar, Barcelona, Spain
| | - Pedro Aljama
- Servicio de Nefrología, Hospital Universitario Reina Sofía, Córdoba, Spain
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Universidad de Córdoba, Córdoba, Spain
- RedInRen, Instituto de Salud Carlos III, Córdoba, Spain
| | | |
Collapse
|
7
|
Pun PH, Middleton JP. Dialysate Potassium, Dialysate Magnesium, and Hemodialysis Risk. J Am Soc Nephrol 2017; 28:3441-3451. [PMID: 28993507 DOI: 10.1681/asn.2017060640] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
One of the fundamental goals of the hemodialysis prescription is to maintain serum potassium levels within a narrow normal range during both the intradialytic and interdialytic intervals. Considering the extraordinarily high rate of cardiovascular mortality in the hemodialysis population, clinicians are obligated to explore whether factors related to dialytic potassium removal can be modified to improve clinical outcomes. Observational studies and circumstantial evidence suggest that extreme concentrations of serum and dialysate potassium can trigger cardiac arrest. In this review, we provide an overview of factors affecting overall potassium balance and factors modulating potassium dialysate fluxes in dialysis, and we review data linking serum and dialysate potassium concentrations with arrhythmias, cardiovascular events, and mortality. We explore potential interactions between serum and dialysate magnesium levels and risks associated with dialysate potassium levels. Finally, we conclude with proposed dialytic and novel nondialytic approaches to optimize outcomes related to potassium homeostasis in patients on hemodialysis. Dialysis clinicians need to consider changes in the overall clinical scenario when choosing dialysate potassium concentrations, and an effective change in practice will require more frequent serum potassium monitoring and responsive dialysis care teams.
Collapse
Affiliation(s)
- Patrick H Pun
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina; and .,Duke Clinical Research Institute, Durham, North Carolina
| | - John P Middleton
- Division of Nephrology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina; and
| |
Collapse
|
8
|
Ashok A, Cabalag M, Taylor DM. Usefulness of laboratory and radiological investigations in the management of supraventricular tachycardia. Emerg Med Australas 2017; 29:394-399. [PMID: 28320069 DOI: 10.1111/1742-6723.12766] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 12/18/2016] [Accepted: 01/29/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Although ED patients presenting with supraventricular tachycardia (SVT) are commonly investigated, the value of these investigations has been questioned. We aimed to determine the frequency and utility of investigations in patients with SVT. METHODS We undertook an explicit retrospective medical record audit of patients with SVT who presented to a single ED (January 2004 to June 2014). Data on demographics, presenting complaints, investigations and outcomes were extracted. The outcomes were nature and utility of investigations. RESULTS A total of 633 patients were enrolled (mean [SD] age 55.4 [17.7] years, 62% female). Laboratory investigations were common: electrolytes (83.7% of patients), full blood count (81.2%), magnesium (57.5%), calcium (39.3%) and thyroid function (30.3%). These investigations revealed many mildly abnormal results but resulted in electrolyte supplementation in only 19 patients: eight with mild hypokalaemia (potassium 3.0-3.5 mmol/L) and 11 with mild hypomagnesia (magnesium 0.49-1.1 mmol/L). Troponin was ordered for 302 (47.7%) patients, many of whom had no history or risk factors for cardiac disease, or ischaemic symptoms associated with their SVT. The troponin was normal, mildly and moderately elevated in 65.2, 24.5 and 10.2% of cases, respectively. Only seven (1.1%) patients were diagnosed with acute myocardial ischemia. Although 190 (30.0%) patients had a chest X-ray (CXR), it was normal in 78.4% of cases. All CXR abnormalities were incidental and not relevant to the immediate ED management. CONCLUSION Patients with uncomplicated SVT are over-investigated. Guidelines for ED SVT investigation are recommended. Further research is recommended to determine the indications for each investigation in the setting of SVT.
Collapse
Affiliation(s)
| | - Miguel Cabalag
- Department of Surgery, Austin Hospital, Melbourne, Victoria, Australia
| | - David McD Taylor
- Emergency Department, Austin Hospital, Melbourne, Victoria, Australia.,Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
9
|
Abstract
Although the following text will focus on magnesium in disease, its role in healthy subjects during physical exercise when used as a supplement to enhance performance is also noteworthy. Low serum magnesium levels are associated with metabolic syndrome, Type 2 diabetes mellitus (T2DM) and hypertension; consequently, some individuals benefit from magnesium supplementation: increasing magnesium consumption appears to prevent high blood pressure, and higher serum magnesium levels are associated with a lower risk of developing a metabolic syndrome. There are, however, conflicting study results regarding magnesium administration with myocardial infarction with and without reperfusion therapy. There was a long controversy as to whether or not magnesium should be given as a first-line medication. As the most recent trials have not shown any difference in outcome, intravenous magnesium cannot be recommended in patients with myocardial infarction today. However, magnesium has its indication in patients with torsade de pointes and has been given successfully to patients with digoxin-induced arrhythmia or life-threatening ventricular arrhythmias. Magnesium sulphate as an intravenous infusion also has an important established therapeutic role in pregnant women with pre-eclampsia as it decreases the risk of eclamptic seizures by half compared with placebo.
Collapse
Affiliation(s)
- Helmut Geiger
- Klinikum der J.W. Goethe-Universität, Medizinische Klinik III/Nephrologie, Frankfurt/Main, Germany
| | - Christoph Wanner
- Universitätsklinik Würzburg, Medizinische Klinik und Poliklinik I, Würzburg, Germany
| |
Collapse
|
10
|
Shimaoka T, Wang Y, Morishima M, Miyamoto S, Ono K. Hypomagnesemic down-regulation of L-type Ca(2+) channel in cardiomyocyte as an arrhythmogenic substrate in rats. ACTA ACUST UNITED AC 2015; 22:87-93. [PMID: 25701242 DOI: 10.1016/j.pathophys.2015.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 01/28/2015] [Accepted: 01/30/2015] [Indexed: 11/27/2022]
Abstract
The present study was designed to investigate the effect of magnesium (Mg) depletion on the expression of voltage-gated calcium (Ca(2+)) channels and Ca(2+) currents in the heart and thereby on hypomagnesemic arrhythmogenesis in adult male rats. Male Wistar rats were fed an Mg-free diet or a normal diet for up to 16 weeks. Serum Mg concentrations were significantly reduced at week 4 or later with an Mg-free diet, which experimentally represents hypomagnesemia. Myocardial Mg contents were also reduced at week 16 accompanied by myocardial hypertrophy. Telemetric ECG recordings revealed a long-term changes of ECG parameters in hypomagnesemic rats; RR shortening, QT prolongation and appreciable PR prolongation. At the same time, hypomagnesemic rats demonstrate various bradycardiac arrhythmias including ventricular premature beats, atrioventricular blocks and sinus arrest, which were never recoded in rats fed by a normal diet. Electrophysiological studies elucidated that the L-type Ca(2+) channel current was decreased in Mg-deficient cardiomyocytes, and these findings were consistent with down-regulation of CaV1.2-mRNA but not in levels of CaV1.3, CaV3.1 or CaV3.2. These findings provide novel insights into hypomagnesemic electrophysiological disorders in the heart, and should be considered when assessing the design of effective antiarrhythmic treatments in patients with hypomagnesemia.
Collapse
Affiliation(s)
- Toru Shimaoka
- Department of Pathophysiology, Oita University School of Medicine, Yufu, Oita 879-5593, Japan; Department of Cardiovascular Surgery, Oita University School of Medicine, Yufu, Oita 879-5593, Japan
| | - Yan Wang
- Department of Pathophysiology, Oita University School of Medicine, Yufu, Oita 879-5593, Japan
| | - Masaki Morishima
- Department of Pathophysiology, Oita University School of Medicine, Yufu, Oita 879-5593, Japan
| | - Shinji Miyamoto
- Department of Cardiovascular Surgery, Oita University School of Medicine, Yufu, Oita 879-5593, Japan
| | - Katsushige Ono
- Department of Pathophysiology, Oita University School of Medicine, Yufu, Oita 879-5593, Japan.
| |
Collapse
|
11
|
Tsai TF, Browning AC, Rutledge J. Global T-wave inversions with isolated hypomagnesemia. J Emerg Med 2013; 45:e107-e111. [PMID: 23896055 DOI: 10.1016/j.jemermed.2013.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 03/21/2013] [Accepted: 04/30/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND The physiological actions of magnesium within the cardiac conduction system and myocytes have yet to be fully elucidated. Because concurrent hypocalcemia or hypokalemia were also present in previous human reports, specific electrocardiographic effects of isolated hypomagnesemia have not been clearly delineated. OBJECTIVE We report a case in which dynamic electrocardiogram (ECG) changes were demonstrated in isolated hypomagnesemia. CASE REPORT A 37-year-old man with history of heavy alcohol use was admitted for syncope. The ECG showed global T-wave inversions with prolonged corrected QT (QTc) duration on ECG. Extensive work-up including cardiac catheterization was unremarkable. His serum magnesium was noted to be low at 1.1 mg/dL, and his serum calcium and potassium were within normal limits. The patient received magnesium infusion with subsequent ECGs showing resolution of his global T-wave inversions and prolonged QTc. CONCLUSION This case is unique because it reports dynamic ECG changes in a patient with isolated hypomagnesemia. Although isolated hypomagnesemia is commonly believed to result in dysrhythmia, we were unaware of any previous cases of ECG abnormalities in humans. Clinically, we advise checking serum magnesium and correcting hypomagnesemia when prolonged QTc duration and global T-wave inversions are seen on ECG.
Collapse
Affiliation(s)
- Ting F Tsai
- Department of Cardiovascular Medicine, University of California-Davis Medical Center, Sacramento, California
| | | | | |
Collapse
|
12
|
Reed BN, Zhang S, Marron JS, Montague D. Comparison of intravenous and oral magnesium replacement in hospitalized patients with cardiovascular disease. Am J Health Syst Pharm 2013; 69:1212-7. [PMID: 22761075 DOI: 10.2146/ajhp110574] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE The results of an investigation of serum magnesium concentrations (SMCs) after i.v. versus oral delivery of magnesium in cardiovascular critical care are presented. METHODS A retrospective case review was conducted to compare the net gain of magnesium after i.v. (n = 188) or oral (n = 164) magnesium therapy for the prevention of ventricular fibrillation and arrhythmias in patients hospitalized for serious cardiovascular disorders, as determined by assessing SMCs. The primary study outcome was the change from baseline SMC values 6-24 hours after the completion of magnesium courses; secondary outcomes included the impact of renal impairment, concomitant medication use, and other clinical variables on SMC changes. RESULTS Although consistent elevations in SMC were produced by oral magnesium delivery, i.v. administration resulted in greater and more rapid elevations relative to baseline SMC. The degree of change in SMC was significantly influenced by the timing of SMC measurement after a magnesium course, by renal function, and by concomitant use of i.v. loop diuretics. CONCLUSION A comparison of 24-hour courses of magnesium replacement therapy showed that magnesium sulfate 2 g i.v. was associated with larger changes in SMC than magnesium oxide 800, 1200, or 1600 mg orally when the baseline SMC was 1.4-1.8 mg/dL. At baseline SMCs of 1.4-1.8 mg/dL, oral magnesium oxide provided a consistent median increase in SMC of 0.1 mg/dL. The change in the number of bowel movements did not differ significantly between courses of i.v. magnesium sulfate and oral magnesium oxide.
Collapse
Affiliation(s)
- Brent N Reed
- Department of Pharmacy, University of North Carolina Hospitals & Clinics, 101 Manning Drive, CB #7600, Chapel Hill, NC 27514, USA.
| | | | | | | |
Collapse
|
13
|
Del Gobbo LC, Song Y, Poirier P, Dewailly E, Elin RJ, Egeland GM. Low serum magnesium concentrations are associated with a high prevalence of premature ventricular complexes in obese adults with type 2 diabetes. Cardiovasc Diabetol 2012; 11:23. [PMID: 22405520 PMCID: PMC3337820 DOI: 10.1186/1475-2840-11-23] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 03/09/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Premature ventricular complexes (PVC) predict cardiovascular mortality among several adult populations. Increased arrhythmia prevalence has been reported during controlled magnesium (Mg) depletion studies in adults. We thus hypothesized that serum magnesium (sMg) concentrations are inversely associated with the prevalence of PVC in adults at high cardiovascular risk. METHODS Anthropometric, demographic and lifestyle characteristics were assessed in 750 Cree adults, aged > 18 yrs, who participated in an age-stratified, cross-sectional health survey in Quebec, Canada. Holter electrocardiograms recorded heart rate variability and cardiac arrhythmias for two consecutive hours. Multivariate logistic regression was used to evaluate the associations between sMg and PVC. RESULTS PVC prevalence in adults with hypomagnesemia (sMg ≤ 0.70 mmol/L) was more than twice that of adults without hypomagnesemia (50% vs. 21%, p = 0.015); results were similar when adults with cardiovascular disease history were excluded. All hypomagnesemic adults with PVC had type 2 diabetes (T2DM). Prevalence of PVC declined across the sMg concentration gradient in adults with T2DM only (p < 0.001 for linear trend). In multivariate logistic regressions adjusted for age, sex, community, body mass index, smoking, physical activity, alcohol consumption, kidney disease, antihypertensive and cholesterol lowering drug use, and blood docosahexaenoic acid concentrations, the odds ratio of PVC among T2DM subjects with sMg > 0.70 mmol/L was 0.24 (95% CI: 0.06-0.98) p = 0.046 compared to those with sMg ≤ 0.70 mmol/L. CONCLUSIONS sMg concentrations were inversely associated with the prevalence of PVC in patients with T2DM in a dose response manner, indicating that suboptimal sMg may be a contributor to arrhythmias among patients with T2DM.
Collapse
Affiliation(s)
- Liana C Del Gobbo
- School of Dietetics & Human Nutrition, McGill University, 21,111 Lakeshore Road, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.
| | | | | | | | | | | |
Collapse
|
14
|
Morgan RA, Raftery AG, Cripps P, Senior JM, McGowan CM. The prevalence and nature of cardiac arrhythmias in horses following general anaesthesia and surgery. Acta Vet Scand 2011; 53:62. [PMID: 22112936 PMCID: PMC3269988 DOI: 10.1186/1751-0147-53-62] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 11/23/2011] [Indexed: 11/10/2022] Open
Abstract
Background The prevalence and nature of arrhythmias in horses following general anaesthesia and surgery is poorly documented. It has been proposed that horses undergoing emergency surgery for gastrointestinal disorders may be at particular risk of developing arrhythmias. Our primary objective was to determine the prevalence and nature of arrhythmias in horses following anaesthesia in a clinical setting and to establish if there was a difference in the prevalence of arrhythmias between horses with and without gastrointestinal disease undergoing surgery. Our secondary objective was to assess selected available risk factors for association with the development of arrhythmias following anaesthesia and surgery. Methods Horses with evidence of gastrointestinal disease undergoing an exploratory laparotomy and horses with no evidence of gastrointestinal disease undergoing orthopaedic surgery between September 2009 and January 2011 were recruited prospectively. A telemetric electrocardiogram (ECG) was fitted to each horse following recovery from anaesthesia and left in place for 24 hours. Selected electrolytes were measured before, during and after surgery and data was extracted from clinical records for analysis. Recorded ECGs were analysed and the arrhythmias characterised. Multivariable logistic regression was used to identify risk factors associated with the development of arrhythmias. Results Sixty-seven horses with gastrointestinal disease and 37 without gastrointestinal disease were recruited. Arrhythmias were very common during the post-operative period in both groups of horses. Supra-ventricular and bradyarrhythmias predominated in both groups. There were no significant differences in prevalence of any type of arrhythmias between the horses with or without gastrointestinal disease. Post-operative tachycardia and sodium derangements were associated with the development of any type of arrhythmia. Conclusions This is the first study to report the prevalence of arrhythmias in horses during the post-operative period in a clinical setting. This study shows that arrhythmias are very common in horses following surgery. It showed no differences between those horses with or without gastrointestinal disease. Arrhythmias occurring in horses during the post-anaesthetic period require further investigation.
Collapse
|
15
|
Musso CG. Magnesium metabolism in health and disease. Int Urol Nephrol 2009; 41:357-62. [PMID: 19274487 DOI: 10.1007/s11255-009-9548-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Accepted: 02/17/2009] [Indexed: 12/21/2022]
Abstract
Magnesium (Mg) is the main intracellular divalent cation, and under basal conditions the small intestine absorbs 30-50% of its intake. Normal serum Mg ranges between 1.7-2.3 mg/dl (0.75-0.95 mmol/l), at any age. Even though eighty percent of serum Mg is filtered at the glomerulus, only 3% of it is finally excreted in the urine. Altered magnesium balance can be found in diabetes mellitus, chronic renal failure, nephrolithiasis, osteoporosis, aplastic osteopathy, and heart and vascular disease. Three physiopathologic mechanisms can induce Mg deficiency: reduced intestinal absorption, increased urinary losses, or intracellular shift of this cation. Intravenous or oral Mg repletion is the main treatment, and potassium-sparing diuretics may also induce renal Mg saving. Because the kidney has a very large capacity for Mg excretion, hypermagnesemia usually occurs in the setting of renal insufficiency and excessive Mg intake. Body excretion of Mg can be enhanced by use of saline diuresis, furosemide, or dialysis depending on the clinical situation.
Collapse
Affiliation(s)
- Carlos G Musso
- Nephrology Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
16
|
Abstract
Nearly 50 medications have been implicated as inducing hypomagnesaemia, sometimes based on insufficient data regarding clinical significance and frequency of occurrence. In fact, clinical effects attributed to hypomagnaesemia have been reported in only 17 of these drugs. A considerable amount of literature relating to individual drugs has been published, yet a comprehensive overview of this issue is not available and the hypomagnesaemic effect of a drug could be either overemphasised or under-rated. In addition, there are neither guidelines regarding treatment, prevention and monitoring of drug-induced hypomagnesaemia nor agreement as to what serum level of magnesium may actually be defined as 'hypomagnesaemia'. By compiling data from published papers, electronic databases, textbooks and product information leaflets, we attempted to assess the clinical significance of hypomagnesaemia induced by each drug. A practical approach for managing drug-induced hypomagnesaemia, incorporating both published literature and personal experience of the physician, is proposed. When drugs classified as inducing 'significant' hypomagnesaemia (cisplatin, amphotericin B, ciclosporin) are administered, routine magnesium monitoring is warranted, preventive treatment should be considered and treatment of hypomagnesaemia should be initiated with or without overt clinical manifestations. In drugs belonging to the 'potentially significant' category, among which are amikacin, gentamicin, laxatives, pentamidine, tobramycin, tacrolimus and carboplatin, magnesium monitoring is justified when either of the following occurs: clinical manifestations are apparent; persistent hypokalaemia, hypocalcaemia or alkalosis are present; other precipitating factors for hypomagnesaemia coexist; or treatment is with more than one potentially hypomagnesaemic drug. No preventive treatment is required and treatment should be initiated only if hypomagnesaemia is accompanied by symptoms or clinically significant relevant laboratory findings. In those drugs whose hypomagnesaemic effect is labelled as 'questionable', including furosemide and hydrochlorothiazide, routine monitoring and treatment are not required.
Collapse
Affiliation(s)
- Jacob Atsmon
- Clinical Pharmacology Unit, Tel Aviv Sourasky Medical Center, Te Aviv, Israel.
| | | |
Collapse
|
17
|
Stambuk-Giljanović N, Stambuk D. Information subsystem of the Ca/Mg ratio as a database for studying its influence on human health. J Med Syst 2005; 29:581-8. [PMID: 16235810 DOI: 10.1007/s10916-005-6125-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Dalmatia is situated in the Dinaric karst in Southern Croatia. It is characterized by insufficient quantities of water during the summer months and a relatively excessive amount of rainfall during the winter and spring months. Other hydrographic characteristics of Dinaric carst include scarce and long surface streamflows with a few tributaries with changeable capacities, a small number of springs, and a relatively great number of submarine springs along the coast. The water supply and health-care institutions are especially interested in observing and monitoring water quality. A relational database has been developed for carrying out chemical analyses expressed by the Ca/Mg ratio since it is necessary to organize and integrate a large number of analytical and ecological health data. The database can serve as a methodological platform for the study of environmental factors influencing human health. The prototype database consists of data obtained by investigations which have been conducted by the water Examination Department of the Public Health Institute of the Split Dalmatian county (Croatia) University of Split Medical School. The database currently contains more than 2500 data.
Collapse
Affiliation(s)
- Nives Stambuk-Giljanović
- Public Health Institute of the Split-Dalmatian County, University of Split Medical School, Hrvatska, Republic of Croatia.
| | | |
Collapse
|
18
|
Picolos MK, Orlander PR. Calcium Carbonate Toxicity: The Updated Milk-Alkali Syndrome; Report of 3 Cases and Review of the Literature. Endocr Pract 2005; 11:272-80. [PMID: 16006300 DOI: 10.4158/ep.11.4.272] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To describe 3 patients with calcium carbonate-induced hypercalcemia and gain insights into the cause and management of the milk-alkali syndrome. METHODS We report the clinical and laboratory data in 3 patients who presented with severe hypercalcemia (corrected serum calcium > or = 14 mg/dL) and review the pertinent literature on milk-alkali syndrome. RESULTS The 3 patients had acute renal insufficiency, relative metabolic alkalosis, and low parathyroid hormone (PTH), PTH-related peptide, and 1,25-dihydroxyvitamin D concentrations. No malignant lesion was found. Treatment included aggressive hydration and varied amounts of furosemide. The 2 patients with the higher serum calcium concentrations received pamidronate intravenously (60 and 30 mg, respectively), which caused severe hypocalcemia. Of the 3 patients, 2 were ingesting acceptable doses of elemental calcium (1 g and 2 g daily, respectively) in the form of calcium carbonate. In addition to our highlighted cases, we review the history, classification, pathophysiologic features, and treatment of milk-alkali syndrome and summarize the cases reported from early 1995 to November 2003. CONCLUSION Milk-alkali syndrome may be a common cause of unexplained hypercalcemia and can be precipitated by small amounts of orally ingested calcium carbonate in susceptible persons. Treatment with hydration, furosemide, and discontinuation of the calcium and vitamin D source is adequate. Pamidronate treatment is associated with considerable risk for hypocalcemia, even in cases of initially severe hypercalcemia.
Collapse
Affiliation(s)
- Michalis K Picolos
- Division of Endocrinology, Diabetes and Metabolism, The University of Texas-Houston Medical School, Houston, Texas 77030, USA
| | | |
Collapse
|
19
|
Crawford MW, Ho DS, Shams M, Gow R. Magnesium deficiency alters the threshold for epinephrine-induced arrhythmias during halothane or sevoflurane anesthesia in the rat. J Cardiothorac Vasc Anesth 2004; 18:313-6. [PMID: 15232811 DOI: 10.1053/j.jvca.2004.03.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To determine the effect of chronic magnesium (Mg2+) deficiency on the relative arrhythmogenicity of halothane and sevoflurane in the rat. DESIGN Prospective, randomized, nonblinded study. SETTING University laboratory. PARTICIPANTS Male Sprague-Dawley rats (n = 48). INTERVENTIONS Rats were maintained on a Mg2+-deficient or control diet for 14 days, at which time they were anesthetized with halothane or sevoflurane, a tracheostomy was performed, and the lungs were ventilated to maintain normocapnia. Catheters were inserted into a femoral vein and carotid artery. Lead II of the electrocardiogram was monitored to determine the threshold for epinephrine-induced arrhythmias. MEASUREMENTS AND MAIN RESULTS Chronic Mg2+ deficiency significantly decreased the dose of epinephrine required for arrhythmias (ADE). The reduction in the ADE was approximately one third during halothane anesthesia (p < 0.05) and one fifth during sevoflurane anesthesia (p < 0.001). Infusion of magnesium sulphate completely reversed the reduction in ADE. In normomagnesemic rats, the halothane ADE was significantly less than the sevoflurane ADE (mean difference = 6.0 microg/kg, 95% confidence interval of the difference = 3.6 to 8.4 microg/kg) (p < 0.005). Mg2+ deficiency significantly attenuated the difference between the halothane ADE and the sevoflurane ADE (mean difference in the Mg2+-deficient group = 0.6 microg/kg, 95% confidence interval of the difference = -0.2 to 1.5 microg/kg). CONCLUSION Chronic Mg2+ deficiency decreased the threshold for epinephrine-induced arrhythmias and attenuated differences between the arrhythmogenic potential of halothane and sevoflurane, suggesting that arrhythmias are as likely to develop with sevoflurane as with halothane in the presence of coexisting magnesium deficiency and elevated catecholamines.
Collapse
Affiliation(s)
- Mark W Crawford
- Department of Anesthesia, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
| | | | | | | |
Collapse
|
20
|
|
21
|
|
22
|
Seaberg DC, Menegazzi JJ, Check B, MacLeod BA, Yealy DM. Use of a cardiocerebral-protective drug cocktail prior to countershock in a porcine model of prolonged ventricular fibrillation. Resuscitation 2001; 51:301-8. [PMID: 11738783 DOI: 10.1016/s0300-9572(01)00426-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES This was the third study in a series exploring whether the use of combination pharmacotherapy with delayed countershock would produce higher rates of return of spontaneous circulation (ROSC) and one-hour survival when compared with standard advanced cardiac life support (ACLS) therapy in prolonged ventricular fibrillation (VF). METHODS Twenty-four female, mixed-breed, domestic swine (ranging in mass from 22 to 25 kg) were used in this prospective, blinded, randomized, experimental trial. Animals were sedated (ketamine/xylazine), anesthetized (alpha-chloralose), paralyzed (pancuronium), mechanically ventilated with room air, and monitored with electrocardiography, arterial pressure, and Swan-Ganz catheters. VF was induced with a 3 s, 60 Hz, 100 mA transthoracic shock, and remained untreated for 8 min. One minute of basic life support followed (standardized by use of a mechanical device). At 9 min, animals were treated with one of three regimes: Group 1, cardiocerebral-protective cocktail (antioxidant U-74389G (3.0 mg/kg), epinephrine (0.2 mg/kg), lidocaine (1.0 mg/kg), bretylium (5.0 mg/kg), magnesium (2.0 g), and propranolol (1.0 mg)); Group 2, magnesium (2.0 g); and Group 3, standard ACLS. Groups 1 and 2 received drugs at minute nine (first countershock at minute 11), while Group 3 received first countershock at minute nine. Data were analyzed with two-tailed Fisher's exact tests. RESULTS ROSC was achieved in Group 1, 7/7 (100%); Group 2, 3/9 (33%, P versus Group 1=0.01); and Group 3, 3/8 (38%; P versus Group 1=0.02). One-hour survival was attained in Group 1, 7/7 (100%); Group 2, 3/9 (33%; P versus Group 1=0.01), and Group 3, 1/8 (13%; P versus Group 1=0.001). CONCLUSIONS Combination pharmacotherapy with a cardiocerebral-protective drug cocktail prior to countershock produced superior rates of ROSC and one-hour survival when compared with singular drug therapy (Group 2) and standard ACLS (Group 3) in this porcine model of prolonged VF.
Collapse
Affiliation(s)
- D C Seaberg
- Department of Emergency Medicine, University of Florida Health Sciences Center, PO Box 100186, Gainesville, FL 32610-0186, USA.
| | | | | | | | | |
Collapse
|
23
|
Abstract
Intracellular magnesium is an important modulator of calcium and potassium channels in cardiac myocytes. Hypomagnesemia is common in hospitalized patients and may contribute significantly to cardiac morbidity and mortality, particularly in states associated with myocardial ischemia. Therefore, it is important to maintain the plasma magnesium concentration within the normal range in asymptomatic patients and in patients with cardiac disease as prophylaxis against the occurrence of significant arrhythmias.
Collapse
Affiliation(s)
- M S Agus
- Division of Pediatric Critical Care Medicine, MassGeneral Hospital for Children, Boston, Massachusetts, USA
| | | |
Collapse
|
24
|
Tomiyasu T, Chishaki A, Nakamura M. Magnesium deficiency in adult rats promotes the induction of ventricular tachycardia by the administration of epinephrine. Heart Vessels 1999; 13:122-31. [PMID: 10328182 DOI: 10.1007/bf01747829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effects of magnesium deficiency on epinephrine-induced ventricular tachyarrhythmia were investigated in adult rats. Forty-two adult Wistar rats were fed a magnesium-deficient diet while 30 rats were fed a standard diet for 20 days. The plasma magnesium concentration was lower in the magnesium-deficient rats (0.22+/-0.01 mmol/l) than in the control rats (0.76+/-0.03 mmol/l, P < 0.001). Using a telemetry system, electrocardiograms and arterial blood pressure were recorded on a polygraph in an unrestrained condition. Epinephrine was infused intravenously starting at 5 microg/kg per minute. The QT interval was prolonged to 50+/-1 ms in the magnesium-deficient rats compared with 44+/-1 ms in the control rats (P < 0.001). Before the administration of epinephrine, no ventricular tachyarrhythmias or seizures were found in either the control or the magnesium-deficient rats. The incidence of epinephrine-induced sustained ventricular tachycardia (VT) was higher in the magnesium-deficient rats (86%) than in the control rats (43%, P < 0.01). However, this VT did not result in sudden death. Seizures always preceded death in both the magnesium-deficient and control rats while the arrhythmias observed immediately before death were mainly bradyarrhythmias. The present study in an adult rat magnesium-deficient model revealed that magnesium deficiency enhances the susceptibility to epinephrine-induced ventricular tachyarrhythmias.
Collapse
Affiliation(s)
- T Tomiyasu
- The Graduate School of Health and Nutrition Sciences, Nakamura-Gakuen University, Fukuoka, Japan
| | | | | |
Collapse
|
25
|
White CM, Xie J, Chow MS, Kluger J. Prophylactic magnesium to decrease the arrhythmogenic potential of class III antiarrhythmic agents in a rabbit model. Pharmacotherapy 1999; 19:635-40. [PMID: 10331827 DOI: 10.1592/phco.19.8.635.31528] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We assessed the prophylactic effect of intravenous magnesium sulfate on the occurrence of torsades de pointes and early after-depolarizations, and on the QT interval (QTc) in an established rabbit model. Ten rabbits were given intravenous methoxamine to slow their heart rates. After 12 minutes five animals received a 60-mg/kg bolus and continuous infusion of magnesium 0.6 mg/kg/minute, and five received equivolume normal saline concurrently with the class III antiarrhythmic agent clofilium 5 mg/kg over 30 minutes. Electrocardiogram lead II and the monophasic action potential were recorded continuously throughout the experiment. The magnesium group experienced significantly less torsades de pointes and early after-depolarizations than the normal saline group (1/5 and 5/5 both parameters, respectively, p=0.048). There were no differences between groups in QT or QTc interval at baseline or at maximum QT or QTc prolongation. Magnesium decreases the occurrence of torsades de pointes without affecting the QT or QTc interval but does decrease the occurrence of early after-depolarizations. These findings must be validated in human studies.
Collapse
Affiliation(s)
- C M White
- University of Connecticut School of Pharmacy, Storrs, USA
| | | | | | | |
Collapse
|
26
|
Khanna C, Lund EM, Raffe M, Armstrong PJ. Hypomagnesemia in 188 dogs: a hospital population-based prevalence study. J Vet Intern Med 1998; 12:304-9. [PMID: 9686391 DOI: 10.1111/j.1939-1676.1998.tb02126.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Magnesium is a divalent cation involved in more than 300 metabolic processes. Magnesium acts as an intracellular regulator of most energy-demanding pathways. Clinical investigation in the human medical field has determined risk factors for hypomagnesemia and its relationship to a number of disease processes. Experimental studies have established the effects of hypomagnesemia in dogs, but little is known of its prevalence, risk factors, or clinical associations in a hospital population of dogs. To study the prevalence, risk factors, and clinical associations of hypomagnesemia in dogs, a retrospective cross-sectional study of dogs admitted to the University of Minnesota Veterinary Teaching Hospital over a 2.5-year period was undertaken. The prevalence of hypomagnesemia in the study population was 6.1% (188 of 3,102 dogs). Using both categorical and continuous variables in a univariate analysis, significant associations with hypomagnesemia were identified and used to construct a multivariate analysis of the relative risk of hypomagnesemia. Results from evaluation of 3,102 dogs indicate that the most significant predictors of hypomagnesemia were albumin (P < or = .0001; odds ratio [OR] = 0.2), potassium (P < or = .0001; OR = 0.5), total CO2 (P < or = .05; OR = 0.9), and blood urea nitrogen concentrations (P < .0001; OR = 0.9), a diagnosis of cardiovascular disease (P < .02; OR = 1.9); and being a Collie (P < .02; OR = 3.9) or German Shepherd Dog (P < .002; OR = 2.2). These results can be used to better understand and predict hypomagnesemia in dogs.
Collapse
Affiliation(s)
- C Khanna
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, USA.
| | | | | | | |
Collapse
|
27
|
Abstract
Electrolyte balance has been regarded as a factor important to cardiovascular stability, particularly in congestive heart failure. Among the common electrolytes, the significance of magnesium has been debated because of difficulty in accurate measurement and other associated factors, including other electrolyte abnormalities. The serum magnesium level represents < 1% of total body stores and does not reflect total-body magnesium concentration, a clinical situation very similar to that of serum potassium. Magnesium is important as a cofactor in several enzymatic reactions contributing to stable cardiovascular hemodynamics and electrophysiologic functioning. Its deficiency is common and can be associated with risk factors and complications of heart failure. Typical therapy for heart failure (digoxin, diuretic agents, and ACE inhibitors) are influenced by or associated with significant alteration in magnesium balance. Magnesium therapy, both for deficiency replacement and in higher pharmacologic doses, has been beneficial in improving hemodynamics and in treating arrhythmias. Magnesium toxicity rarely occurs except in patients with renal dysfunction. In conclusion, the intricate role of magnesium on a biochemical and cellular level in cardiac cells is crucial in maintaining stable cardiovascular hemodynamics and electrophysiologic function. In patients with congestive heart failure, the presence of adequate total-body magnesium stores serve as an important prognostic indicator because of an amelioration of arrhythmias, digitalis toxicity, and hemodynamic abnormalities.
Collapse
Affiliation(s)
- S Douban
- Department of Medicine, University of California, Irvine Medical Center, Orange 92668-3298, USA
| | | | | | | |
Collapse
|
28
|
Fiset C, Kargacin ME, Kondo CS, Lester WM, Duff HJ. Hypomagnesemia: characterization of a model of sudden cardiac death. J Am Coll Cardiol 1996; 27:1771-6. [PMID: 8636567 DOI: 10.1016/0735-1097(96)00089-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVES We sought to compare the incidence of sudden death in rats treated with magnesium-deficient and control diets and to address the electrophysiologic characteristics associated with these end points. BACKGROUND Although magnesium deficiency is associated with an increased incidence of sudden cardiac death in patients, there has been no clear cause and effect relation because of a number of covariables, including diuretic use, hypokalemia, digitalis use and left ventricular dysfunction. METHODS Hypomagnesemic rats and their paired control rats underwent in vivo electrophysiologic studies and measurements of the total calcium and magnesium content of their cardiac ventricles RESULTS Serum magnesium levels were 0.5 +/- 0.3 mEq/liter (mean +/- SD) in hypomagnesemic animals and 1.2 +/- 0.9 mEq/liter in control animals. A modest but significant prolongation of the repolarization time was seen at the apical epicardial site (83 +/- 8 ms in hypomagnesemic rats vs. 68 +/- 13 ms in control rats, p < 0.05), but not at the other sites studied. Bradyarrhythmias and tachyarrhythmias were observed in 82% of the hypomagnesemic rats during the in vivo electrophysiologic studies, compared with 0% in the control group. During these studies, sudden, unexpected asystolic deaths were observed in 4 of 11 hypomagnesemic rats and 0 of 8 control rats. Polymorphic nonsustained ventricular tachycardia was provoked by rapid pacing in 5 to 11 hypomagnesemic rats and 0 of 8 control rats. Three of six hypomagnesemic rats exposed to auditory stimuli developed seizures, followed immediately by sudden deaths-two due to asystole and one due to ventricular fibrillation-although no end points occurred in the control animals. CONCLUSIONS In this model, magnesium deficiency results in sudden cardiac death. The presence of startle induction of sudden death preceded by seizures suggests that sudden cardiac death results from a neurologic trigger.
Collapse
Affiliation(s)
- C Fiset
- Cardiovascular Research Group, University of Calgary, Alberta, Canada
| | | | | | | | | |
Collapse
|
29
|
Hunt N, Stern TA. The association between intravenous haloperidol and Torsades de Pointes. Three cases and a literature review. PSYCHOSOMATICS 1995; 36:541-9. [PMID: 7501784 DOI: 10.1016/s0033-3182(95)71609-7] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Torsades de Pointes (TDP) is a potentially malignant ventricular arrhythmia that often has a drug-induced origin. Oral, but not intravenous, haloperidol has been generally associated with this arrhythmia. The authors detail three patient cases of TDP that occurred while the patients were receiving intravenous haloperidol. The authors discuss the known risk factors for the development of TDP and review the literature on ventricular arrhythmias associated with haloperidol use.
Collapse
Affiliation(s)
- N Hunt
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, USA
| | | |
Collapse
|
30
|
Denison H, Jern S, Jagenburg R, Wendestam C, Wallerstedt S. Influence of increased adrenergic activity and magnesium depletion on cardiac rhythm in alcohol withdrawal. Heart 1994; 72:554-60. [PMID: 7857739 PMCID: PMC1025642 DOI: 10.1136/hrt.72.6.554] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE To investigate the prevalence of arrhythmias in alcoholic men during detoxification and its relation to neuroendocrine activation and electrolyte disturbances. DESIGN Consecutive case-control study. SETTING Primary and secondary care, detoxification ward. PATIENTS AND CONTROLS 19 otherwise healthy alcoholic men (DSM-III-R) with withdrawal symptoms necessitating detoxification in hospital. 19 age matched, healthy non-alcoholic men as controls for Holter recordings. INTERVENTIONS Treatment with chlomethiazole; additional treatment with carbamazepine in patients with previous seizures. MAIN OUTCOME MEASURES Computer based analyses of mean heart rate and arrhythmias from 24 hour Holter recordings, 24 hour urinary excretion of adrenaline and noradrenaline, magnesium retention measured by means of intravenous loading test, and serum concentrations of electrolytes. RESULTS The 24 hour mean heart rate was higher in the alcoholic men (97.4 beats/minute, 95% confidence interval (CI) 91.2 to 103.6) than in the controls (69.6 beats/minute, 95% CI 65.4 to 73.8, P < 0.001). However, there was no difference in diurnal heart rate variation. The prevalence of premature supraventricular depolarisations was lower in the alcoholic men (P < 0.05). Neither atrial fibrillation nor malignant ventricular arrhythmias occurred. The sinus tachycardia in the alcoholic men correlated with the concomitant urinary excretion of catecholamines (P < 0.05). The mean serum magnesium concentration was 0.78 mmol/l (95% CI 0.73 to 0.83) in the alcoholic men and 0.83 mmol/l (95% CI 0.81 to 0.85) in a reference population of 55 men aged 40. Magnesium depletion (defined as magnesium retention > 30%) was detected in 10 alcoholic men (53%). Three alcoholic men had serum potassium concentrations < or = 3.3 mmol/l on admission. CONCLUSION Increased adrenergic activity, magnesium depletion, and hypokalaemia are often seen after heavy drinking, but in alcoholic men without clinical heart disease these changes were not accompanied by arrhythmias other than sinus tachycardia during detoxification in hospital.
Collapse
Affiliation(s)
- H Denison
- Department of Medicine, Ostra Hospital, University of Gothenburg, Sweden
| | | | | | | | | |
Collapse
|
31
|
Toto KH, Yucha CB. Magnesium: Homeostasis, Imbalances, and Therapeutic Uses. Crit Care Nurs Clin North Am 1994. [DOI: 10.1016/s0899-5885(18)30448-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
32
|
Abstract
Clinical studies on the use of magnesium in acute myocardial infarction have yielded contradictory results. While the exact reasons for these discrepancies are unclear, it appears that the timing of magnesium administration is crucial to the success or failure of therapy. Although some studies have shown a significant reduction in the odds of death with this agent, the exact reasons underlying this possible benefit are not yet fully understood. A reduction in arrhythmias, inhibition of thrombus generation, changes in coronary and peripheral hemodynamics, and the limitation of ischemic damage and reperfusion injury have been inferred as possible mechanisms. IV magnesium is inexpensive and easy to administer, and has minimal side effects. While further research on magnesium therapy in ischemic states is warranted, the early use of IV magnesium should be considered in selected patients with suspected acute myocardial infarction.
Collapse
Affiliation(s)
- C M Heesch
- Cardiac Catheterization Laboratory, University of Texas Southwestern
| | | |
Collapse
|
33
|
Weinreich T, Huynh U, Zitta S, Binder D, Gantenbein H, Binswanger U. Peritoneal Dialysate Magnesium how Low is Safe? Perit Dial Int 1994. [DOI: 10.1177/089686089401400229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Th. Weinreich
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| | - U. Huynh
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| | - S. Zitta
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| | - D. Binder
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| | - H. Gantenbein
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| | - U. Binswanger
- Universitätsspital Zurich Department of Internal Medicine/Nephrology 8091 Zurich, Switzerland
| |
Collapse
|
34
|
Eichhorn EJ, Tandon PK, DiBianco R, Timmis GC, Fenster PE, Shannon J, Packer M. Clinical and prognostic significance of serum magnesium concentration in patients with severe chronic congestive heart failure: the PROMISE Study. J Am Coll Cardiol 1993; 21:634-40. [PMID: 8436744 DOI: 10.1016/0735-1097(93)90095-i] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVES The aim of this study was to determine the prognostic significance of alterations in serum magnesium in patients with moderate to severe congestive heart failure. BACKGROUND Reductions in serum magnesium have been postulated to play a role in promoting arrhythmias and to have an adverse impact on survival in congestive heart failure, although support for this postulate is lacking. METHODS Serum magnesium levels were measured in 1,068 patients enrolled in a survival study of class III or IV heart failure at the time of double-blind randomization to milrinone, a phosphodiesterase inhibitor, or placebo. All patients received conventional therapy with digoxin, diuretic drugs and a converting enzyme inhibitor throughout the trial. The median follow-up period was 6.1 months (range 1 day to 20 months). RESULTS Patients with high serum magnesium (defined as > or = 1.9 mEq/liter, n = 242) were less likely to survive than were patients with a normal magnesium level (n = 627) (p < 0.05, risk ratio = 1.41). Patients with a low magnesium level (defined as < or = 1.5 mEq/liter, n = 199) had no difference in survival compared with the group with a normal magnesium level (p = NS, risk ratio = 0.89). At baseline, the patients in the high magnesium group were older and had more severe functional and renal impairment. An analysis after adjustment for these variables demonstrated no difference in survival comparing the low, normal and high magnesium groups. Although the three groups had no difference in frequency of ventricular tachycardia, length of longest run or frequency of ventricular premature beats on baseline Holter monitoring, the group with hypomagnesemia had more frequent ventricular couplets. CONCLUSIONS Serum magnesium does not appear to be an independent risk factor for either sudden death or death due to all causes in patients with moderate to severe heart failure. Hypomagnesemia is associated with an increase in the frequency of certain forms of ventricular ectopic activity, but this is not associated with an increase in clinical events. The higher mortality rate among the patients with hypermagnesemia is attributable to older age, more advanced heart failure and renal insufficiency.
Collapse
Affiliation(s)
- E J Eichhorn
- Cardiac Catheterization Laboratory, University of Texas Southwestern Medical Center, Dallas 75216
| | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
An understanding of the role of magnesium in cardiac conduction is complicated by the multiplicity of intracellular events coordinated by the magnesium ion. Several reports have cited magnesium deficiency as the cause of a variety of ventricular and supraventricular arrhythmias. On further inspection, the circumstances of each report strongly suggest the coexistence of significant potassium depletion; isolated hypomagnesemia as a cause of arrhythmia is not reported. This discussion brings together new data from basic science with that of clinical research to refute the suggestion that isolated hypomagnesemia is arrhythmogenic. However, there is sufficient evidence to indicate that hypomagnesemia will significantly exacerbate the proarrhythmic effect of hypokalemia, particularly if occurring in the presence of digoxin toxicity. Potassium and magnesium depletion are commonly concomitant, and simultaneous repletion of both ions in the presence of hypokalemia-induced arrhythmia would be both logical and effective. The beneficial effects of intravenous magnesium in the acute control of ventricular tachyarrhythmia are concluded to occur as a result of a separate antiarrhythmic action, quite independent of underlying magnesium balance.
Collapse
Affiliation(s)
- T A Millane
- Department of Cardiological Sciences, St. George's Hospital Medical School, London, England
| | | | | |
Collapse
|