title: QT interval prolongation associated with low magnesium in chronic alcoholics.
abstract: BACKGROUND
  Alcoholism is a psychoactive drug-dependence with high prevalence throughout the world. Alcoholism has already been shown to be associated with electrical heart disorders, such as QT interval prolongation. Long QT, rare among healthy individuals (0.0017-0.31%), can trigger tachyarrhythmias and sudden death and might be caused by alcohol consumption itself and the resulting hypomagnesaemia.
  
  
  METHODS
  This case-control study assessed active alcoholics and alcoholics who have been abstinent for at least seven days to compare changes in electrocardiographic, clinical and laboratory analyses among groups.
  
  
  RESULTS
  A total of 166 alcoholics were evaluated, of which 62 were active and 104 abstinent alcoholics. Long QT was more prevalent among active alcoholics compared to abstinent alcoholics (16% vs. 2%, respectively, odds ratio (OR) 9.81, p=0.011), as was hypomagnesaemia (23% vs. 10%, OR 3.11, p=0.013). Serum magnesium levels were inversely proportional to the length of the corrected QT interval among active alcoholics (β=-35.1ms, p=0.005).
  
  
  CONCLUSIONS
  Active chronic alcoholics exhibited a higher association of long QT and hypomagnesaemia. Low serum magnesium levels were predictive of QT interval prolongation. Because the above changes potentially trigger fatal arrhythmias, it is of fundamental importance to consider the diagnostic possibility by routinely requesting electrocardiograms and serum magnesium level assessment during the treatment of chronic alcoholic patients.
authors.affiliation: Cassiano Antônio Moraes University Hospital (Hospital Universitário Cassiano Antônio Moraes-HUCAM), Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Brazil. Electronic address: med.stephanie@hotmail.com.
authors.forename: Stephanie Rezende Alvarenga
authors.initials: SR
authors.lastname: Moulin
authors.affiliation: Department of Physiological Science, UFES, Brazil.
authors.forename: José Geraldo
authors.initials: JG
authors.lastname: Mill
authors.affiliation: Cassiano Antônio Moraes University Hospital (Hospital Universitário Cassiano Antônio Moraes-HUCAM), Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Brazil.
authors.forename: Werther Clay Monico
authors.initials: WC
authors.lastname: Rosa
authors.affiliation: Cassiano Antônio Moraes University Hospital (Hospital Universitário Cassiano Antônio Moraes-HUCAM), Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Brazil.
authors.forename: Silas Rubens
authors.initials: SR
authors.lastname: Hermisdorf
authors.affiliation: Cassiano Antônio Moraes University Hospital (Hospital Universitário Cassiano Antônio Moraes-HUCAM), Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Brazil.
authors.forename: Lunielle da Cruz
authors.initials: Lda C
authors.lastname: Caldeira
authors.affiliation: Cassiano Antônio Moraes University Hospital (Hospital Universitário Cassiano Antônio Moraes-HUCAM), Federal University of Espírito Santo (Universidade Federal do Espírito Santo-UFES), Brazil.
authors.forename: E Maria da Penha
authors.initials: EM
authors.lastname: Zago-Gomes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000437:Alcoholism / Q000097:blood* / Q000150:complications / Q000503:physiopathology*; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000097:blood* / Q000150:complications / Q000503:physiopathology*; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D008274:Magnesium
keywords: Alcoholism; Cardiac arrhythmias; Electrocardiogram; Long QT syndrome; Magnesium