title: Magnesium administration may improve heart rate variability in patients with heart failure.
abstract: OBJECTIVE
  Intracellular magnesium (icMg) depletion may coexist with normomagnesemia. Mg deficiency (serum and/or intracellular) and decreased heart rate variability (HRV) are common in heart failure (HF). Since both are predictors of poor prognosis, it was of interest to evaluate the effect of Mg supplementation on HRV in patients with HF.
  
  
  RESULTS
  We investigated the effect of Mg administration on HRV in normomagnesemic patients with systolic HF. HRV, serum Mg and icMg were determined before and after 5-week 300 mg/day Mg citrate treatment in 16 patients (group 1). The control group included 16 Mg-non-treated HF patients (group 2). HRV was determined by a non-linear dynamics analysis, derived from the chaos theory, which calculates HRV-correlation dimension (HRV-CD). After 5 weeks, serum Mg (mmol/l) increased more significantly in group 1 (from 0.78+/-0.04 to 0.89+/-0.06, p<0.001), than in group 2 (from 0.79+/-0.07 to 0.84+/-0.06, p=0.042). IcMg and HRV-CD increased significantly only in group 1 (from 59+/-7 to 66+/-9 mmol/g cell protein, p=0.025, and from 3.47+/-0.42 to 3.94+/-0.36, p<0.001, respectively). In group 2, the differences in the respective parameters were 63+/-12 to 66+/-9 mmol/g cell protein (p=0.7) and 3.59+/-0.42 to 3.55+/-0.4 (p=0.8).
  
  
  CONCLUSIONS
  Mg administration to normomagnesemic patients with systolic HF increases serum Mg, icMg and HRV-CD. Increasing of HRV by Mg supplementation may prove beneficial to HF patients.
authors.affiliation: Department of Internal Medicine F, Assaf Harofeh Medical Center (Affiliated to the Sackler School of Medicine, Tel Aviv University), Zerifin 70300, Israel. internal6@asaf.health.gov.il
authors.forename: D
authors.initials: D
authors.lastname: Almoznino-Sarafian
authors.forename: G
authors.initials: G
authors.lastname: Sarafian
authors.forename: S
authors.initials: S
authors.lastname: Berman
authors.forename: M
authors.initials: M
authors.lastname: Shteinshnaider
authors.forename: I
authors.initials: I
authors.lastname: Tzur
authors.forename: N
authors.initials: N
authors.lastname: Cohen
authors.forename: O
authors.initials: O
authors.lastname: Gorelik
mesh_terms: D000368:Aged; D015897:Comorbidity; D003600:Cytosol / Q000378:metabolism; D015716:Electrocardiography, Ambulatory; D005260:Female; D054143:Heart Failure, Systolic / Q000188:drug therapy* / Q000453:epidemiology / Q000378:metabolism*; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008274:Magnesium / Q000008:administration & dosage* / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D011379:Prognosis; D016896:Treatment Outcome
chemical_list: D008274:Magnesium