title: Electrolyte concentration during haemodialysis and QT interval prolongation in uraemic patients.
abstract: OBJECTIVE
  To assess the effect of different combinations of potassium and calcium concentrations on QT interval in the dialysis bath in uraemic patients.
  
  
  RESULTS
  Sixteen haemodialysis (HD) patients underwent a 24 h Holter recording before and during HD sessions with six randomized combinations of electrolytes concentrations of the dialysis bath (K(+), 2 and 3 mmol/L; Ca(2+), 1.25, 1.5, and 1.75 mmol/L). The effect of different dialysis baths on QT interval was significant (P < 0.05). The longest mean QTc was observed with the lowest K(+) (2 mmol/L) and Ca(2+) concentrations (1.25 mmol/L), whereas the shortest mean QTc was observed with the highest K(+) (3 mmol/L) and Ca(2+) concentrations (1.75 mmol/L). QTc was >440 ms in 9 of 16 patients (56%) at the lowest Ca(2+) and K(+) concentrations, and in 3 of 16 patients (18%) at the highest electrolytes level. Changes in QTc during the HD sessions were inversely correlated with that in total Ca and Ca(2+) plasma concentrations (P < 0.0001).
  
  
  CONCLUSIONS
  Changes in ventricular repolarization duration associated with HD largely depend on the concentrations of Ca(2+) and K(+) in the dialysis bath. These findings may have important implications for the choice of the electrolytes concentration of the dialysis bath during the HD session.
authors.affiliation: Dipartimento di Medicina Clinica e Prevenzione, Università degli Studi Milano-Bicocca, Via Cadore 48, 20052-Monza, Italy. simonetta.genovesi@unimib.it
authors.forename: Simonetta
authors.initials: S
authors.lastname: Genovesi
authors.forename: Chiara
authors.initials: C
authors.lastname: Dossi
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Viganò
authors.forename: Eleonora
authors.initials: E
authors.lastname: Galbiati
authors.forename: Federico
authors.initials: F
authors.lastname: Prolo
authors.forename: Andrea
authors.initials: A
authors.lastname: Stella
authors.forename: Marco
authors.initials: M
authors.lastname: Stramba-Badiale
mesh_terms: D000368:Aged; D002118:Calcium / Q000032:analysis*; D015314:Dialysis Solutions / Q000737:chemistry*; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications / Q000175:diagnosis*; D008297:Male; D011188:Potassium / Q000032:analysis*; D006435:Renal Dialysis; D014057:Tomography, X-Ray Computed; D014511:Uremia / Q000150:complications / Q000534:rehabilitation*
chemical_list: D015314:Dialysis Solutions; D011188:Potassium; D002118:Calcium