title: Noninvasive quantification of blood potassium concentration from ECG in hemodialysis patients.
abstract: Blood potassium concentration ([K+]) influences the electrocardiogram (ECG), particularly T-wave morphology. We developed a new method to quantify [K+] from T-wave analysis and tested its clinical applicability on data from dialysis patients, in whom [K+] varies significantly during the therapy. To elucidate the mechanism linking [K+] and T-wave, we also analysed data from long QT syndrome type 2 (LQT2) patients, testing the hypothesis that our method would have underestimated [K+] in these patients. Moreover, a computational model was used to explore the physiological processes underlying our estimator at the cellular level. We analysed 12-lead ECGs from 45 haemodialysis and 12 LQT2 patients. T-wave amplitude and downslope were calculated from the first two eigenleads. The T-wave slope-to-amplitude ratio (TS/A) was used as starting point for an ECG-based [K+] estimate (KECG). Leave-one-out cross-validation was performed. Agreement between KECGand reference [K+] from blood samples was promising (error: -0.09 ± 0.59 mM, absolute error: 0.46 ± 0.39 mM). The analysis on LQT2 patients, also supported by the outcome of computational analysis, reinforces our interpretation that, at the cellular level, delayed-rectifier potassium current is a main contributor of KECGcorrelation to blood [K+]. Following a comprehensive validation, this method could be effectively applied to monitor patients at risk for hyper/hypokalemia.
authors.affiliation: Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.|Health Sciences and Technology Interdepartmental Center for Industrial Research, University of Bologna, Cesena, Italy.
authors.forename: Cristiana
authors.initials: C
authors.lastname: Corsi
authors.affiliation: Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.
authors.forename: Marilisa
authors.initials: M
authors.lastname: Cortesi
authors.affiliation: Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Callisesi
authors.affiliation: Mortara Instrument Inc., Milwaukee (WI), USA.
authors.forename: Johan
authors.initials: J
authors.lastname: De Bie
authors.affiliation: Molecular Cardiology, IRCCS Fondazione Salvatore Maugeri, Pavia, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Napolitano
authors.affiliation: Nephrology Dialysis, Hypertension Unit, Hospital Policlinico S.Orsola-Malpighi, Bologna, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Santoro
authors.affiliation: Mortara Instrument Inc., Milwaukee (WI), USA.
authors.forename: David
authors.initials: D
authors.lastname: Mortara
authors.affiliation: Department of Electrical, Electronic and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena, Italy.|Health Sciences and Technology Interdepartmental Center for Industrial Research, University of Bologna, Cesena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Severi
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000097:blood / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood*; D006435:Renal Dialysis; D055815:Young Adult
chemical_list: D011188:Potassium