title: Dynamic changes in bioelectrical impedance vector analysis and phase angle in acute decompensated heart failure.
abstract: OBJECTIVE
  To evaluate whether changes in hydration status (reflecting fluid retention) would be detected by bioelectrical impedance vector analysis (BIVA) and phase angle during hospitalization for acute decompensated heart failure (ADHF) and after clinical stabilization.
  
  
  METHODS
  Patients admitted to ADHF were evaluated at admission, discharge and after clinical stabilization (3 mo after discharge) for dyspnea, weight, brain natriuretic peptide, bioelectrical impedance resistance, reactance, and phase angle. Generalized estimating equations and chi-square detected variations among the three time points of evaluation.
  
  
  RESULTS
  Were included 57 patients: Mean age was 61 ± 13 y, 65% were male, LVEF was 25 ± 8%. During hospitalization there were improvements in clinical parameters and increase in resistance/height (from 250 ± 72 to 302 ± 59 Ohms/m, P < 0.001), reactance/height (from 24 ± 10 to 31 ± 9 Ohms/m, P < 0.001), and phase angle (from 5.3 ± 1.6 to 6 ± 1.6°, P = 0.007). From discharge to chronic stability, both clinical and BIVA parameters remained stable. At admission, 61% of patients had significant congestion by BIVA, and they lost more weight and had higher improvement in dyspnea during hospitalization (P < 0.05). At discharge, more patients were in the upper half of the graph (characterizing some degree of dehydration) while at chronic stability normal hydration status was more prevalent (P < 0.001).
  
  
  CONCLUSIONS
  BIVA and phase angle were able to detect significant changes in hydration status during ADHF, which paralleled the clinical course of recompensation, both acutely and chronically. The classification of congestion by BIVA at admission identified patients with more pronounced changes in weight and dyspnea during compensation.
authors.affiliation: Postgraduate Program in Cardiovascular Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Fernanda Donner
authors.initials: FD
authors.lastname: Alves
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Internal Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Gabriela Corrêa
authors.initials: GC
authors.lastname: Souza
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; School of Nursing, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Graziella Badin
authors.initials: GB
authors.lastname: Aliti
authors.affiliation: Postgraduate Program in Cardiovascular Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; School of Nursing, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Eneida Rejane
authors.initials: ER
authors.lastname: Rabelo-Silva
authors.affiliation: Postgraduate Program in Cardiovascular Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Internal Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Nadine
authors.initials: N
authors.lastname: Clausell
authors.affiliation: Postgraduate Program in Cardiovascular Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil; Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; Department of Internal Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: Biolo.andreia@gmail.com.
authors.forename: Andréia
authors.initials: A
authors.lastname: Biolo
mesh_terms: D000208:Acute Disease; D000368:Aged; D001823:Body Composition; D001835:Body Weight; D015331:Cohort Studies; D004417:Dyspnea / Q000175:diagnosis / Q000473:pathology; D017097:Electric Impedance; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000473:pathology; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D014883:Water-Electrolyte Imbalance / Q000175:diagnosis / Q000473:pathology
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: Bioelectric impedance analysis; Body composition; Heart failure; Hydration status; Phase angle