title: Effect of walking speed in heart failure patients and heart transplant patients.
abstract: BACKGROUND
  Chronic heart failure patients present higher cost of transport and some changes in pattern of walking, but the same aspects have not yet been investigated in heart transplant patients.
  
  
  METHODS
  The aim of this study was to investigate both metabolic and mechanicals parameters, at five different walking speeds on treadmill, in chronic heart failure and heart transplant patients. Twelve chronic heart failure patients, twelve healthy controls and five heart transplant patients participated in the study. Tridimensional kinematics data and oxygen uptake were collected simultaneously.
  
  
  RESULTS
  In both experimental groups the self-selected walking speed was lower than in controls, and lower than the expected optimal walking speed. At that speed all groups showed the best ventilatory efficiency. On contrary, chronic heart failure and heart transplant patients reached the minimum cost of transport and the maximum recovery at greater speeds than the self-selected walking speed. Their mechanical efficiency was lower than in controls, while their metabolic cost and mechanical work were on average larger.
  
  
  CONCLUSIONS
  We conclude that actions, like a physical training, that could increase the self-selected walking speed in these patients, could also increase their economy and optimize the mechanical parameters of walking. We propose a rehabilitation index, based on the theoretical optimal walking speed, to measure the improvements during a physical rehabilitation therapy. These results have an important clinical relevance and can help to improve the quality of life of heart failure and transplant patients.
authors.affiliation: Exercise Pathophysiology Research Laboratory, Cardiology Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, 2350 Ramiro Barcelos, Porto Alegre, Rio Grande do Sul 90035-903, Brazil; Biomechanics Research and Movement Analyses Laboratory, CENUR Litoral Norte, Universidad de la República, 1065 Florida, Paysandú 60000, Uruguay. Electronic address: renatalbona@gmail.com.
authors.forename: Renata L
authors.initials: RL
authors.lastname: Bona
authors.affiliation: Biomechanics Research and Movement Analyses Laboratory, CENUR Litoral Norte, Universidad de la República, 1065 Florida, Paysandú 60000, Uruguay; Exercise Research Laboratory, Department of Physical Education, School of Physical Education, Federal University of Rio Grande do Sul,750 Felizardo Furtado, Porto Alegre, Rio Grande do Sul 90690-200, Brazil. Electronic address: abonezi@gmail.com.
authors.forename: Artur
authors.initials: A
authors.lastname: Bonezi
authors.affiliation: Exercise Pathophysiology Research Laboratory, Cardiology Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, 2350 Ramiro Barcelos, Porto Alegre, Rio Grande do Sul 90035-903, Brazil. Electronic address: paula.silva312@gmail.com.
authors.forename: Paula Figueiredo
authors.initials: PF
authors.lastname: da Silva
authors.affiliation: Biomechanics Research and Movement Analyses Laboratory, CENUR Litoral Norte, Universidad de la República, 1065 Florida, Paysandú 60000, Uruguay. Electronic address: carlo.biancardi@gmail.com.
authors.forename: Carlo M
authors.initials: CM
authors.lastname: Biancardi
authors.affiliation: Exercise Research Laboratory, Department of Physical Education, School of Physical Education, Federal University of Rio Grande do Sul,750 Felizardo Furtado, Porto Alegre, Rio Grande do Sul 90690-200, Brazil. Electronic address: souza.castro@ufrgs.br.
authors.forename: Flávio Antônio
authors.initials: FA
authors.lastname: de Souza Castro
authors.affiliation: Department of Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, 2400 Ramiro Barcelos, Porto Alegre, Rio Grande do Sul 90035-003, Brazil. Electronic address: nclausell07@gmail.com.
authors.forename: Nadine Oliveira
authors.initials: NO
authors.lastname: Clausel
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D002908:Chronic Disease; D017281:Cost of Illness; D004734:Energy Metabolism / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000534:rehabilitation / Q000601:surgery; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D011788:Quality of Life; D014186:Transportation / Q000191:economics; D000072797:Walking Speed / Q000502:physiology*
keywords: Cost of transport; Heart disease; Mechanical work; Recovery