title: Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.
abstract: The objective of the present study is to evaluate the acute effects of low-level laser therapy (LLLT) on functional capacity, perceived exertion, and blood lactate in hospitalized patients with heart failure (HF). Patients diagnosed with systolic HF (left ventricular ejection fraction <45 %) were randomized and allocated prospectively into two groups: placebo LLLT group (n = 10)-subjects who were submitted to placebo laser and active LLLT group (n = 10)-subjects who were submitted to active laser. The 6-min walk test (6MWT) was performed, and blood lactate was determined at rest (before LLLT application and 6MWT), immediately after the exercise test (time 0) and recovery (3, 6, and 30 min). A multi-diode LLLT cluster probe (DMC, São Carlos, Brazil) was used. Both groups increased 6MWT distance after active or placebo LLLT application compared to baseline values (p = 0.03 and p = 0.01, respectively); however, no difference was observed during intergroup comparison. The active LLLT group showed a significant reduction in the perceived exertion Borg (PEB) scale compared to the placebo LLLT group (p = 0.006). In addition, the group that received active LLLT showed no statistically significant difference for the blood lactate level through the times analyzed. The placebo LLLT group demonstrated a significant increase in blood lactate between the rest and recovery phase (p < 0.05). Acute effects of LLLT irradiation on skeletal musculature were not able to improve the functional capacity of hospitalized patients with HF, although it may favorably modulate blood lactate metabolism and reduce perceived muscle fatigue.
authors.affiliation: Department of Bioscience, Federal University of Sao Paulo, Silva Jardim, Santos, SP, 11050-240, Brazil. carolinebublitz@yahoo.com.br.|Department of Human Motion Sciences and Cardiology and Cardiovascular Surgery Discipline, Federal University of Sao Paulo, Sao Paulo, Brazil. carolinebublitz@yahoo.com.br.
authors.forename: Caroline
authors.initials: C
authors.lastname: Bublitz
authors.affiliation: Department of Bioscience, Federal University of Sao Paulo, Silva Jardim, Santos, SP, 11050-240, Brazil.
authors.forename: Ana Claudia Muniz
authors.initials: AC
authors.lastname: Renno
authors.affiliation: Department of Human Motion Sciences and Cardiology and Cardiovascular Surgery Discipline, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Rodrigo Santin
authors.initials: RS
authors.lastname: Ramos
authors.affiliation: Department of Bioscience, Federal University of Sao Paulo, Silva Jardim, Santos, SP, 11050-240, Brazil.
authors.forename: Livia
authors.initials: L
authors.lastname: Assis
authors.affiliation: Santa Casa de Misericórdia de Santos Hospital, Santos, Sao Paulo, Brazil.
authors.forename: Carlos Alberto Cyrillo
authors.initials: CA
authors.lastname: Sellera
authors.affiliation: Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos, Sao Paulo, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Trimer
authors.affiliation: Cardiopulmonary Physiotherapy Laboratory, Nucleus of Research in Physical Exercise, Federal University of Sao Carlos, Sao Paulo, Brazil.
authors.forename: Audrey
authors.initials: A
authors.lastname: Borghi-Silva
authors.affiliation: Department of Physical Therapy and Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.affiliation: Department of Human Motion Sciences and Cardiology and Cardiovascular Surgery Discipline, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Solange
authors.initials: S
authors.lastname: Guizilini
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology; D006760:Hospitalization; D006801:Humans; D007773:Lactates / Q000097:blood*; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000528:radiation effects*; D018482:Muscle, Skeletal / Q000528:radiation effects*; D010865:Pilot Projects
chemical_list: D007773:Lactates
keywords: 6-min walk test; Functional capacity; Heart failure; Lactate; Low-level laser therapy (LLLT)