title: Fractal Dimension in Quantifying Experimental-Pulmonary-Hypertension-Induced Cardiac Dysfunction in Rats.
abstract: BACKGROUND
  Right-sided heart failure has high morbidity and mortality, and may be caused by pulmonary arterial hypertension. Fractal dimension is a differentiated and innovative method used in histological evaluations that allows the characterization of irregular and complex structures and the quantification of structural tissue changes.
  
  
  OBJECTIVE
  To assess the use of fractal dimension in cardiomyocytes of rats with monocrotaline-induced pulmonary arterial hypertension, in addition to providing histological and functional analysis.
  
  
  METHODS
  Male Wistar rats were divided into 2 groups: control (C; n = 8) and monocrotaline-induced pulmonary arterial hypertension (M; n = 8). Five weeks after pulmonary arterial hypertension induction with monocrotaline, echocardiography was performed and the animals were euthanized. The heart was dissected, the ventricles weighed to assess anatomical parameters, and histological slides were prepared and stained with hematoxylin/eosin for fractal dimension analysis, performed using box-counting method. Data normality was tested (Shapiro-Wilk test), and the groups were compared with non-paired Student t test or Mann Whitney test (p < 0.05).
  
  
  RESULTS
  Higher fractal dimension values were observed in group M as compared to group C (1.39 ± 0.05 vs. 1.37 ± 0.04; p < 0.05). Echocardiography showed lower pulmonary artery flow velocity, pulmonary acceleration time and ejection time values in group M, suggesting function worsening in those animals.
  
  
  CONCLUSIONS
  The changes observed confirm pulmonary-arterial-hypertension-induced cardiac dysfunction, and point to fractal dimension as an effective method to evaluate cardiac morphological changes induced by ventricular dysfunction.
authors.affiliation: Curso de Fisioterapia, UNOESTE, Presidente Prudente, São Paulo, Brazil.
authors.forename: Francis Lopes
authors.initials: FL
authors.lastname: Pacagnelli
authors.affiliation: Curso de Fisioterapia, UNOESTE, Presidente Prudente, São Paulo, Brazil.
authors.forename: Ana Karênina Dias de Almeida
authors.initials: AK
authors.lastname: Sabela
authors.affiliation: Curso de Fisioterapia, UNOESTE, Presidente Prudente, São Paulo, Brazil.
authors.forename: Thaoan Bruno
authors.initials: TB
authors.lastname: Mariano
authors.affiliation: Departamento de Fisioterapia, FCT, UNESP, Presidente Prudente, São Paulo, Brazil.
authors.forename: Guilherme Akio Tamura
authors.initials: GA
authors.lastname: Ozaki
authors.affiliation: Departamento de Educação Física, UNOESTE, Presidente Prudente, São Paulo, Brazil.
authors.forename: Robson Chacon
authors.initials: RC
authors.lastname: Castoldi
authors.affiliation: Departamento de Fisioterapia, FCT, UNESP, Presidente Prudente, São Paulo, Brazil.
authors.forename: Edna Maria do
authors.initials: EM
authors.lastname: Carmo
authors.affiliation: Departamento de Morfologia, UNESP, Botucatu, São Paulo, Brazil.
authors.forename: Robson Francisco
authors.initials: RF
authors.lastname: Carvalho
authors.affiliation: Faculdade de Medicina, UNESP, Botucatu, São Paulo, Brazil.
authors.forename: Loreta Casquel
authors.initials: LC
authors.lastname: Tomasi
authors.affiliation: Faculdade de Medicina, UNESP, Botucatu, São Paulo, Brazil.
authors.forename: Katashi
authors.initials: K
authors.lastname: Okoshi
authors.affiliation: Departamento de Fisioterapia, FCT, UNESP, Presidente Prudente, São Paulo, Brazil.
authors.forename: Luiz Carlos Marques
authors.initials: LC
authors.lastname: Vanderlei
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004452:Echocardiography; D017709:Fractals; D006333:Heart Failure / Q000209:etiology* / Q000473:pathology* / Q000503:physiopathology; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D016686:Monocrotaline; D032383:Myocytes, Cardiac / Q000473:pathology; D017208:Rats, Wistar; D012016:Reference Values; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000473:pathology / Q000503:physiopathology; D018497:Ventricular Dysfunction, Right / Q000473:pathology / Q000503:physiopathology
chemical_list: D016686:Monocrotaline