Pacagnelli Francis Lopes, Sabela Ana Karênina Dias de Almeida, Mariano Thaoan Bruno, Ozaki Guilherme Akio Tamura, Castoldi Robson Chacon, Carmo Edna Maria do, Carvalho Robson Francisco, Tomasi Loreta Casquel, Okoshi Katashi, Vanderlei Luiz Carlos Marques
Curso de Fisioterapia, UNOESTE, Presidente Prudente, São Paulo, Brazil.
Departamento de Fisioterapia, FCT, UNESP, Presidente Prudente, São Paulo, Brazil.
Arq Bras Cardiol. 2016 Jul;107(1):33-9. doi: 10.5935/abc.20160083. Epub 2016 May 24.
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.
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.
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).
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.
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.
右心衰竭发病率和死亡率高，可能由肺动脉高压引起。分形维数是组织学评估中一种独特的创新方法，可用于表征不规则和复杂结构，并对结构组织变化进行量化。
除了进行组织学和功能分析外，评估分形维数在使用野百合碱诱导肺动脉高压大鼠心肌细胞中的应用。
将雄性Wistar大鼠分为2组：对照组（C；n = 8）和野百合碱诱导的肺动脉高压组（M；n = 8）。用野百合碱诱导肺动脉高压5周后，进行超声心动图检查，然后对动物实施安乐死。解剖心脏，称量心室重量以评估解剖学参数，制备组织学切片并用苏木精/伊红染色以进行分形维数分析，采用盒计数法进行。对数据进行正态性检验（Shapiro-Wilk检验），并使用非配对学生t检验或Mann-Whitney检验对组间进行比较（p < 0.05）。
与C组相比，M组观察到更高的分形维数值（分别为1.39 ± 0.05和1.37 ± 0.04；p < 0.05）。超声心动图显示M组肺动脉流速、肺动脉加速时间和射血时间值较低，表明这些动物的功能恶化。
观察到的变化证实了肺动脉高压诱导的心脏功能障碍，并表明分形维数是评估心室功能障碍引起的心脏形态学变化的有效方法。
