Efeitos da terapia ultrassônica de baixa intensidade sobre o infarto agudo do miocárdio em ratos

• Autor(a) principal: Freitas, Edineuza Aparecida de
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7950
• topic: Ultrasound; Myocardial infarction; Remodelling; Ultra-som; Infarto do miocárdio; Remodelamento; Fisiologia; 612

Background. The acute myocardial infarction is important cause of the mortality and morbidity in the world and Brazil. New therapeutic interventions are being tested isolated or in association with the already existing with the goal of preventing the progression or attenuate the remodeling in the heart infarcted. Among which-if the application of ultrasound (US) together with thrombolytic agents. However, in application of the energy ultrasonics as therapeutics postinfarction is evaluated only its possible effect as the agent thrombolytic, not being investigated to its possible involvement in the process of cicatrization of the area infarctada cardiac and functional parameters. Aims. In the face of such information, we aimed evaluate the effects of therapy ultrasonics transthoracic non-invasive of low intensity (NITUS) on the morphology and function of cardiac muscle of rats infarcted myocardial surgically after the 5th and 30th day. Methods. Male Wistar rats (200-250g) were weighed and randomly divided into eight groups with eight animals in each group. Four groups of animals were submitted to the induction of myocardium infarction through the occlusion permanent of the coronary artery descending left anterior, being two of these groups were sacrificed on the 5th day after the infarction and the five applications of therapy ultrasonics and the other two groups were sacrificed on the 30th day after the infarction and 5 applications of therapy ultrasonics. Four groups of animals were submitted to false-surgery (Sham), and two of these groups were sacrificed on the 5th day after false-surgery and the 5 applications of therapy ultrasonics and the other two groups were sacrificed on the 30th day after false-surgery and the 5 applications of therapy ultrasonics. The parameters of therapy ultrasonics were frequency of 1MHz, power 1W/cm2 , pulsed and time of application of 5 minutes. For the assessment of functional parameters was performed hemodynamic measurements of all the groups and after measurements the hearts were removed for morphometric analysis in order to assess the area of the scar of infarction. Hearts were cut in 4 slices being removed 3 cuts with a thickness of 8 micrometers of the third slice apical to base, and these were stained with picrosirius. Was used a video camera to catch an area which contained all the cuts. The image was caught with the use of the program AMCap and after the catch, this was filed. The stored image was 9 transferred to the program ImageJ 1.42q /java which was marked the area of the scar. Similarly, was marked throughout the area of ventricular wall, in order to obtain the relationship between the area of the scar and the total area of ventricular wall. Results. As regards the hemodynamic parameters, we observed that 30 days after the infarction there was a reduction in end diastolic pressure (PDE) (mmHg) of the group infarction + US when compared with group infarction (15±1.9 and 26±1.4, p<0.01, respectively). No significant difference in the area of the scar infarction between groups infarction and infarction+US in 5. day after acute myocardial infarction (31.6%±3.1 % and 34.5%±1.6, respectively). There was reduction in the area of the scar infarction in the group infarction+US when compared to group infarction (21.5%±1.4% and 26.2%±1.7%; p<0.05, respectively) on the 30th day after acute myocardial infarction. Conclusions. The therapy with US inside the established parameters, reduced the area of the scar of the infarction the group infarction+ US in the 30th days as well as it maintained the PDE inside physiologic values, probably because of influence in the phases inflammatory, proliferativa and of remodeling, which favors an increase in the speed of the inflammatory answer through the mobilization of inflammatory cells like neutrophils, macrophage, at the same time in which it stimulated to the degranulação of the mastocitos, which interfered in the mobilization of the leucocytos