ABSTRACT
Cardiac interstitial fibrosis may contribute to ventricular dysfunction and the prognosis of patients with dilated cardiomyopathy. The objective of the present study was to determine if total myocardial collagen content and collagen type III/I (III/I ratio) mRNAs differ in hypertensive, alcoholic, and idiopathic dilated cardiomyopathy subjects. Echocardiography and exercise cardiopulmonary testing were performed in patients with idiopathic (N = 22), hypertensive (N = 12), and alcoholic (N = 11) dilated cardiomyopathy. Morphometric analysis of collagen was performed in fragments obtained by endomyocardial biopsy with picrosirius red staining. The collagen III/I ratio was determined by reverse transcription polymerase chain reaction. Samples of controls (N = 10) were obtained from autopsy. Echocardiographic variables and maximal oxygen uptake were not different among dilated cardiomyopathy groups. Collagen was higher in all dilated cardiomyopathy groups (idiopathic, hypertensive and alcoholic, 7.36 ± 1.09 percent) versus controls (1.12 ± 0.18 percent), P < 0.05. Collagen was lower in idiopathic dilated cardiomyopathy (4.97 ± 0.83 percent) than hypertensive (8.50 ± 1.11 percent) and alcoholic (10.77 ± 2.09 percent) samples (P < 0.005 for both). The collagen III/I ratio in all samples from dilated cardiomyopathy patients was higher compared to that in controls (0.29 ± 0.04, P < 0.05) but was the same in the samples from idiopathic (0.77 ± 0.07), hypertensive (0.75 ± 0.07), and alcoholic (0.81 ± 0.16) dilated cardiomyopathy groups. Because of the different physical properties of the types of collagen, the higher III/I ratio may contribute to progressive ventricular dilation and dysfunction in dilated cardiomyopathy patients.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Alcoholism/metabolism , Cardiomyopathy, Dilated/metabolism , Collagen Type I/analysis , Collagen Type III/analysis , Hypertension/metabolism , RNA, Messenger/analysis , Alcoholism/complications , Biopsy , Case-Control Studies , Cardiomyopathy, Dilated/etiology , Collagen Type I/genetics , Collagen Type III/genetics , Echocardiography , Exercise Test , Hypertension/complications , Myocardium/chemistry , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
A biópsia endomiocárdica é o principal meio para estabelecermos, de forma fidedigna, o diagnóstico de rejeiçäo aguda, que pode ser dos tipos humoral, celular ou misto. A rejeiçäo aguda humoral é rara, mediada por anticorpos e caracteriza-se por lesöes da microcirculaçào miocárdica, sen infiltrado inflamatório. Por causa do lado, a rejeiçäo aguda celular é caracterizada pela infiltraçäo do miocárdio por células linfocitárias. Se existe agressäo dos miócitos pelo infiltrado inflamatório, a rejeiçäo éraduada como moderada ou severa e necessita de tratamento. O acompanhamento evolutivo dos episódios de rejeiçäo é fundamental. Processos infecciosos que acometem o miocárdio, particularmente a toxoplasmose e a recidiva da doença de Chagas, podem ser diagnosticados pela biópisa endomiocárdica. Técnicas imuno-histoquímicas säo de grande valia para o estabelecimento desses diagnósticos. Alteraçöes secundárias a isquemia perioperatória, caracterizadas por microinfartos, podem estar presentes nas primeiras bóisas e näo devem ser confundidas com rejeiçäo aguda.