Avaliação da contratilidade segmentar na doença de Chagas utilizando a integral do gradiente intramiocárdico de velocidade (strain miocárdico) obtida pela ecocardiografia com Doppler tecidual Evaluation of segmentary contractility in Chagas' disease by using the integral of the myocardial velocity gradient (myocardial strain) obtained through tissue Doppler echocardiography

Abstract

OBJETIVO: Quantificar o percentual de contratilidade dos diversos segmentos miocárdicos, em portadores de doença de Chagas, através da medida do strain miocárdico e verificar diferenças na função contrátil radial e longitudinal ventricular entre as formas indeterminada e dilatada da miocardiopatia chagásica crônica quando comparadas a um grupo de indivíduos normais. MÉTODOS: Foram estudados 39 indivíduos, 20 (51,3%) do sexo masculino divididos em quatro grupos: Nl: 17 (43,6%) indivíduos normais; Ind: 7 (17,9%) portadores de doença de Chagas forma indeterminada; C1, 7 (17,9%) portadores de doença de Chagas forma crônica com fração de ejeção 50%. Após realização de ecocardiograma basal foram registradas as imagem em Doppler tecidual para a medida do strain miocárdico nos diversos segmentos aos cortes paraesternais, longitudinal e transversal, e apicais, de duas e quatro câmaras. RESULTADOS E CONCLUSÃO: O percentual de contração dos diversos segmentos miocárdicos, tanto em seu componente radial quanto longitudinal é maior nos indivíduos normais do que em portadores da forma crônica da doença de Chagas e naqueles com a forma indeterminada da doença quando comparado com chagásicos crônicos com FE OBJECTIVE: To quantify the percentage of contractility of different myocardial segments in patients with Chagas' disease by measuring myocardial strain and to assess the differences in the radial and longitudinal ventricular contractile function in the undetermined and dilated forms of chronic chagasic cardiomyopathy as compared with those in a group of healthy individuals. METHODS: The study comprised 39 individuals [20 (51.3%) of the male sex] divided into the following 4 groups: 1) Nl: 17 (43.6%) healthy individuals; 2) Und: 7 (17.9%) patients with the undetermined form of Chagas' disease; 3) C1: 7 (17.9%) patients with the chronic form of Chagas' disease with ejection fraction 50%. After performing baseline echocardiography, Doppler tissue images were recorded to measure myocardial strain in different segments on longitudinal and transversal parasternal, and apical 2- and 4-chamber views. RESULTS AND CONCLUSION: The percentage of contractility in the different myocardial segments, both the radial and longitudinal components, is greater in healthy individuals than in patients with the chronic form of Chagas' disease, and in those with the undetermined form of the disease as compared with that of chronic chagasic patients with EF < 50%. Left ventricular radial contractility is greater than left ventricular longitudinal contractility in all groups (Nl, Und, and Chronic). The data presented allow us to propose a progressive character of myocardial impairment in patients with Chagas' disease.

Keywords

• doença de Chagas
• ecocardiografia
• doppler tecidual
• strain miocárdico
• Chagas' disease
• echocardiography
• tissue Doppler
• myocardial strain