Left atrial function analysis in patients with functional mitral regurgitation associated with dilated cardiomyopathy / Análise da função atrial esquerda em pacientes com insuficiência mitral funcional associada à miocardiopatia dilatada

ABSTRACT

BACKGROUND: Functional mitral regurgitation (FMR) is associated with dilated cardiomyopathy (DC), heart failure (HF), and worsening left atrial function (LAF). Patients with DC and FMR may present left atrial dysfunction resulting from both ventricular dysfunction and valve disease, but it is unknown whether the presence of valve disease will lead to greater LAF impairment. OBJECTIVE: This study aimed to evaluate the relationship between LAF parameters and FMR degree in patients with DC. METHODS: This cross-sectional observational study included 214 patients with DC, 46 without FMR (control group) and 168 with mild, moderate or severe FMR. An LAF analysis was performed by speckle tracking echocardiography (STE) and atrial volumetric variation. RESULTS: LAF analyzed by STE by means of reservoir strain, conduit strain and active contraction strain was reduced in the sample, with values of 14.3%, 8.49% and 5.92%, respectively. FMR degree was significantly associated with reservoir strain (0.27 ± 0.16 versus 0.15 ± 0.09; p < 0.001) and contraction strain (19.2 ± 7.3 versus 11.2 ± 2.7; p < 0.001). FMR was also associated with a reduced LAF assessed by volumetric analysis: total atrial emptying fraction of 0.51 ± 0.13 versus 0.34 ± 0.11 and active atrial emptying fraction of 0 .27 ± 0.16 versus 0.15 ± 0.09 (p < 0.001). CONCLUSION: In a population with DC, FMR was associated with reduced LAF assessed by STE and atrial volume variation.

RESUMO

FUNDAMENTO A insuficiência mitral funcional (IMF) está associada à miocardiopatia dilatada (MD), à insuficiência cardíaca (IC) e à piora da função atrial esquerda (FAE). A FAE pode decair tanto pela disfunção ventricular quanto pela valvopatia, mas não se sabe se esta leva a um prejuízo maior da FAE. OBJETIVO: Avaliar a relação entre a piora de parâmetros de FAE com o grau de IMF, em pacientes com MD. MÉTODOS: Trata-se de estudo observacional transversal, que incluiu 214 pacientes com MD, sendo 46 sem IMF (controle) e 168 com IMF discreta, moderada ou grave. A análise da FAE foi realizada por ecocardiografia por speckle tracking (STE) e por variação volumétrica atrial. RESULTADOS: A FAE, analisada por STE­ por meio do strain de reservatório, conduto e contração ativa ­ encontrou-se reduzida na amostra, com valores respectivos de 14,3%, 8,49% e 5,92%. O grau de IMF associou-se significativamente com os valores do strain de reservatório (0,27±0,16 versus 0,15±0,09; p <0,001. CONCLUSÃO: Em uma população com MD, a presença de IMF associa-se à redução da FAE de reservatório e de contração, avaliada por STE e pela variação volumétrica atrial.