Left atrium volume and function changes during stress in patients with primary mitral regurgitation and preserved left ventricular ejection fraction.

INTRODUCTION: Patients with primary mitral regurgitation (MR) usually remain asymptomatic for a long time due to compensatory mechanisms and an adequate treatment could be delayed. Stress echocardiography and speckle-tracking analysis could help to evaluate impaired left atrium (LA) function before the manifestation of clinically significant myocardial changes in asymptomatic patients with primary MR and preserved left ventricular (LV) ejection fraction (EF).

METHODS: This study prospectively enrolled 91 patients with preserved LV EF (≥60%) at rest, of which 60 patients had moderate-to-severe MR and 31 were healthy controls. Rest and stress (bicycle ergometry) echocardiography and speckle-tracking offline analysis were performed.

RESULTS: In MR group LA volume indices were higher at rest and during stress, while LA reservoir, conduit, and contractile fractions were decreased ( p < .005). LA deformation parameters at rest were similar in both groups. During maximum stress LA conduit, contractile fractions and reservoir strain were lower ( p < .05) in patients with MR. Indices of LA volume were related to SPAP at rest and during stress. Higher NT-proBNP concentrations was associated with higher LA volume indices, decreased contractile and reservoir functions during peak stress ( p < .05). LA volume indices, LA EF, and filling index at rest could predict exercise-induced pulmonary hypertension (EIPH) ( p < .05).

CONCLUSIONS: In patients with primary MR and preserved LV EF, LA parameters are related to SPAP and NT-pro-BNP concentration. LA volume indices, LA EF and LA filling index are predictors of EIPH.