Left atrial and ventricular deformation coupling in mitral regurgitation

This study aimed to evaluate left atrial (LA) and left ventricular (LV) deformation coupling in patients with degenerative (DMR) and functional mitral regurgitation (FMR). For this purpose, we analyzed the effect of MR on the relationship between LA and LV global longitudinal strain (GLS) independent of LA and LV geometry.

The investigation was conducted in two patient cohorts. Cohort A included 60 patients with severe MR (30 with DMR and 30 with FMR), compared to 30 healthy controls. Cohort B comprised 60 patients (30 with mild MR and 30 with severe MR) matched for LA and LV volumes and ejection fraction. Using speckle tracking-based strain imaging, simultaneous LA and LV deformation was assessed. LA GLS was more impaired than LV GLS in severe MR, with increased area and decreased slope of the LA-LV strain-strain loop, but these findings were no longer present when correcting for LA and LV volumes and ejection fraction.

Our findings indicate that the LV-LA deformation coupling in MR is mainly driven by chamber dimensions and (the forces driving the) displacement of the mitral annular plane, rather than the regurgitant volume load itself. Despite the presence of severe MR, the relationship between LA and LV strain is maintained, emphasizing the need for interpreting LA GLS in the context of both LV GLS and the geometrical properties of the chambers.

Graphical abstract