Differential left atrial remodeling in LV diastolic dysfunction and mitral regurgitation.

OBJECTIVE

Chronic pressure and volume overload may cause different type of left atrial (LA) remodeling in left atrial enlargement (LAE) leading to different cardiovascular outcomes. These two different patterns of LA remodeling can be discriminated by LA eccentricity index (LAEi). The goal of our study was to evaluate an association between LAEi, LV diastolic dysfunction (LVDD), and mitral regurgitation (MR).

METHOD

LAEi was calculated from 3D of left atrium (LA): anteroposterior (D1), superoinferior (D2), mediolateral (D3), and LAEi = D2x2/ (D1+D3). LAE was described as elongated left atrium (EA) if LAEi > or = 1.27, and spherical left atrium (SA) if LAEi < 1.27.

RESULTS

A group of 501 patients (10.4%) with LAE were categorized into two subgroups; 232 (46.3%) with EA and 269 (53.7%) with SA based on LAEi. Among 108 patients (21.6%) with LVDD without MR, 102 had EA and only 6 had SA (P < 0.0001). The cohort of 155(30.1%) patients with MR without LVDD, only 8 had EA and143 had SA (P < 0.0001). Of the total group of 501 patients, 59 had persistent AF and in this subgroup only 10 patients had EA and 49 patients had SA (P < 0.0001). There was a statistically significant difference for AF rate between EA-patients with LVDD without MR and SA-patients with MR without LVDD (P < 0.001).

CONCLUSIONS

LVDD may contribute to pressure overload LA remodeling in a way quite different from volume overload LA remodeling by MR. LAEi can discriminate two different LA morphologies with significantly different potential outcomes. It may identify patients associated with a higher rate of AF with a higher cardiovascular risk.