engleski

The impact of fibrosis on atrial regional and global function in severe mitral regurgitation-an intraoperative transesophageal echo study.

Purpose: The impact of acute changes in atrial loading conditions and the influence of atrial fibrosis on it’s function is not well understood. We aimed to study the effects of acute reversal of LA volume overload and the relation between atrial fibrosis and echo indices of LA function in patients with mitral regurgitation (MR). Methods: We studied 13 patients in sinus rhythm undergoing cardiac surgery for severe MR. An intraoperative TEE exam including Tissue Doppler Imaging (TDI) was acquired pre- and immediately post-procedurally. LA biopsies were obtained during surgery and stained with Mallory’s trichrome to assess for fibrosis. Results: A nonsignificant reduction in LA volumes occurred after surgery. The LA emptying index (EI) (151.8±93.0 vs. 87.6±34.1%, p=0.02) and LA passive emptying fraction (39.5±14.3 vs 23.2±9.3%, p<0.01) were significantly reduced postprocedurally while no significant change in LA active emptying fraction was measured. Peak strain-rate during ventricular contraction (SRI S’-LA reservoir function) and peak SRI during atrial contraction (SRI A’-LA contractile function) were reduced postoperatively (3.1±1.2 vs. 1.7±0.8, p<0.01 ; -2.6±1.5 vs.-1.4±1.5, p=0.049, respectively). LA conduit function (SRI E’) did not change significantly. A negative correlation between fibrosis and preoperative SRI A’ and LA EI was noted (r=-0.68, p=0.02 ; r=-0.67, p=0.03, respectively). Conclusions: Acute reversal of LA volume overload is reflected in reduced LA function, both global (conduit, reservoir) and regional (contractile, reservoir). Furthermore, LA fibrosis impacts it's contractile and reservoir function. 2D and TDI echo techniques provide valuable insight into atrial ultrastructural remodeling and its impact on regional and global LA function.

Atrial fibrosis; left atrium; volume overload; mitral regurgitation; Tissue Doppler

nije evidentirano