Acute Impact of Balloon Mitral Valvotomy on Left Atrial Functions in Mitral Stenosis

摘要

Background: Rheumatic mitral stenosis (MS) is associated with progressive impairment of left atrial (LA) mechanicalfunctions. This study was conducted to assess the acute impact of Balloon Mitral Valvotomy (BMV) on these functions.Methods: This single centre observational study included 25 patients with severe MS (aged 34.1 ± 7.1 years, with meanmitral valve area of 0.74 ± 0.13 cm2), in sinus rhythm, who underwent successful BMV at our hospital. Phasic LA volumes(Vmax: maximal LA volume, Vmin: minimal LA volume, and Vp: LA volume at the onset of P-wave) were measured by modifiedSimpson’s method. Parameters of LA reservoir function i.e. LA total emptying fraction (LATEF) and LA expansionindex (LAEI); conduit function i.e. LA passive emptying fraction (LAPEF); and pump function i.e. LA active emptyingfraction (LAAEF) were calculated from these volumes. All these parameters were evaluated before and 24-48 hours afterBMV. Results: Successful BMV led to significant reduction in Vmax (p < 0.001), Vmin (p < 0.001), and Vp (p < 0.001). Therewas a significant increase in LATEF (p= 0.001) and LAEI (p= 0.002). LAPEF increased insignificantly (p= 0.057), whilethere was no significant change in LAAEF (p =0.127) after BMV. Conclusion: Successful BMV leads to early improvementin left atrial reservoir and conduit functions, without significantly affecting left atrial pump function. Whether theseacute changes translate into long term left atrial reverse remodelling and clinical benefits thereof needs to be establishedby further studies.