左心房容积指数在无症状重度主动脉瓣狭窄患者中的临床应用

目的探讨左心房容积指数在诊断无症状重度主动脉瓣狭窄(AS)患者中的应用价值。方法收集左心室射血分数(LVEF)>50%重度AS患者48例,根据有无临床症状分为有症状AS组及无症状AS组,每组各24例。采用超声心动图测量左心室腔大小及左心室质量(LVMI),通过Simpson法测得左心房容积指数,PWD测量二尖瓣舒张早期和晚期血流速度峰值(E、A),DTI测量二尖瓣环舒张早期及舒张晚期血流速度峰值(Em、Am)。根据重度AS患者临床症状鉴别标准构建ROC曲线。LAVI与超声参数的相关性采用Spearman和Pearson相关分析;对LAVI增大的其他主要影响因素进行多因素回归分析。结果有症状AS组较无症状AS组AV、MPG、PWT、SWT均增加(P均<0.05);有症状AS组LAVI明显高于无症状AS组(P=0.001)。LAVI预测有症状重度AS患者的最佳界值为39.85ml/m2,曲线下面积0.959,敏感度95.5%,特异度68.2%;LAVI与E/Em、LVMI呈正相关(r=0.639、0.658,P均<0.001)。多因素回归分析结果显示,E/Em和LVMI是LAVI的独立影响因子。结论 LAVI能预测无症状重度AS,且与左心室舒张功能指标有很好的相关性。

Clinical application of left atrial volume index in patients with asymptomatic severe aortic stenosis

Objective To explore the application value of left atrial volume index (LAVI) in patients with asymptomatic severe aortic stenosis (AS). Methods Forty-eight patients with severe AS and left ventricular (LV) ejection fraction >50% were divided into symptomatic severe AS group and asymptomatic severe AS group (each n=24). Echocardiography assessed LV dimension and left ventricular mass index (LVMI). LAVI was obtained by the biplane Simpson. Transmitral E, A diastolic velocitie and E/A ratio was measured by PWD. Early (Em) and late (Am) diastolic velocities of the lateral mitral annulus were measured by DTI. ROC curve of LAVI was established by differentiating standard of clinical symptoms. The correlation between LAVI and echocardiographic indexes was performed with Spearman and Pearson correlation analysis. Multivariate regression analysis was performed to define the independent variables associated with LAVI. Results Compared with asymptomatic severe AS group, AV, MPG, PWT, SWT in symptomatic severe AS group increased (all P<0.05); LAVI was signficantly higher in symptomatic severe AS group than that in asymptomatic severe AS group (P=0.001). Cut-off point of LAVI was 39.85 ml/m² in predicting symptomatic severe AS, the area under the ROC curve was 0.959, the sensitivity, specifcity was 95.5%, 68.2%, respectively. LAVI was positively correlated with E/Em (r=0.639, P<0.001) and LVMI (r=0.658, P<0.001). Multiple linear regression analysis revealed that LVMI and E/Em were the independent predictors of increasing LAVI in severe AS. Conclusion LAVI can predict asymptomatic severe AS, which is correlated with ventricular diastolic function parameters.