Sasson Z, Rasooly Y, Gupta R, Rasooly I
Department of Medicine, Wellesley Hospital, University of Toronto, Ontario, Canada.
Can J Cardiol. 1996 Mar;12(3):257-63.
Left atrial (LA) enlargement has been reported in the obese. However, its prevalence in the healthy obese, clinical correlates and relation to left ventricular (LV) mass and diastolic function have been little investigated.
Thirty-five consecutive, healthy, normotensive obese (body mass index greater than 28, mean +/- SD 34.2 +/- 2.3 kg/m2) and 35 nonobese subjects (body mass index 24.6 +/- 2.3 kg/m2) comparable in age and sex underwent echocardiographic measurements of LA posteroanterior (parasternal view), mediolateral and superoinferior (apical views) dimensions, aortic root diameter, LV mass and Doppler assessment of LV diastolic function. LA enlargement was defined as a posteroanterior dimension greater than 40 mm. A ratio of LA posteroanterior dimension to aortic root diameter greater than 1.4 was used as an index for disproportionate LA enlargement.
LA enlargement was more frequent in the obese than in the nonobese (37% versus 6%, P<0.0001). Similarity, disproportionate LA enlargement was more frequent in the obese (34% versus 6%, P<0.0001). LA posteroanterior dimension correlated well with body mass index (r=0.52, P<0.0001) and LV mass (r=0.56, P<0.0001), and weakly with blood pressure (r=0.28, P<0.02). There was no significant correlation with LV diastolic function, age or sex. In multivariate analysis (multiple r=0.61, P<0.0001), LA posteroanterior dimension correlated significantly only with mass (P<0.005), and the association with body mass index and blood pressure became nonsignificant. Similar results were obtained when LA posteroanterior dimension was replaced with mediolateral or superoinferior dimensions.
LA enlargement is frequent in the normotensive, otherwise healthy obese and correlates well with LV mass. It is not mediated through impairment of LV diastolic function, and likely reflects a physiological adaptation of the heart to the obese state. Further studies are needed to determine whether LA enlargement in the obese is associated with adverse long term outcome.
肥胖人群中已报道存在左心房（LA）增大。然而，健康肥胖人群中LA增大的患病率、临床相关因素以及与左心室（LV）质量和舒张功能的关系鲜有研究。
连续纳入35名健康、血压正常的肥胖者（体重指数大于28，平均±标准差为34.2±2.3kg/m²）和35名年龄及性别相匹配的非肥胖者（体重指数为24.6±2.3kg/m²），对其进行超声心动图测量，包括LA前后径（胸骨旁切面）、内外径和上下径（心尖切面）、主动脉根部直径、LV质量以及LV舒张功能的多普勒评估。LA增大定义为前后径大于40mm。LA前后径与主动脉根部直径之比大于1.4被用作LA不成比例增大的指标。
肥胖者中LA增大比非肥胖者更常见（37%对6%，P<0.0001）。同样，肥胖者中LA不成比例增大也更常见（34%对6%，P<0.0001）。LA前后径与体重指数（r=0.52，P<0.0001）和LV质量（r=0.56，P<0.0001）密切相关，与血压的相关性较弱（r=0.28，P<0.02）。与LV舒张功能、年龄或性别无显著相关性。在多变量分析中（复相关系数=0.61，P<0.0001），LA前后径仅与质量显著相关（P<0.005），与体重指数和血压的相关性不再显著。当用内外径或上下径替代前后径时，得到了类似的结果。
血压正常、其他方面健康的肥胖者中LA增大很常见，且与LV质量密切相关。它并非由LV舒张功能受损介导，可能反映了心脏对肥胖状态的一种生理适应。需要进一步研究来确定肥胖者中LA增大是否与不良长期预后相关。
