Vaturi Mordehay, Hadar Tanya, Yedidya Idit, Shapira Yaron, Monakier Daniel, Weisenberg Daniel E, Sagie Alex
Echocardiography Unit and Valvular Clinic, Department of Cardiology, Rabin Medical Center (Beilinson Campus), Petah Tikva, Israel.
Isr Med Assoc J. 2010 Mar;12(3):150-3.
Left atrial volume and exercise capacity are strong predictors of cardiovascular risk. Decreased exercise capacity is expected when LAV is increased due to its association with abnormal left ventricular filling pressure. However, LAV enlargement is expected in chronic mitral regurgitation as well.
To examine the link between LAV and exercise capacity in chronic MR and to determine whether larger LAV has indeed better exercise capacity in patients with chronic severe degenerative MR and good LV systolic function.
The study included asymptomatic patients with severe chronic degenerative MR and normal LV systolic function that underwent stress echocardiography. LAV was measured at rest using the biplane Simpson's method and indexed to body surface area. The cutoff of good exercise capacity was determined at 7 METS.
The patient group comprised 52 consecutive patients (age 60 +/- 14 years, 36 males). Two subgroups (19 vs. 33 patients), age- and gender-matched, were formed according to LAVi cutoff of 42 ml/m2. Those with higher LAVi had lower exercise capacity (P = 0.004) albeit similar MR grade, baseline blood pressure, LV function and size. Receiver-operator curve analysis revealed indexed LAV value of < or = 42 as 51% sensitive and 88% specific for predicting exercise capacity > 7 METS (AUC = 0.7, P = 0.03). In multivariate analysis, age, gender and LAVi were identified as independent predictors of exercise capacity.
In asymptomatic patients with severe chronic degenerative MR and normal LV systolic function, mild enlargement of the left atrium (< or = 42 ml/m2) is associated with good exercise capacity.
左心房容积和运动能力是心血管风险的强有力预测指标。由于左心房容积与左心室充盈压异常相关，当其增加时预计运动能力会下降。然而，慢性二尖瓣反流时也会出现左心房容积增大。
研究慢性二尖瓣反流患者左心房容积与运动能力之间的联系，并确定在慢性重度退行性二尖瓣反流且左心室收缩功能良好的患者中，较大的左心房容积是否确实具有更好的运动能力。
该研究纳入了无症状的重度慢性退行性二尖瓣反流且左心室收缩功能正常的患者，这些患者接受了负荷超声心动图检查。使用双平面辛普森法在静息状态下测量左心房容积，并将其与体表面积进行指数化。将良好运动能力的临界值确定为7代谢当量。
患者组包括52例连续患者（年龄60±14岁，男性36例）。根据左心房容积指数42 ml/m²的临界值，形成了两个年龄和性别匹配的亚组（19例对33例患者）。尽管二尖瓣反流分级、基线血压、左心室功能和大小相似，但左心房容积指数较高的患者运动能力较低（P = 0.004）。受试者工作特征曲线分析显示，左心房容积指数≤42对于预测运动能力>7代谢当量的敏感性为51%，特异性为88%（曲线下面积 = 0.7，P = 0.03）。在多变量分析中，年龄、性别和左心房容积指数被确定为运动能力的独立预测因素。
在无症状的重度慢性退行性二尖瓣反流且左心室收缩功能正常的患者中，左心房轻度增大（≤42 ml/m²）与良好的运动能力相关。
